The authors would like to acknowledge the support of Ten Cate Advanced Materials in the form of free material supply to the work described in this paper.

1. Peça de corte e preparação para a soldadura ultra-sônica <ol><li> Cortar amostras rectangulares medindo 25,4 milímetros x 101,6 milímetros a partir de um laminado compósito termoplástico maior usando uma técnica de corte que impede a deslaminação das arestas das amostras (por exemplo, diamante-serra ou de corte por jacto de água). Nota: As dimensões das amostras são baseados na norma ASTM D 1002 padrão. <ol><li> Uma vez que a força das juntas soldadas depende da orientação das fibras sobre as superfícies a serem soldadas 10, tomar cuidado para cortar todas as amostras na mesma orientação. </li></ol></li><li> Após o corte, as amostras secas num forno de acordo com as recomendações do fabricante, no caso da resina de termoplástico tende a absorver a humidade (por exemplo, 6 horas a 135 ° C durante fibra de carbono de seis camadas reforçadas polieterimida, CF / PEI, as amostras). </li><li> Cortar directores de energia planas feitas de película termoplástica puro (mesma resina que a matriz no compósito) de tamanho (cerca de 26 milímetros x 26 mm) com uma espessura de pelo menos 0,25 mm. Se necessário, secar o diretor de energia seguindo as recomendações do fabricante (por exemplo, 1 hora a 135 ° C, para o diretor de energia PEI). </li><li> Antes de soldar, inspecionar amostras de um por um para cantos desagregadas e descartar, se necessário. Limpá-los usando um desengordurante e um pano de algodão. Limpe os directores de energia planas seguindo o mesmo procedimento. </li></ol> 2. Ultrasonic Welding da única volta cupons de cisalhamento Nota: um microprocessador controlado soldador ultra-sónico capaz de soldar na amplitude constante é utilizado neste passo. Os dados de processo saídas soldador, tais como potência dissipada e deslocamento do sonotrodo versus tempo para o software de aquisição de dados de um computador. Um gabarito custom-built projetado e fabricado para posicionar com precisão e prender amostras de colo de corte individuais durante a soldagem ultra-sônica é usada neste passo (veja a Figura 1). Figura 1. Ultrasonic soldador e configuração de soldagem custom-built utilizado neste estudo. 1: sonotrodo, 2: plataforma deslizante, 3: braçadeira para o espécime superiores (ligados a 2), e 4: braçadeira para o espécime mais baixas (Reproduzido de referência 4 com permissão de Elsevier.) <a href="https://www.jove.com/files/ftp_upload/53592/53592fig1large.jpg" target="_blank">por favor, clique aqui para ver uma versão maior desta figura.</a> <ol><li> Preencher uma folha diário de bordo antes de cada experiência de soldagem. <ol><li> Tome nota dos seguintes parâmetros: RT e umidade, de referência configuração de soldagem, tipo de sonotrodo, o número de amostras e materiais, largura e espessura de amostras superior e inferior, e da espessura do diretor de energia. </li></ol></li><li> Ligue o soldador ultra-som e computador. Inicie o software de aquisição de dados e abrir uma nova sessão. </li><li> Se ainda não estiver no lugar, mudar o sonotrode para um sonotrodo cilíndrico com um diâmetro de 40 mm, de modo que a sua superfície de fundo cobre completamente a área de soldagem. Nota: Uma forma diferente de sonotrodo pode ser utilizado, mas a sua superfície inferior não deve ser menor do que a área da soldadura. </li><li> Posição e fixar espécimes e diretor de energia no gabarito de solda (ver figura 1). <ol><li> Anexar um director de energia fixa para o espécime inferior com fita adesiva de forma a cobrir uma área ligeiramente maior do que a área a ser soldada (12,7 mm x 25,4 mm). </li><li> Colocar a amostra de fundo para o gabarito e prenda-a apertando o parafuso superior. </li><li> Tape o outra extremidade do director de energia para a base da configuração de modo que ele permanece no lugar durante o processo. </li><li> Colocar a amostra superior no grampo, alinhá-lo e apertar o parafuso superior. </li><li> Posicione o grampo para a amostra superior voltada para a plataforma deslizante e aperte os dois parafusos. </li><li> Antes de prosseguir, aperte os quatro parafusos uma vez mminério. </li></ol></li><li> Determinar a duração óptima da fase de vibração com base no deslocamento do sonotrodo para alcançar a maior resistência de solda, tal como descrito nos passos 2.5.1 a 2.5.8. Nota: Uma duração óptima da fase de vibração é determinada para cada combinação desejada da força de soldadura e amplitude de vibração. <ol><li> Definir o soldador ultra-som para diferencial modo de controle de deslocamento. </li><li> Entrada de soldagem de força e amplitude de vibração para o soldador ultra-sons (por exemplo, 300 N e 86,2 mm). Nota: Para este soldador de ultra-sons, 86,2 uM corresponde à amplitude de vibração de pico-a-pico. Nas definições da máquina, que é expresso como metade deste valor, 43,1 uM. </li><li> Entrada o deslocamento sonotrodo, ou curso, no final da fase de vibração como um valor igual à espessura inicial do director de energia (por exemplo, 0,25 mm). </li><li> força de entrada de solidificação e tempo para o soldador ultra-sons (por exemplo, 1.000N e 4000 mseg). </li><li> Quando estiver pronto, colocar fones de ouvido com isolamento acústico e iniciar o processo de soldagem ultra-sônica. </li><li> Após a conclusão do processo, tomar nota dos seguintes parâmetros de saída: distância de solda, potência máxima, o tempo de vibração e energia. Remover o cupão a partir da configuração de soldagem e escrever seu número de identificação em ambas as extremidades com um marcador de tinta. </li><li> Exportar os dados de soldagem (alimentação e deslocamento do sonotrodo) para uma planilha e traçar o poder e deslocamento contra curvas de tempo durante a fase do processo de vibração. Nota: A curva de deslocamento deve traçar o deslocamento para baixo do sonotrodo relação à sua posição no início da fase de vibração. </li><li> Identificar o deslocamento no meio do planalto de alimentação (fase 4) como mostrado na Figura 2 (neste caso, 0,10 mm). Nota: Este valor de deslocamento particular é o curso óptimo que controla a duração da fase de vibração e vontadeser utilizado em todos os soldadura subsequente para a mesma força de soldadura e de amplitude. </li></ol></li></ol><img alt="Figura 2" src="/files/ftp_upload/53592/53592fig2.jpg" /> Figura 2. Energia (preto) e deslocamento curvas (cinza) para o processo de soldagem ultra-sônica indicando valor de viagem ideal. A fase da soldagem ultra-sônica da vibração pode ser dividido em 5 etapas. valor viagens Optimum está localizado dentro estágio 4. Estudo de Caso: fibra de carbono reforçada substratos polieterimida -PEI, diretor de energia PEI plana 0,25 mm de espessura, 300 N Força de soldadura, 86,2 mm amplitude de oscilação, 0,25 mm de curso. (Reproduzido de referência 4 com permissão de Elsevier.) <a href="https://www.jove.com/files/ftp_upload/53592/53592fig2large.jpg" target="_blank">Por favor, clique aqui para ver uma versão maior desta figura.</a> <ol start="6"><li> cupons de solda no valor de viagem ideal para a dada força de soldagem e combinaçã amplituden. <ol><li> Repita os passos 2.1 a 2.5.6 para cada soldadura. Na etapa 2.5.3, utilize o curso óptimo determinado na etapa 2.5.8 para a força de solda correspondente e combinação de amplitude. Nota: Todos os testes da ELA sejam efectuados segundo ASTM D 1002 em uma máquina universal de ensaios com uma velocidade de 1,3 mm / min. </li></ol></li></ol> 3. única volta Resistência ao cisalhamento (LSS) Testes de cupons Soldadas <ol><li> Meça e tome nota da largura da sobreposição para cada cupão soldada. </li><li> Ligue a máquina universal de ensaios e abrir o procedimento de teste para LSS no computador. </li><li> Na interface de teste, entrar o número da amostra e as dimensões da sobreposição. Definir a força a 0 e a separação aderência-à-aperto à sua posição inicial (por exemplo, 60 mm). </li><li> Posicionar a amostra nas garras da máquina de ensaios, como mostrado na Figura 3. </li></ol><img alt="Figura 3" src = &quot;/ files / ftp_upload / 53592 / 53592fig3.jpg&quot; /&gt; Figura 3. Representação esquemática da fixação na / Roell 250 kN máquina universal de ensaios Zwick (não está à escala). O deslocamento do deslocamento entre as garras superior e inferior permite o alinhamento da direcção da carga com a linha central da solda para minimizar a flexão durante o cisalhamento teste de força. <a href="https://www.jove.com/files/ftp_upload/53592/53592fig3large.jpg" target="_blank">por favor clique aqui para ver uma versão maior desta figura.</a> <ol start="5"><li> Iniciar o procedimento de teste a partir do computador clicando no botão &quot;Iniciar&quot;. </li><li> Após a amostra quebra, removê-lo das garras e fixe ambas as partes em conjunto com fita adesiva. </li><li> Repita os passos de 3,3-3,6 para todas as outras amostras. </li><li> Quando os ensaios são concluídos, exportar os dados para uma folha de cálculo e de calcular o valor médio de ELA, de acordo com o procedimento descrito na norma, para cada força de soldadura e combinação de amplitude. </li></ol>

<ol>
	<li>Yousefpour, A., Hojjati, M., Immarigeon, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fusion+bonding/welding+of+thermoplastic+composites.">Fusion bonding/welding of thermoplastic composites.</a> J Thermoplast Compos. 17, 303-341 (2004).</li><li>Villegas, I. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+monitoring+of+ultrasonic+welding+of+thermoplastic+composites+through+power+and+displacement+data.">In situ monitoring of ultrasonic welding of thermoplastic composites through power and displacement data.</a> J Thermoplast Compos. 28 (1), 66-85 (2015).</li><li>Benatar, A., Gutowski, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonic+welding+of+PEEK+Graphite+APC-2+composites.">Ultrasonic welding of PEEK Graphite APC-2 composites.</a> Polym Eng Sci. 29 (23), 1705-1721 (1989).</li><li>Villegas, I. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strength+development+versus+process+data+in+ultrasonic+welding+of+thermoplastic+composites+with+flat+energy+directors+and+its+application+to+the+definition+of+optimum+processing+parameters.">Strength development versus process data in ultrasonic welding of thermoplastic composites with flat energy directors and its application to the definition of optimum processing parameters.</a> Compos Part A-Appl S. 65, 27-37 (2014).</li><li>Lu, H. M., Benatar, A., He, F. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequential+ultrasonic+welding+of+PEEK/graphite+composite+plates.">Sequential ultrasonic welding of PEEK/graphite composite plates.</a> Proceedings of the ANTEC'91 Conference. , 2523-2526 (1991).</li><li>Potente, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonic+welding+-+principles+&amp;+theory.">Ultrasonic welding - principles &amp; theory.</a> Mater Design. 5, 228-234 (1984).</li><li>Stavrov, D., Bersee, H. E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resistance+welding+of+thermoplastic+composites+-+an+overview.">Resistance welding of thermoplastic composites - an overview.</a> Compos Part A-Appl S. 36, 39-54 (2005).</li><li>Villegas, I. F., Valle-Grande, B., Bersee, H. E. N., Benedictus, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparative+evaluation+between+flat+and+traditional+energy+directors+for+ultrasonic+welding+of+CF/PPS+thermoplastic+composites.">A comparative evaluation between flat and traditional energy directors for ultrasonic welding of CF/PPS thermoplastic composites.</a> Compos Interface. , (2015).</li><li>Levy, A., Le Corre, S., Villegas, I. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modelling+the+heating+phenomena+in+ultrasonic+welding+of+thermoplastic+composites+with+flat+energy+directors.">Modelling the heating phenomena in ultrasonic welding of thermoplastic composites with flat energy directors.</a> J Mater Process Tech. , 1361-1371 (2014).</li><li>Shi, H., Villegas, I. F., Bersee, H. E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strength+and+failure+modes+in+resistance+welded+thermoplastic+composite+joints:+effect+of+fibre-matrix+adhesion+and+fibre+orientation.">Strength and failure modes in resistance welded thermoplastic composite joints: effect of fibre-matrix adhesion and fibre orientation.</a> Compos Part A-Appl S. 55, 1-10 (2013).</li><li>Villegas, I. F., Bersee, H. E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonic+welding+of+advanced+thermoplastic+composites.+An+investigation+on+energy-directing+surfaces.">Ultrasonic welding of advanced thermoplastic composites. An investigation on energy-directing surfaces.</a> Adv Polym Tech. 29 (2), 113-121 (2010).</li><li>Harras, B. K., Cole, C., Vu-Khanh, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+the+ultrasonic+welding+of+PEEK-carbon+composites.">Optimization of the ultrasonic welding of PEEK-carbon composites.</a> J Reinf Plast Comp. 15 (2), 174-182 (1996).</li></ol>

The authors declare that they have no competing financial interest.

Os resultados apresentados na seção anterior indicam a adequação do método simples proposto neste trabalho para a soldagem ultra-sônica de compósitos cupons sobreposição simples termoplásticos para fins de teste mecânico. Os parágrafos seguintes discutem como os resultados validam os três principais pilares do método, ou seja, o uso de administração de energia soltos planas, uso de feedback do processo para definir a melhor duração da vibração e uso de controle de deslocamento, bem ...

Os materiais compósitos termoplásticos (TPC) tem a capacidade de ser soldado, o que contribui para a sua fabricação rentável. Soldadura requer aquecimento local sob pressão para amolecer ou fundir a resina termoplástica das superfícies de união e para permitir o contacto íntimo e subsequente inter-difusão de cadeias de polímeros termoplásticos em toda a interface de soldadura. Uma vez inter-difusão molecular é alcançado, o arrefecimento sob pressão consolida a junta soldada. Várias técnicas de soldagem são aplicáveis ​​aos compósitos termoplásticos que diferem principalmente na fonte de calor 1, no entanto, o principal mecanismo de &quot;adesão&quot;, isto é, o entrelaçamento molecular, permanece inalterada. soldadura ultra-sónica oferece tempos muito curtos de soldadura (na ordem de alguns segundos), a facilidade de automatização e que é praticamente independente do tipo de reforço nos substratos compósitos termoplásticos. Além disso, oferece a possibilidade de monitoramento in situ 2,3 </sup&gt;, Que pode ser usado no controle de qualidade de linha ou para a definição rápida de janelas de processamento 4. Soldagem ultra-sônica de compósitos termoplásticos é principalmente um processo de soldadura por pontos, soldadura bem sucedida no entanto de costuras mais longas através de soldadura ultra-sónica sequencial tem sido relatado na literatura 5. Em oposição à resistência à indução ou de soldadura, soldadura ultra-sónica não foi aplicado industrialmente para juntas estruturais entre as partes compósitas termoplásticas até agora. No entanto, um esforço significativo está sendo dedicada a promover o desenvolvimento de soldagem ultra-sônica estrutural dos compósitos termoplásticos para aplicações de aeronaves. Na soldadura ultra-sónica, as partes a serem juntas são submetidas a uma combinação de força estática e de alta frequência, vibrações mecânicas de baixa amplitude transversal à interface de soldadura, o que resulta na geração de calor através da superfície de aquecimento e viscoelástico. aquecimento preferencial na interface da soldadura é promovidaatravés da utilização de protuberâncias de resina sobre as superfícies a serem soldadas que passam por maior estirpe cíclico, e aquecimento, assim, maior viscoelástico, que os substratos 6. Força e vibração são exercida sobre as peças a serem soldadas por meio de um sonotrodo ligado a uma prensa e um trem de ultra-sónico que consiste de piezo eléctrico e conversor de reforço. Dependendo da distância entre o ponto em que os contactos sonotrodo a peça a ser unida e a interface de soldadura, uma distinção pode ser feita entre de campo próximo e de campo distante soldadura ultra-sónica. De campo próximo de soldadura (menos de 6 mm entre sonotrodo e interface de soldadura) é aplicável a uma ampla gama de materiais, enquanto a aplicabilidade de soldadura de campo distante a um material termoplástico específico é muito dependente da capacidade do material para conduzir as ondas sonoras 6 . O processo de soldadura ultra-sónica pode ser dividida em três fases principais. Em primeiro lugar, uma fase de força build-up, durante o qual o sonotroaumenta gradualmente de a força sobre as peças a soldar até uma certa força de gatilho for atingido. Sem vibração é aplicada durante esta fase. Em segundo lugar, uma fase de vibração, a qual começa quando a força de gatilho for atingido. Nesta fase, o sonotrodo vibra na amplitude prescrita para uma certa quantidade de tempo, gerando o calor necessário para o processo de soldagem. Controlado por microprocessador soldadores ultra-sons proporcionam várias opções para controlar a duração da fase de vibração, entre eles o tempo (ou seja, o controlo directo), ou o deslocamento de energia (controlo indirecto). A força aplicada durante esta fase, isto é, a força de soldadura, pode ser mantida constante e igual à força de disparo ou pode ser gradualmente variada durante a aplicação da vibração. Em terceiro lugar, uma fase de solidificação, durante o qual as peças soldadas são arrefecidos à temperatura ambiente sob uma certa força de solidificação de uma certa quantidade de tempo. Sem vibração é aplicada durante esta última fase. fo soldagemRCE, amplitude de vibração, frequência de vibração e duração da fase de vibração (directa ou indirectamente controlada por meio de energia ou deslocamento) são os parâmetros de soldagem que controlam a geração de calor. Força, amplitude e duração são parâmetros definidos pelo usuário, enquanto que a frequência é fixado para cada soldador ultra-sônica. força de solidificação e tempo de solidificação, também parâmetros de soldadura, não se intervir no processo de aquecimento, mas afectar a consolidação e, em conjunto com o resto dos parâmetros, a qualidade final das juntas soldadas. Este trabalho apresenta um método simples da novela para near-field soldagem ultra-sônica de cupons TPC individuais numa única configuração de volta para a subsequente, tesoura mecânica única volta (LSS), o teste seguinte ASTM (American Society for Testing and Materials) D 1002 standard. Os testes mecânicos dos cupões soldadas permite determinar a força de corte aparente volta das articulações, o que é uma das propriedades mais commapenas utilizado para quantificar a força de compósitos termoplásticos juntas soldadas 7. O método de soldagem descrito neste documento é baseado em três pilares principais. Em primeiro lugar, directores de energia plana soltos são usados ​​para geração de calor preferencial na interface juntar 8,9 durante o processo de soldagem. Em segundo lugar, o tratamento dos dados fornecidos pelo soldador de ultra-sons é usado para definir rapidamente o tempo óptimo da fase de vibração para uma força específica / combinação amplitude de 2,4. Em terceiro lugar, a duração da fase de vibração é controlada indirectamente por meio do deslocamento do sonotrodo, de modo a garantir uma qualidade consistente das juntas soldadas 4. Este método de soldagem oferece as seguintes novidades principais e vantagens com relação a procedimentos de soldagem state-of-the-art para compósitos termoplásticos: (a) preparação de amostras simplificado habilitado pelo uso de administração de energia planas soltos em vez de directores de energia moldados tradicionais 3, e (b) e c rápidodefinição ost-eficiente dos parâmetros de processamento com base no monitoramento de processos in-situ, em oposição às abordagens de tentativa e erro comuns. Embora o método descrito neste trabalho é voltado para a obtenção de uma geometria muito específica e simples de solda que pode servir de base para definir um procedimento para a soldagem de peças reais. A principal diferença, nesse caso, resulta de fluxo restrita do diretor de energia em oposição ao fluxo irrestrito nas quatro bordas da sobreposição de cupons de sobreposição simples.

<table border="0" cellpadding="0" cellspacing="0" width="1179">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Material/Reagent</td>
			<td style="width:308px;"></td>
			<td style="width:199px;"></td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:311px;">Cetex&#174; carbon fiber / polyetherimide (CF/PEI) 5 harness satin prepreg</td>
			<td style="width:308px;">TenCate Advanced Composites (www.tencate.com)</td>
			<td style="width:199px;">Contact vendor</td>
			<td style="width:363px;">Material used in this study for the specimens.</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:311px;">PFQD solvent degreaser</td>
			<td style="width:308px;">PT Technologies Europe (now Socomore - www.socomore.com)</td>
			<td style="width:199px;">Contact vendor</td>
			<td style="width:363px;">Solvent degreaser for cleaning the specimens and energy directors.</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:311px;">Cotton cloths</td>
			<td style="width:308px;">-</td>
			<td style="width:199px;">-</td>
			<td style="width:363px;">For general cleaning purposes. No specific vendor was used.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:311px;">0.25 mm PEI film</td>
			<td style="width:308px;">TenCate Advanced Composites (www.tencate.com)</td>
			<td style="width:199px;">Contact vendor</td>
			<td style="width:363px;">Thin film used as energy director.</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:311px;">Adhesive tape</td>
			<td style="width:308px;">Airtech Advanced Materials Group (www.airtechintl.com)</td>
			<td style="width:199px;">1&#34; x 72 yds MFG # 327402 Contact vendor for catalog number</td>
			<td style="width:363px;">Used to attach energy director to bottom sample for ultrasonic welding.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Name</td>
			<td style="width:308px;">Company</td>
			<td style="width:199px;">Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Equipment</td>
			<td style="width:308px;"></td>
			<td style="width:199px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:311px;">V&#246;tsch oven</td>
			<td style="width:308px;">V&#246;tsch Industrietechnik (www.voetsch-ovens.com)</td>
			<td style="width:199px;">VTU 60/60 - Contact vendor for specific catalog number</td>
			<td style="width:363px;">Oven used to dry PEI film (energy directors) and PEI specimens before welding.</td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:311px;">Rinco Dynamic 3000 ultrasonic welder</td>
			<td style="width:308px;">Aeson BV (www.aeson.nl/en/)</td>
			<td style="width:199px;">Contact vendor</td>
			<td style="width:363px;">20 kHz ultrasonic welding machine used for the welding experiments. Several sonotrode sizes available. Contact vendor for details. ACUCapture software included.</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:311px;">Zwick/Roell universal testing machine</td>
			<td style="width:308px;">Zwick (www.zwick.com)</td>
			<td style="width:199px;">Z250 - Contact vendor for specific catalog number</td>
			<td style="width:363px;">Universal testing machine with maximum load of 250 kN used for single lap shear strength measurements.</td>
		</tr>
	</tbody>
</table>

ultrasonic welding of thermoplastic composite coupons for mechanical characterization of welded joints through single lap shear testing

This paper presents a novel straightforward method for ultrasonic welding of thermoplastic-composite coupons in optimum processing conditions. The ultrasonic welding process described in this paper is based on three main pillars. Firstly, flat energy directors are used for preferential heat generation at the joining interface during the welding process. A flat energy director is a neat thermoplastic resin film that is placed between the parts to be joined prior to the welding process and heats up preferentially owing to its lower compressive stiffness relative to the composite substrates. Consequently, flat energy directors provide a simple solution that does not require molding of resin protrusions on the surfaces of the composite substrates, as opposed to ultrasonic welding of unreinforced plastics. Secondly, the process data provided by the ultrasonic welder is used to rapidly define the optimum welding parameters for any thermoplastic composite material combination. Thirdly, displacement control is used in the welding process to ensure consistent quality of the welded joints. According to this method, thermoplastic-composite flat coupons are individually welded in a single lap configuration. Mechanical testing of the welded coupons allows determining the apparent lap shear strength of the joints, which is one of the properties most commonly used to quantify the strength of thermoplastic composite welded joints.

amostras de fibra de carbono reforçada polyetherimide (CF / PEI) foram soldados seguindo o método descrito neste artigo. As amostras foram obtidas a partir de um laminado composto feito de cinco arnês CF tecido de cetim / PEI, com (0/90) 3S empilhamento sequência e 1,92 mm de espessura nominal. As amostras foram cortadas a partir deste laminado de modo que a orientação principal aparente das fibras era paralelo ao seu lado mais comprido. foram utilizados diretores planos...

Watch this Scientific Journal Video about Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing at JoVE.com

Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing

A straightforward procedure for ultrasonic welding of thermoplastic composite coupons for basic mechanical testing is described. Key characteristics of this ultrasonic welding process are the use of flat energy directors for simplified process preparation and the use of process data for the fast definition of optimum processing conditions.

Ultrasonic Welding de cupons termoplástica composta de Mecânica Caracterização de Juntas Soldadas através Individual Sobreposição Testing

This paper presents a novel straightforward method for ultrasonic welding of thermoplastic-composite coupons in optimum processing conditions. The ...

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11.5K visualizações.  Delft University of Technology. A straightforward procedure for ultrasonic welding of thermoplastic composite coupons for basic mechanical testing is described. Key characteristics of this ultrasonic welding process are the use of flat energy directors for simplified process preparation and the use of process data for the fast definition of optimum processing conditions.

Vídeo: Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of the effective friction coefficient between two sliding surfaces. This property enables adaptive systems that modify their frictional state and associated dynamic response as the operating conditions change. Surface wear can also be reduced through ultrasonic lubrication. We developed a protocol to investigate the dependence of friction force reduction and wear reduction on the linear sliding velocity between ultrasonically lubricated surfaces. A pin-on-disc tribometer was built which differs from commercial units in that a piezoelectric stack is used to vibrate the pin at 22 kHz normal to the rotating disc surface. Friction and wear metrics including effective friction force, volume loss, and surface roughness are measured without and with ultrasonic vibrations at a constant pressure of 1 to 4 MPa and three different sliding velocities: 20.3, 40.6, and 87 mm/sec. An optical profilometer is utilized to characterize the wear surfaces. The effective friction force is reduced by 62% at 20.3 mm/sec. Consistently with existing theories for ultrasonic lubrication, the percent reduction in friction force diminishes with increasing speed, down to 29% friction force reduction at 87 mm/sec. Wear reduction remains essentially constant (49%) at the three speeds considered.

We present a protocol for using a piezoelectrically-assisted tribometer and optical profilometer to investigate the dependence of ultrasonic wear and friction reduction on linear velocity, contact pressure, and surface properties.

Experimentos em Ultrasonic Lubrificação Usando um tribômetro piezoelectricamente-assistida e Profilometer Optical

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at ...

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Testing of Nanoparticle Release from a Composite Containing Nanomaterial Using a Chamber System

With the rapid development of nanotechnology as one of the most important technologies in the 21st century, interest in the safety of consumer products containing nanomaterials is also increasing. Evaluating the nanomaterial release from products containing nanomaterials is a crucial step in assessing the safety of these products, and has resulted in several international efforts to develop consistent and reliable technologies for standardizing the evaluation of nanomaterial release. In this study, the release of nanomaterials from products containing nanomaterials is evaluated using a chamber system that includes a condensation particle counter, optical particle counter, and sampling ports to collect filter samples for electron microscopy analysis. The proposed chamber system is tested using an abrasor and disc-type nanocomposite material specimens to determine whether the nanomaterial release is repeatable and consistent within an acceptable range. The test results indicate that the total number of particles in each test is within 20% from the average after several trials. The release trends are similar and they show very good repeatability. Therefore, the proposed chamber system can be effectively used for nanomaterial release testing of products containing nanomaterials.

Nanoparticle release is tested using a chamber system that includes a condensation particle counter, an optical particle counter and sampling ports to collect filter samples for microscopy analysis. The proposed chamber system can be effectively used for nanomaterial release testing with a repeatable and consistent data range.

Ensaios de nanopartículas de lançamento a partir de um composto que contém Nanomaterial Usando um sistema de câmara

With the rapid development of nanotechnology as one of the most important technologies in the 21st century, interest in the safety of consumer products ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

Challenges in Rheological Characterization of Highly Concentrated Suspensions &amp;#8212; A Case Study for Screen-printing Silver Pastes

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

Desafios na reológico Caracterização de suspensões altamente concentrado - um estudo de caso para-impressão da tela de prata Cola

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

A Novel Biaxial Testing Apparatus for the Determination of Forming Limit under Hot Stamping Conditions

The hot stamping and cold die quenching process is increasingly used to form complex shaped structural components of sheet metals. Conventional experimental approaches, such as out-of-plane and in-plane tests, are not applicable to the determination of forming limits when heating and rapid cooling processes are introduced prior to forming for tests conducted under hot stamping conditions. A novel in-plane biaxial testing system was designed and used for the determination of forming limits of sheet metals at various strain paths, temperatures, and strain rates after heating and cooling processes in a resistance heating uniaxial testing machine. The core part of the biaxial testing system is a biaxial apparatus, which transfers a uniaxial force provided by the uniaxial testing machine to a biaxial force. One type of cruciform specimen was designed and verified for the formability test of aluminum alloy 6082 using the proposed biaxial testing system. The digital image correlation (DIC) system with a high-speed camera was used for taking strain measurements of a specimen during a deformation. The aim of proposing this biaxial testing system is to enable the forming limits of an alloy to be determined at various temperatures and strain rates under hot stamping conditions.

This protocol proposes a novel biaxial testing system used on a resistance heating uniaxial tensile test machine in order to determine the forming limit diagram (FLD) of sheet metals under hot stamping conditions.

Um novo aparelho Biaxial Teste para a Determinação do limite de conformação sob Hot Stamping Condições

The hot stamping and cold die quenching process is increasingly used to form complex shaped structural components of sheet metals. Conventional ...

Experimental Implementation of a New Composite Fabrication Method: Exposing Bare Fibers on the Composite Surface by the Soft Layer Method

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional component that should have high electrical conductivity, high mechanical properties, and high productivity.
In this regard, a carbon fiber/epoxy resin composite can be an ideal material to replace the conventional graphite bipolar plate, which often leads to the catastrophic failure of the entire system because of its inherent brittleness. Though the carbon/epoxy composite has high mechanical properties and is easy to manufacture, the electrical conductivity in the through-thickness direction is poor because of the resin-rich layer that forms on its surface. Therefore, an expanded graphite coating was adopted to solve the electrical conductivity issue. However, the expanded graphite coating not only increases the manufacturing costs but also has poor mechanical properties.
In this study, a method to expose fibers on the composite surface is demonstrated. There are currently many methods that can expose fibers by surface treatment after the fabrication of the composite. This new method, however, does not require surface treatment because the fibers are exposed during the manufacture of the composite. By exposing bare carbon fibers on the surface, the electrical conductivity and mechanical strength of the composite are increased drastically.

A protocol to expose bare fibers on the composite surface by eliminating resin rich area is presented. The fibers are exposed during fabrication of the composites, not by the post surface treatment. The exposed carbon composites exhibit high electrical conductivity in the through-thickness direction and high mechanical property.

Implementação experimental de um novo método de fabricação de compósitos: expondo desencapadas fibras na superfície composta pelo método suave camada

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional ...

Ultrasonic Fatigue Testing in the Tension-Compression Mode

Ultrasonic fatigue testing is one of a few methods which allow investigating fatigue properties in the ultra-high cycle region. The method is based on exposing the specimen to longitudinal vibrations on its resonance frequency close to 20 kHz. With use of this method, it is possible to significantly decrease the time required for the test, when compared to conventional testing devices usually working at frequencies under 200 Hz. It is also used to simulate loading of material during operation in high speed conditions, such as those experienced by components of jet engines or car turbo pumps. It is necessary to operate only in the high and ultra-high cycle region, due to the possibility of extremely high deformation rates, which can have a significant influence on the test results. Specimen shape and dimensions have to be carefully selected and calculated to fulfill the resonance condition of the ultrasonic system; thus, it is not possible to test the full components or specimens of arbitrary shape. Before each test, it is necessary to harmonize the specimen with the frequency of the ultrasonic system to compensate for deviations of the real shape from the ideal one. It is not possible to run a test until a total fracture of the specimen, since the test is automatically terminated after initiation and propagation of the crack to a certain length, when the stiffness of the system changes enough to shift the system out of the resonance frequency. This manuscript describes the process of evaluation of materials' fatigue properties at high-frequency ultrasonic fatigue loading with use of mechanical resonance at a frequency close to 20 kHz. The protocol includes a detailed description of all steps required for a correct test, including specimen design, stress calculation, harmonizing with the resonance frequency, performing the test, and final static fracture.

A protocol for ultrasonic fatigue testing in the high and ultra-high cycle region in axial tension-compression loading mode.

Fadiga ultra-sônico de teste no modo de tensão-compressão

Ultrasonic fatigue testing is one of a few methods which allow investigating fatigue properties in the ultra-high cycle region. The method is based on ...

Magnet Assisted Composite Manufacturing: A Flexible New Technique for Achieving High Consolidation Pressure in Vacuum Bag/Lay-Up Processes

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed magnet assisted composite manufacturing (MACM) technique. In this technique, permanent magnets are utilized to apply a sufficiently high consolidation pressure during the curing stage. To enhance the intensity of the magnetic field, and thus, to increase the magnetic compaction pressure, the magnets are placed on a magnetic top plate. First, the entire procedure of preparing the composite lay-up on a magnetic bottom steel plate using the conventional wet lay-up vacuum bag process is described. Second, placement of a set of Neodymium-Iron-Boron permanent magnets, arranged in alternating polarity, on the vacuum bag is illustrated. Next, the experimental procedures to measure the magnetic compaction pressure and volume fractions of the composite constituents are presented. Finally, methods used to characterize microstructure and mechanical properties of composite laminates are discussed in detail. The results prove the effectiveness of the MACM method in improving the quality of wet lay-up vacuum bag laminates. This method does not require large capital investment for tooling or equipment and can also be used to consolidate geometrically complex composite parts by placing the magnets on a matching top mold positioned on the vacuum bag.

A new technique for applying consolidation pressure on the vacuum bag lay-up to fabricate composite laminates is described. The goal of this protocol is to develop a simple, cost-effective technique to improve the quality of laminates fabricated by the wet lay-up vacuum bag method.

Ímã assistida fabricação composta: Uma nova técnica flexível para alcançar a consolidação de alta pressão em vácuo processos de saco/Lay-Up

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed ...

Generating Lap Joints Via Friction Stir Spot Welding on DP780 Steel

Friction stir spot welding (FSSW), a derivative of friction stir welding (FSW), is a solid-state welding technique that was developed in 1991. An industry application was found in the automotive industry in 2003 for the aluminum alloy that was used in the rear doors of automobiles. Friction stir spot welding is mostly used in Al alloys to create lap joints. The benefits of friction stir spot welding include a nearly 80% melting temperature that lowers the thermal deformation welds without splashing compared to resistance spot welding. Friction stir spot welding includes 3 steps: plunging, stirring, and retraction. In the present study, other materials including high strength steel are also used in the friction stir welding method to create joints. DP780, whose traditional welding process involves the use of resistance spot welding, is one of several high strength steel materials used in the automotive industry. In this paper, DP780 was used for friction stir spot welding, and its microstructure and microhardness were measured. The microstructure data showed that there was a fusion zone with fine grain and a heat effect zone with island martensite. The microhardness results indicated that the center zone exhibited a greater degree of hardness compared with the base metal. All data indicated that the friction stir spot welding used in dual phase steel 780 can create a good lap joint. In the future, friction stir spot welding can be used in high-strength steel welding applied in industrial manufacturing processes.

Here, we present a friction stir spot welding (FSSW) protocol on dual phase 780 steel. A tool pin with high-speed rotation generates heat from friction to soften the material, and then, the pin plunges into 2 sheet joints to create the lap joint.

Gerando junções de regaço através da soldadura do ponto do stir da fricção no aço DP780

Friction stir spot welding (FSSW), a derivative of friction stir welding (FSW), is a solid-state welding technique that was developed in 1991. An industry ...

Cutting Procedures, Tensile Testing, and Ageing of Flexible Unidirectional Composite Laminates

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, where the yarns in each layer are oriented parallel to each other and held in place using binder resins and thin polymer films. The armor is constructed by stacking the unidirectional layers in different orientations. To date, only very preliminary work has been performed to characterize the ageing of the binder resins used in unidirectional laminates and the effects on their performance. For example, during the development of the conditioning protocol used in the National Institute of Justice Standard-0101.06, UD laminates showed visual signs of delamination and reductions in V50, which is the velocity at which half of the projectiles are expected to perforate the armor, after ageing. A better understanding of the material property changes in UD laminates is necessary to comprehend the long-term performance of armors constructed from these materials. There are no current standards recommended for mechanically interrogating unidirectional (UD) laminate materials. This study explores methods and best practices for accurately testing the mechanical properties of these materials and proposes a new test methodology for these materials. Best practices for ageing these materials are also described.

The goal of the study was to develop protocols to prepare consistent specimens for accurate mechanical testing of high-strength aramid or ultra-high-molar-mass polyethylene-based flexible unidirectional composite laminate materials and to describe protocols for performing artificial ageing on these materials.

Procedimentos de corte, testes de tração e envelhecimento de laminados unidirecionais flexíveis compósitos

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, ...

Operation of the Collaborative Composite Manufacturing (CCM) System

The automated tape placement and the automated fiber placement (AFP) machines provide a safer working environment and reduce the labor intensity of workers than the traditional manual fiber placement does. Thus, the production accuracy, repeatability and efficiency of composite manufacturing are significantly improved. However, the current AFP systems can only produce the composite components with large open surface or simple revolution parts, which cannot meet the growing interest in small complex or closed structures from industry.
In this research, by employing a 1-degree of freedom (DoF) rotational stage, a 6-RSS parallel robot, and a 6-DoF serial robot, the dexterity of the AFP system can be significantly improved for manufacturing complex composite parts. The rotational stage mounted on the parallel robot is utilized to hold the mandrel and the serial robot carries the placement head to mimic two human hands that have enough dexterity to lay the fiber to the mandrel with complex contour.
Although the CCM system increases the flexibility of composite manufacturing, it is quite time-consuming or even impossible to generate the feasible off-line path, which ensures uniform lay-up of subsequent fibers considering the constraints like singularities, collisions between the fiber placement head and mandrel, smooth fiber direction change and keeping the fiber placement head along the norm of the part&#39;s surface, etc. Moreover, due to the existing positioning error of the robots, the on-line path correction is needed. Therefore, the on-line pose correction algorithm is proposed to correct the paths of both parallel and serial robots, and to keep the relative path between the two robots unchanged through the visual feedback when the constraint or singularity problems in the off-line path planning occur. The experimental results demonstrate the designed CCM system can fulfill the movement needed for manufacturing a composite structure with Y-shape.

Operation of the Collaborative Composite Manufacturing CCM System

A collaborative composite manufacturing system is developed for robotic lay-up of composite laminates using the prepreg tape. The proposed system allows the production of composite laminates with high levels of geometrical complexity. The issues in the path planning, coordination of the robots and control are addressed in the proposed method.

Operação do sistema colaborativo de manufatura composta (CCM)

The automated tape placement and the automated fiber placement (AFP) machines provide a safer working environment and reduce the labor intensity of ...