感謝する著者、中国国家から自然科学基礎 (許可番号 51578208)、河北地方自然科学財団 (グラント号金融サポートE2017202030 と E2014202178 のような)、およびキーの大学科学のプロジェクトおよび河北省 (グラント号の技術研究ZD2015028)。

1. ソレノイド磁場セットアップ
注: 磁場は、空洞のソレノイドによって生成されます。セットアップは、ポリブチレンテレフタ レート (PBT) ボード ソレノイド スケルトン 4 - 6 エナメルの層は銅電線し、保護 (図 1) のためのプラスチック絶縁層巻きコイルです。Dc コイルを接続した後、コイル内の電流は固定方向と強度定数の磁気誘導ソレノイド チャンバー内の均一な電磁界を作成します。モルタルに鋼繊維を合わせ、ASFRC 標本の作製に磁場を使用します。本研究で我々 は 150 × 150 × 550 mm プリズム試料室サイズ 250 × 250 × 750 mm のソレノイドを使用して準備。
<ol><li>ソレノイドの電流を磁気誘導強度を関連付けます。<ol>
<li>Dc ソレノイドを接続し、0 から現在 10 A 1 A. 測定して記録テスラ メーターを用いた電磁室における磁気誘導強度のステップ長と適用します。</li>
		<li>ソレノイドの必要電流を確認後の手順で使用される磁気誘導電流強度曲線 (図 2) をプロットします。 注意: 慎重に手順を電気的安全性を電源と電力に関連するすべての操作手順でソレノイドを接続するとき。</li>
	</ol>
</li>
</ol>2. フレッシュ モルタルの施工性
<ol><li>3 つの準備とモルタル混合繊維量分数 0.8%、1.2% と 2.0% の鋼をそれぞれ (表 1)。3 つのミックスは、0.42:1:2 の比を砂にセメントを水と同じマトリックス組成を持っています。混合比によるとセメントの 0.5 kg、砂、1.0 kg と 0.21 kg 加工性テストのための水の重量を量る。</li>
	<li>まず、モルタル ミキサーに水を追加します。セメントを加えます。ミックスは、水とセメントの 30 s。別の 30 のミックス s、この 30 の中に混合の s は、ミキサーに砂を徐々 に追加。別の 60 のミックス s。</li>
	<li>モルタル (JGJ/T70-2009)19階パフォーマンスのテスト メソッドの中国の標準に続く沈降深度計を用いた混合物の沈降深さをテストします。</li>
	<li>2.2 と 2.3、シンクの深さに 50 〜 100 ミリメートルの範囲内になるまで、高性能減水剤の投与量を調整する手順を繰り返します。目的の作業を生成する高性能減水剤の投与量を記録し、表 1に調合の一部としてそれを補います。また施工性が達成された後は、フレッシュ モルタルの比重をテストします。上記の検査からポリカルボン酸系高性能減水剤の最適投与量は 0.10% (セメント質量比) とモルタルの比重は 2186 kg/m3。</li>
	<li>同軸回転モルタル レオメータ (図 3) を用いたフレッシュ モルタルの粘性をテストします。レオメータ、20 ° C でサンプル容器の温度を維持することができます水のお風呂<ol>
<li>サンプル容器に混合前の 5 分以内モルタルの 300 mL を入れます。</li>
		<li>粘度試験を開始します。コンテナーで、モルタルにプローブがだんだんし、コンテナーが回転を開始します。フレッシュ モルタル回転容器内の移動、せん断力がプローブに適用されます。過程で、レオメータ レコードせん断応力とせん断速度し、ずり速度、剪断応力の曲線をプロットします。曲線の傾きは、モルタル20,21の粘度です。この調査では、テストからフレッシュ モルタルの粘度は 0.82 Pas です。</li>
	</ol>
</li>
</ol>3. 試料作製
<ol><li>磁場の磁気誘導強度と、ソレノイドの電流を決定します。<ol>
<li>2.5.2、ステップで決定したセメント モルタルの粘度を使用して計算式 (1) を用いたセメント モルタルにおける鋼繊維を揃えるために必要な磁場の磁気誘導強度:13 <img alt="Equation 1" src="/files/ftp_upload/56307/56307eq1v2.jpg">(1) Bが磁気誘導強度、 ηはフレッシュ モルタルの粘性、 lfは鋼繊維の長さ、 mは個々 の鋼繊維の質量、 rfはスチール繊維、 μ の半径鋼繊維の透磁率、 μ0は真空の透磁率、Δtが時間間隔ありα(t + Δt) 次の時間間隔で角加速度は。粘度と鋼繊維のテストで使用されるパラメーターによると必要な磁気誘導強度は 9.83 山</li>
		<li>図 2または式 (2) によると十分な磁気誘導強度を作成するために必要なソレノイドの電流を決定する:14 <img alt="Equation 2" src="/files/ftp_upload/56307/56307eq2v2.jpg">(2) 必要な電流は、 Nはソレノイド巻き数、 Lはソレノイドの長さ。 式 (2) を使用すると、必要な電流は 8.3 A、図 2からは約 8.5 a.</li>
	</ol>
</li>
	<li>ASFRC 標本を作製します。<ol>
<li>15 L モルタル ミキサーを使用すると、モルタルを混ぜます。各バッチのためによると、表 1に示した調合モルタルの 7.5 L をミックスします。表 1 は、A V とfA が、鋼繊維が規則正しく並んだ、Vfは鋼繊維体積率を示します ASFRC ミックスを表します。したがって、SFRC ミックス示されます、比較のため R V とfR が鋼繊維がランダムに分布していることを示します。SFRC ミックスは表 1に記載されていないが ASFRC と同じ比率です。</li>
		<li>原材料の重量を量るし、鋼繊維補強モルタルのルーチンの手順を次を混ぜます。</li>
		<li>明確なサイズの 150 × 150 × 550 mm. とプラスチック金型にモルタルを注ぐ作業性を失うことを避けるために混合後速やかに試料をキャストしました。セメントと水との接触からの 1 つの ASFRC プリズムをキャスト約 25 分します。</li>
		<li>圧縮テーブルの上に金型を移動し、圧縮テーブル 30 s. 追加のため、金型は完全に満ちていることを確認するため必要に応じてより多くの乳鉢を切り替えます。</li>
		<li>ソレノイドの商工会議所に金型を入れます。</li>
		<li>ソレノイドおよび 50 の圧縮テーブルのスイッチ s。 注: 普通コンクリートの合理的な圧縮に周りが 60-120 s。このテストでは、この範囲内で総圧縮時間を制御しようが。もはや圧縮時間は、鋼繊維; のアライメントを改善可能性があります。ただし、それは圧縮とその結果 (沈没スチール繊維と粗骨材がある場合) の分離を引き起こすかもしれません。圧縮時間は、鋼繊維と非連結コンクリートの位置合わせが不正確で可能性があります。</li>
		<li>圧縮テーブルをオフにします。</li>
		<li>スイッチ、ソレノイドを切る圧縮テーブルが完全に停止した後。</li>
		<li>優しくソレノイドから金型を取り出して、こてでモルタルの上面を滑らかに。上面に近い鋼繊維を妨害しません。</li>
	</ol>
</li>
	<li>各ミックス (次の手順 3.2.2-3.2.9) 電磁治療の 3 つの標本と (次の手順 3.2.2-3.2.4 と 3.2.9) 非電磁治療の 3 つの標本を準備します。非電磁処理試料作製、圧縮時間の合計は 80 s-電磁処理試料作製のと同じ。</li>
	<li>屋内と 24 h の金型では、標本をままにします。脱型し、霧部屋で標本を治す機械試験に使用されるまで。</li>
</ol>4. 3 点曲げ試験
<ol><li>28 日後養生室から試験片を取り出し、(A)、(B) をサポート、中間スパンのたわみ (C)、LVDT は、固定点 (D) (図 4) の読み込み位置をマークします。</li>
	<li>MTS 試験機の 3 点曲げ試験装置 (図 4) に標本を置き、供試体 (図 4) の各側面の LVDT ホルダーを使用して中間スパンに LVDT を修正します。</li>
	<li>Datalog、LVDT に接続します。試験機の制御 PC のデータの取得頻度を設定します。</li>
	<li>徐々 に上げて下をサポートして、載荷試験機のセル上に非常に近いが、供試体の上面に触れていない供試体を発生させます。</li>
	<li>初期読み込み、中間スパンのたわみ (LVDT) と変位 (ロードセル) 値はゼロします。</li>
	<li>テストを開始し、標本の読み込みと中間スパンのたわみの完全な履歴のレコードを 0.2 mm/分の速度で変位制御をもつ試料に 3 点曲げ荷重を適用します。</li>
	<li>負荷と供試体の変形を見る。ピーク値の後の変位が 30 mm より大きい、テストを停止します。通常、試料が割れているし、負荷が 1.0 未満 kN。</li>
	<li>すべての標本をテストする 4.1 4.7 の手順を繰り返します。</li>
</ol>5. 鋼繊維配向解析
<ol><li>骨折部に鋼繊維の数をカウントします。<ol>
<li>標本をひびの入ったセクションで 2 つの部分に分けます。</li>
		<li>測定し、セメント モルタル試験片の破断面の鋼繊維の向きを記録します。方向は、鋼繊維と供試体の軸間の角度です。向きを六つの角度範囲のいずれかに分類できます鋼繊維の向きを手動で測定が困難な不正確な測定を作り出すことができるので: 0 - 15 °、15-30 °、30 ~ 45 °、45-60 °、60-75 °、75-90 °。各グループの鋼繊維の数を記録し、式 (3) を用いた試験体の平均繊維配向効率因子を計算します。 <img alt="Equation 3" src="/files/ftp_upload/56307/56307eq3v2.jpg">(3) ηθは鋼繊維の平均方位効率係数、 lfは個々 の鋼繊維の長さ、 nはひび割れ部に鋼繊維の合計数とθは私です、鋼繊維と試料に印加される磁界の方向間の角度 (計算、角度範囲の中間の値は、各グループにおけるすべての鋼繊維に採用されて)。</li>
	</ol>
</li>
	<li>X 線トモグラフィー解析を実行します。<ol>
<li>各モルタル供試体から 75 mm キューブをカットします。</li>
		<li>X 線断層撮影システムを使用してキューブの x 線スキャンを実行します。テスト プラットフォームで試験片を置き、スキャンを開始します。供試体は徐々 に 360 ° を回転し、回転ステップごとに試料による x 線の減衰を記録します。コンピューター断層撮影システムでは、キューブの三次元デジタル構造を生成します。</li>
		<li>白と黒の二値化処理、デジタル キューブ構造における鋼繊維を識別します。鋼繊維の分布を記述する画像を取得します。</li>
		<li>画像解析によるすべての鋼繊維の座標を決定します。</li>
		<li>その座標によると各鋼繊維の方向を計算します。</li>
		<li>式 (3) を使用して繊維の配向の効率因子を計算します。</li>
	</ol>
</li>
</ol>

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著者が明らかに何もありません。

本研究で開発した電磁ソレノイド 250 × 250 × 750 mm を測定室には、フルサイズの構造要素を格納することはできません。商工会議所のサイズ設定、概念のアプリケーションに関する制限、本論文で提案されたプロトコルがフルサイズ セットアップ ASFRC 要素の製造のためのそれ以上の開発を刺激する、プレキャストの要素が特に。
鋼繊維の配置はフレッシュ モルタルの粘?...

コンクリートに鋼繊維を組み込むことは、脆性の固有の弱さを克服するためにコンクリート1の引張強さを改善する効果的な方法です。過去数十年の間に鋼繊維補強コンクリートは広く調査されフィールドで広く使用されます。鋼繊維補強コンクリートは、優れた耐ストレスクラッ キング性、引張強度、破壊靭性、破壊エネルギー等の面でコンクリート2鋼繊維補強コンクリート、鋼繊維でランダムに分散している、それによってあらゆる方向に繊維の補強効率を均一に分散させ。ただし、特定の荷重条件下でコンクリートの鋼繊維の一部だけに貢献構造要素の性能繊維の補強効率は彼らが原則と引張応力を整列することを必要とするため、構造体です。例えば、鋼繊維補強コンクリートの鋼繊維をランダムに分布を含むを使用してビーム鋼繊維のいくつかを準備するとき特にそれらは主引張応力の方向に平行はへの主要な貢献を作るそれらの効率を強化主引張応力の方向に対して垂直になるない効率の強化に貢献。したがって、鋼繊維コンクリートの引張応力の方向に合わせてアプローチを発見鋼繊維補強最高の効率を達成するために必要です。
繊維の実際の長さに引張応力の方向に沿って投影長さの比率として定義されている向きの効率因子通常鋼繊維3,4 の補強の有効性を示すため.この定義によると引張応力の方向に揃えて繊維の配向効率因子は 1.0;引張応力に垂直な繊維のそれは 0 です。傾斜ファイバー 0 から 1.0 まで向き効率因子があります。分析の結果、コンクリートにおけるランダム鋼繊維の配向効率因子は 0.500 0.167 に5,6 までの範囲では普通鋼繊維補強コンクリートのテストから 0.4054、.明らかに、すべての短い鋼繊維コンクリート中に並べ、引張応力と同じ向き、鋼繊維は最高の補強効率を持っている、標本は最適の引張挙動を持っています。
一直線に並べられた鋼繊維補強コンクリートを準備するいくつかの成功した試行は、1980 年代から行われてきました。1984 年、シェン7は鋳造中に鋼繊維補強セメント系複合材料 (SFRC) 梁の底層に電磁界を適用し、x 線検出解析鋼繊維が整列したも明らかにしました。1995 年にバイエル8とアーマン9磁場を用いたアライメントされた鋼繊維補強コンクリートの準備のためのアプローチ特許を取得しました。山本ら10では、主に鋳造方法によって影響を受けるし、一定の方向から型枠に流れるフレッシュ コンクリートを保つことによって一直線に並べられた鋼繊維補強コンクリートを取得しようとしたためにコンクリートの鋼繊維の方向と見なされます。徐11一定の方向から鋼繊維を噴霧することにより吹付けコンクリートの鋼繊維を配置しようとしました。ロトンドやウィーナー12遠心鋳造によって一直線に並べられた長い鋼繊維コンクリート製電柱を作るように努めた。これらの実験的研究では、ランダムに配置された鋼繊維補強コンクリートの大きな利点は、一直線に並べられた鋼繊維補強コンクリートを明らかにします。
最近、ミケルスら13 Muら14整列鋼繊維補強セメント系複合材料 (ASFRCs) 電磁フィールドを使用してグループを開発しました。これらの研究で様々 なソレノイドは、サイズの異なるモルタル試験体における鋼繊維を揃えるため一様磁場を提供するためになされました。ソレノイドは空洞、定義済みのサイズの標本を収容できる立方体です。ソレノイドを直流 (DC) に接続すると、チャンバー内にソレノイドの軸に揃えます一定の方向に一様な磁界が作成されます。電磁気学15の主義に従って磁界が回転し、モルタルで整列する強磁性ファイバーをドライブできます。モルタルの適切な施工はモルタルで回転する鋼繊維をできるようにするため重要です。高粘度低粘度は繊維の分離につながる可能性があります、モルタルに鋼繊維の配置が困難を引き起こす可能性があります。
本稿では、ASFRC 試験片の準備の詳細と、ASFRC、SFRC の曲げ特性をテストします。ASFRC、高い曲げ強度と SFRC より靱性が期待されます。したがって、ASFRC の引張応力に耐える SFRC 上利点がある可能性がある、かぶりコンクリート、舗装、等として使用される場合、耐割れ
骨折の試料を用いて曲げ試験後破断面を観察することにより検討する標本における鋼繊維の向きとスキャン利用 x 線トモグラフィー解析16,17の計算,18. ASFRCs、曲げ強度、靭性などの機械的性質の報告し、比較した非電磁治療 SFRCs の。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr >
			<td >Cement</td>
			<td >Tangshan Jidong Cement Co., Ltd.</td>
			<td >P&#215;O 42.5</td>
			<td >Oridnary Portland Cement</td>
		</tr>
		<tr >
			<td >Sand</td>
			<td ></td>
			<td >River sand</td>
			<td>Fineness modulus is 2.4</td>
		</tr>
		<tr >
			<td >Superplasticizer</td>
			<td >Subote New Materials Co., Ltd.</td>
			<td >PCA-III</td>
			<td>Polycarboxylated type, water reducing ratio is 35%</td>
		</tr>
		<tr >
			<td >Steel fiber</td>
			<td >Tianjin Hengfeng Xuxiang New Metal Materials Co., Ltd.</td>
			<td >Round straight</td>
			<td>Diameter 0.5mm, length 25mm</td>
		</tr>
	</tbody>
</table>

preparation of aligned steel fiber reinforced cementitious composite and its flexural behavior

この作業の目的は、コンパスの針が一直線に並べられた鋼繊維補強セメント系複合材料の製造のため、地球の磁場の作用の下で一貫した方向を維持して方法で触発され、アプローチを提示することです。一直線に並べられた鋼繊維補強セメント系複合材料 (ASFRC) は、均一な電磁界を短い鋼繊維が磁場に沿った回転に追い込まれたという短いの鋼繊維を含むモルタルに適用することにより調製しました。硬化 ASFRC における鋼繊維の配向の程度は、破断面における鋼繊維を数えると x 線トモグラフィー解析によって評価しました。2 つの方法からの結果を示す鋼における鋼繊維非磁気治療複合材料 ASFRC の繊維が高配向がランダムに配られました。整列鋼繊維がはるかに高い補強効率、および複合材料、したがって、大幅に強化された曲げ強度と靱性を展示します。ASFRC は、それは大きい引張応力に耐えることができ、もっと効果的に割れに抵抗にしたがって SFRC より優れています。

ASFRCs と SFRCs の 3 点曲げ試験から決定の曲げ強さは、図 5のとおりです。ASFRCs の曲げ強さは、すべて繊維用量の SFRCs のそれらより高くなっています。ASFRCs の曲げ強さは 88%, 71%, 57% 0.8%、1.2% 2.0% ・繊維容積比で SFRCs のそれらより高いであった。これらの結果は、一直線に並べられた鋼繊維がランダム スチール繊維より効果的にセメント系マトリ?...

Watch this Scientific Journal Video about Preparation of Aligned Steel Fiber Reinforced Cementitious Composite and Its Flexural Behavior at JoVE.com

Preparation of Aligned Steel Fiber Reinforced Cementitious Composite and Its Flexural Behavior

このプロトコルでは、均一な電磁界を適用することによって一直線に並べられた鋼繊維補強セメント系複合材料を製造するためのアプローチについて説明します。一直線に並べられた鋼繊維補強セメント系複合材料は、普通繊維補強コンクリートの優れた機械的特性を表わします。

一直線に並べられた鋼繊維の準備強化セメント系複合材料とその曲げ挙動

The aim of this work is to present an approach, inspired by the way in which a compass needle maintains a consistent orientation under the action of the ...

preparation-aligned-steel-fiber-reinforced-cementitious-composite-its

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Masonry Materials

SCIENTISTS IN ACTION

11.0K ビュー.  Hebei University of Technology. このプロトコルでは、均一な電磁界を適用することによって一直線に並べられた鋼繊維補強セメント系複合材料を製造するためのアプローチについて説明します。一直線に並べられた鋼繊維補強セメント系複合材料は、普通繊維補強コンクリートの優れた機械的特性を表わします。

ビデオ: Preparation of Aligned Steel Fiber Reinforced Cementitious Composite and Its Flexural Behavior

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

In recent years &pi;-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication.	
A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently &pi;-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important &pi;-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors and spintronics.	
Recently we have been able to address the above-mentioned issue by employing a novel "centrifugation-assisted" approach. This method therefore broadens the spectrum of organic materials that can be patterned in a vertically ordered nanowire array. Due to the technological importance of Alq3, rubrene and methanofullerenes, our method can be used to explore how the nanostructuring of these materials affects the performance of aforementioned organic devices. The purpose of this article is to describe the technical details of the above-mentioned protocol, demonstrate how this process can be extended to grow small-molecular organic nanowires on arbitrary substrates and finally, to discuss the critical steps, limitations, possible modifications, trouble-shooting and future applications.

We report a simple method for fabricating an ultrahigh density array of vertically ordered small-molecular organic nanowires. This method allows for synthesis of complex heterostructured hybrid nanowire geometries, which can be inexpensively grown on arbitrary substrates. These structures have potential applications in organic electronics, optoelectronics, chemical sensing, photovoltaics and spintronics.

任意の基板上の垂直配向小分子有機ナノワイヤーの超高密度アレイ

In  recent years &pi;-conjugated  organic semiconductors have emerged as the active material in a number of  diverse applications including large-area, ...

工学

Mechanical Expansion of Steel Tubing as a Solution to Leaky Wellbores

Wellbore cement, a procedural component of wellbore completion operations, primarily provides zonal isolation and mechanical support of the metal pipe (casing), and protects metal components from corrosive fluids. These are essential for uncompromised wellbore integrity. Cements can undergo multiple forms of failure, such as debonding at the cement/rock and cement/metal interfaces, fracturing, and defects within the cement matrix. Failures and defects within the cement will ultimately lead to fluid migration, resulting in inter-zonal fluid migration and premature well abandonment. Currently, there are over 1.8 million operating wells worldwide and over one third of these wells have leak related problems defined as Sustained Casing Pressure (SCP)1. 
The focus of this research was to develop an experimental setup at bench-scale to explore the effect of mechanical manipulation of wellbore casing-cement composite samples as a potential technology for the remediation of gas leaks. 
The experimental methodology utilized in this study enabled formation of an impermeable seal at the pipe/cement interface in a simulated wellbore system. Successful nitrogen gas flow-through measurements demonstrated that an existing microannulus was sealed at laboratory experimental conditions and fluid flow prevented by mechanical manipulation of the metal/cement composite sample. Furthermore, this methodology can be applied not only for the remediation of leaky wellbores, but also in plugging and abandonment procedures as well as wellbore completions technology, and potentially preventing negative impacts of wellbores on subsurface and surface environments.

This article reports on a laboratory scale investigation of an existing field procedure and its adaptation for sealing of leaky wellbores. It consists of mechanical expansion of metal pipe, which results in an improved metal/cement bond, ultimate sealing of hydraulic pathways and prevention of gas leaks caused by the presence of a microannular channel.

漏洩坑の解決策として鋼チューブの機械的な拡張

Wellbore cement, a procedural component of wellbore completion operations, primarily provides zonal isolation and mechanical support of the metal pipe ...

A Testing Platform for Durability Studies of Polymers and Fiber-reinforced Polymer Composites under Concurrent Hygrothermo-mechanical Stimuli

The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs and condition-based maintenance. These materials are adopted in a wide range of engineering applications, from aircraft and ship structures, to bridges, wind turbine blades, biomaterials and biomedical implants. Polymers are viscoelastic materials, and their response may be highly nonlinear and thus make it challenging to predict and monitor their in-service performance. The laboratory-scale testing platform presented herein assists the investigation of the influence of concurrent mechanical loadings and environmental conditions on these materials. The platform was designed to be low-cost and user-friendly. Its chemically resistant materials make the platform adaptable to studies of chemical degradation due to in-service exposure to fluids. An example of experiment was conducted at RT on closed-cell polyurethane foam samples loaded with a weight corresponding to ~50% of their ultimate static and dry load. Results show that the testing apparatus is appropriate for these studies. Results also highlight the larger vulnerability of the polymer under concurrent loading, based on the higher mid-point displacements and lower residual failure loads. Recommendations are made for additional improvements to the testing apparatus.

The durability of polymers and fiber-reinforced polymer composites in service is a critical aspect for their designs and condition-based maintenance. We present a novel low-cost laboratory testing platform for the investigation of the influence of concurrent mechanical and environmental loadings, and may help design more efficient yet safer composite structures.

同時Hygrothermo-機械的刺激下でのポリマーおよび繊維強化ポリマー複合材料の耐久性研究のための試験プラットホーム

The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs ...

Strain Sensing Based on Multiscale Composite Materials Reinforced with Graphene Nanoplatelets

The electrical response of NH2-functionalized graphene nanoplatelets composite materials under strain was studied. Two different manufacturing methods are proposed to create the electrical network in this work: (a) the incorporation of the nanoplatelets into the epoxy matrix and (b) the coating of the glass fabric with a sizing filled with the same nanoplatelets. Both types of multiscale composite materials, with an in-plane electrical conductivity of ~10-3 S/m, showed an exponential growth of the electrical resistance as the strain increases due to distancing between adjacent functionalized graphene nanoplatelets and contact loss between overlying ones. The sensitivity of the materials analyzed during this research, using the described procedures, has been shown to be higher than commercially available strain gauges. The proposed procedures for self-sensing of the structural composite material would facilitate the structural health monitoring of components in difficult to access emplacements such as offshore wind power farms. Although the sensitivity of the multiscale composite materials was considerably higher than the sensitivity of metallic foils used as strain gauges, the value reached with NH2 functionalized graphene nanoplatelets coated fabrics was nearly an order of magnitude superior. This result elucidated their potential to be used as smart fabrics to monitor human movements such as bending of fingers or knees. By using the proposed method, the smart fabric could immediately detect the bending and recover instantly. This fact permits precise monitoring of the time of bending as well as the degree of bending.

The integration of conductive nanoparticles, such as graphene nanoplatelets, into glass fiber composite materials creates an intrinsic electrical network susceptible to strain. Here, different methods to obtain strain sensors based on the addition of graphene nanoplatelets into the epoxy matrix or as a coating on glass fabrics are proposed.

グラフェンナノプレートレットとマルチスケール複合材料強化に基づくひずみセンシング

The electrical response of NH2-functionalized graphene nanoplatelets composite materials under strain was studied. Two different manufacturing methods are ...

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.

新しい複合加工法の試作: 軟層法による複合表面にファイバーを公開

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 ...

Preparation and High-temperature Anti-adhesion Behavior of a Slippery Surface on Stainless Steel

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A typical anti-wetting superhydrophobic surface easily fails when exposed to a high-temperature liquid. Recently, Nepenthes-inspired slippery surfaces demonstrated a new way to solve the adhesion problem. A lubricant layer on the slippery surface can act as a barrier between the repelled materials and the surface structure. However, the slippery surfaces in previous studies rarely showed high-temperature resistance. Here, we describe a protocol for the preparation of slippery surfaces with high-temperature resistance. A photolithography-assisted method was used to fabricate pillar structures on stainless steel. By functionalizing the surface with saline, a slippery surface was prepared by adding silicone oil. The prepared slippery surface maintained the anti-wetting property for water, even when the surface was heated to 300 &#176;C. Also, the slippery surface exhibited great anti-adhesion effects on soft tissues at high temperatures. This type of slippery surface on stainless steel has applications in medical devices, mechanical equipment, etc.

Slippery surfaces provide a new way to solve the adhesion problem. This protocol describes how to fabricate slippery surfaces at high temperatures. The results demonstrate that the slippery surfaces showed anti-wetting for liquids and a remarkable anti-adhesion effect on soft tissues at high temperatures.

ステンレス鋼の滑りやすい表面の作製と高温の反付着挙動

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A ...

Installation Method to Enhance Quality Control for Fiber Reinforced Polymer Spike Anchors

Fiber reinforced polymer (FRP) anchors are a promising way to enhance the performance of externally-bonded FRPs applied to existing structures, as they can delay or even prevent debonding failure. However, a major concern faced by designers is the premature failure of the anchors due to stress concentration. Poor installation quality and preparation of the clearance holes can result in stress concentration that provokes this premature failure. This paper deals with an installation method that aims to reduce the impact of the stress concentration and to provide a proper quality control of the preparation of the drill hole. The method involves three parts: the drilling and cleaning of the holes, the smoothing of the hole edges with a customized drill bit, and the installation of the anchor itself, including the impregnation of the anchor dowel and its insertion. Anchor fans (the free length of the spikes) are then bonded to the external FRP reinforcement. For the end anchorage, and in the case of reinforcements with multiple plies, it is recommended that the anchor fan be inserted between two plies to assist the stress-transfer mechanism. 
The proposed procedure is complemented with a design approach for spike anchors, based on an extensive database. It is proposed that the design follow a number of steps, namely: selection of the anchor diameter and subsequent tensile strength of the connector (that is to say, the anchor before fanning out the free end), evaluation of the reduction in the tensile strength due to bending, provision of enough embedment to prevent slippage failure, and consideration of the number and spacing of anchors for a given reinforcement. In this sense, it should be noted that further research is needed in order to obtain a general expression for the contribution of spike anchors to overall bond strength of FRP reinforcements.

This manuscript presents a method for controlling the quality of installation for spike anchors designed to delay delamination of externally bonded fiber reinforced polymers. The protocol includes the preparation of the drill hole and the insertion process. The most influential parameters on the efficiency of the anchors are discussed.

繊維の品質管理を強化するインストール方法強化ポリマー スパイク アンカー

Fiber reinforced polymer (FRP) anchors are a promising way to enhance the performance of externally-bonded FRPs applied to existing structures, as they ...

Applicability Analysis of Assessment Methods for Morphological Parameters of Corroded Steel Bars

The irregular and uneven residual sections along the length of a corroded steel bar substantially change its mechanical properties and significantly dominate the safety and performance of an existing concrete structure. As a result, it is important to measure the geometry and amount of corrosion of a steel bar in a structure properly to assess the residual bearing capacity and service life of the structure. This paper introduces and compares five different methods for measuring the geometry and amount of corrosion of a steel bar. A single 500 mm long and 14 mm diameter steel bar is the specimen that is subjected to accelerated corrosion in this protocol. Its morphology and the amount of corrosion were carefully measured before and after using mass loss measurements, a Vernier caliper, drainage measurements, 3D scanning, and X-ray micro-computed tomography (XCT). The applicability and suitability of these different methods were then evaluated. The results show that the Vernier caliper is the best choice for measuring the morphology of a non-corroded bar, while 3D scanning is the most suitable for quantifying the morphology of a corroded bar.

This paper measures the geometry and the amount of corrosion of a steel bar using different methods: mass loss, calipers, drainage measurements, 3D scanning, and X-ray micro-computed tomography (XCT).

鉄筋腐食分布の形態学的パラメーターの評価法の適用性について分析

The irregular and uneven residual sections along the length of a corroded steel bar substantially change its mechanical properties and significantly ...

Design and Fabrication of an Optical Fiber Made of Water

In this report, an optical fiber of which the core is made solely of water, while the cladding is air, is designed and manufactured. In contrast with solid-cladding devices, capillary oscillations are not restricted, allowing the fiber walls to move and vibrate. The fiber is constructed by a high direct current (DC) voltage of several thousand volts (kV) between two water reservoirs that creates a floating water thread, known as a water bridge. Through the choice of micropipettes, it is possible to control the maximal diameter and length of the fiber. Optical fiber couplers, at both sides of the bridge, activate it as an optical waveguide, allowing researchers to monitor the water fiber capillary body waves through transmission modulation and, therefore, deducing changes in surface tension.
Co-confining two important wave types, capillary and electromagnetic, opens a new path of research in the interactions between light and liquid-wall devices. Water-walled microdevices are a million times softer than their solid counterparts, accordingly improving the response to minute forces.

This protocol describes the design and manufacture of a water bridge and its activation as a water fiber. The experiment demonstrates that capillary resonances of the water fiber modulate its optical transmission.

水の光ファイバーの設計と製作

In this report, an optical fiber of which the core is made solely of water, while the cladding is air, is designed and manufactured. In contrast with ...

Expression of Cementitious Pore Solution and the Analysis of Its Chemical Composition and Resistivity Using X-ray Fluorescence

The goal of this method is to determine the chemical composition and electrical resistivity of cementitious pore solution expressed from a fresh paste sample. The pore solution is expressed from a fresh paste sample using a pressurized nitrogen gas system. The pore solution is then immediately transferred to a syringe to minimize evaporation and carbonation. After that, assembled testing containers are used for the X-ray fluorescence (XRF) measurement. These containers consist of two concentric plastic cylinders and a polypropylene film which seals one of the two open sides. The pore solution is added into the container immediately prior to the XRF measurement. The XRF is calibrated to detect the main ionic species in the pore solution, in particular, sodium (Na+), potassium (K+), calcium (Ca2+), and sulfide (S2-), to calculate sulfate (SO42-) using stoichiometry. The hydroxides (OH-) can be calculated from a charge balance. To calculate the electrical resistivity of the solution, the concentrations of the main ionic species and a model by Snyder et al. are used. The electrical resistivity of the pore solution can be used, along with the electrical resistivity of concrete, to determine the formation factor of concrete. XRF is a potential alternative to current methods to determine the composition of pore solution, which can provide benefits in terms of reduction in time and costs.

This protocol describes the procedure to express fresh pore solution from cementitious systems and the measurement of its ionic composition using X-ray fluorescence. The ionic composition can be used to calculate pore solution electrical resistivity, which can be used, together with concrete electrical resistivity, to determine the formation factor.

セメント細孔溶液の化学組成の蛍光 x 線を用いた比抵抗解析式

The goal of this method is to determine the chemical composition and electrical resistivity of cementitious pore solution expressed from a fresh paste ...