NUMERICAL STUDY ON PROPERTIES OF WEAK INTERLAYER OF LAMINATED COMPOSITE

<正>With assumption of material inhomogeneity on meso level,a three-point bending beam model has been adopted to simulate crack propagation in two dimensional laminated composite and to verify the toughening mechanism of energy dissipation and crack deflection along the weak interlayer.Moreover,the effect of strength,elastic modulus and thickness of the weak interlayer on both strength and toughness of the laminated composite have also been investigated in this paper.     

酚醛树脂层压基板真空热裂解产物分析表征

利用程序升温的热解炉反应器对酚醛树脂层压基板进行真空热裂解,通过元素分析、傅里叶红外(FT-IR)分析和气相色谱-质谱(GC-MS)分析,对原料及产物油成分进行了表征。研究表明,热解油上层清液主要是一些较易溶于水的物质,如苯酚、甲酚、二甲酚、糖类、乙内酰脲类、吗啉类、吡喃酮类和吡啶类化合物等;而下层沉淀则主要为不溶或难溶于水的物质,如大取代基酚类(取代基碳原子数≥2)、磷酸三芳基酯类、脂肪酸酯类和腈类化合物等。其中,三聚氰胺在上层清液和下层沉淀中都有较高的含量。     

Laminated Polymer Solar Cells with PEDOT：PSS Film as Anode

A prefabricated conductive polymer film of polymer poly（3,4-ethylenedioxy-thiophene）：poly （styrene-sulfonate） （PEDOT：PSS） is developed and is used as the anode in an inverted polymer solar cell （PSC） through a lamination process. The geometry structure of the PSC is indium tin oxide/interface layer/P3HT：PCBM/PEDOT：PSS. The PEDOT：PSS electrode is 5 μm and the sheet resistance is 10Ω/sq. The device fabrication process is vacuum-free and extremely simple. Lithium carbonate （Li2CO3） and cesium carbonate （Cs2C03） are used as the cathode interface layers, respectively, and the result shows that Li2CO3 can enhance the open-circuit voltage （Voc） and fill factor distinctly, and the power conversion efficiency （PCE） can reach 2.1%.     

Tunable characteristics of bending resonance frequency in magnetoelectric laminated composites

As the magnetoelectric (ME) effect in piezoelectric/magnetostrictive laminated composites is mediated by mechanical deformation, the ME effect is significantly enhanced in the vicinity of resonance frequency. The bending resonance frequency (fr) of bilayered Terfenol-D/PZT (MP) laminated composites is studied, and our analysis predicts that (i) the bending resonance frequency of an MP laminated composite can be tuned by an applied dc magnetic bias (Hdc) due to the E effect; (ii) the bending resonance frequency of the MP laminated composite can be controlled by incorporating FeCuNbSiB layers with different thicknesses. The experimental results show that with H dc increasing from 0 Oe (1 Oe=79.5775 A/m) to 700 Oe, the bending resonance frequency can be shifted in a range of 32.68 kHz≤fr≤33.96 kHz. In addition, with the thickness of the FeCuNbSiB layer increasing from 0 μm to 90 μm, the bending resonance frequency of the MP laminated composite gradually increases from 33.66 kHz to 39.18 kHz. This study offers a method of adjusting the strength of dc magnetic bias or the thicknesses of the FeCuNbSiB layer to tune the bending resonance frequency for ME composite, which plays a guiding role in the ME composite design for real applications.     

Two-dimensional analyses of delamination buckling of symmetrically cross-ply rectangular laminates

The conventional approach to analysis the buckling of rectangular laminates containing an embedded delamination subjected to the in-plane loading is to simplify the laminate as a beam-plate from which the predicted buckling load decreases as the length of the laminate increases. Two-dimensional analyses are employed in this paper by extending the one-dimensional model to take into consideration of the influence of the delamination width on the buckling performance of the laminates. The laminate is simply supported containing a through width delamination. A new parameter β defined as the ratio of delamination length to delamination width is introduced with an emphasis on the influence of the delamination size. It is found that (i) when the ratio β is greater than one snap-through buckling prevails, the buckling load is determined by the delamination size and depth only; (ii) as the ratio β continues to increase, the buckling load will approach to a constant value. Solutions are verified with the well established results and are found in good agreement with the latter.     

固化条件对太阳电池EVA胶膜交联度的影响

介绍了EVA胶膜对太阳电池组件的影响以及EVA胶膜交联度的测试方法.通过测试交联度来优化设定太阳电池组件层压的层压时间、温度等影响因素,使得太阳电池组件转化效率最大化,并保证可靠的使用寿命.通过对不同位置的EVA胶膜交联度测试,来检测层压机表面各个区域温控的工作情况,以保证太阳电池组件批量生产的合格率.     

层压工艺对埋入光纤传输性能影响分析

针对层压工艺下,埋入挠性光电基板的光纤,其应力、位移的变化,会影响光路的耦合效率,改变光纤有效折射率,导致传输性能发生变化的问题,采用有限元分析软件,对光纤埋入不同槽型的挠性光电基板进行了力学、传热和电磁场耦合分析.分析结果表明:光纤埋入梯形槽挠性基板的应力最大,达到68.336 7MPa.埋入梯形槽的光纤位移量最大,其值为1.430 4μm.随着槽宽增加,光纤最大等效应力从52.667MPa增加至71.907 MPa;随着槽间距增加,光纤最大应力从51.589 MPa增加至53.567MPa;随着槽深增加,光纤最大应力从52.667MPa减小至47.793 8 MPa,然后增加到67.349 6MPa.随着温度和压力的增加,单模光纤在X方向的有效折射率从1.446 249 977增加至1.446 259 084;Y方向的有效折射率从1.446 326 398增加至1.446 393 041.光纤有效折射率差会随着温度的增加而增大,随着压力的增加而减小.光纤有效折射率增加,限制光的能力增加,能够有效地减小光纤弯曲损耗.本文分析结果对挠性光电基板光纤埋入结构设计和层压工艺具有一定的参考价值和指导意义.     

非均相接枝共聚制备极性聚丙烯

在甲苯－水介质中制备了聚丙烯－ｇ－甲基丙烯酸（ＰＰ－ｇ－ＭＡＡ）．用正交实验设计研究了引发剂、单体用量及反应时间等因素对反应的影响．用裂解色谱、扫描电镜对接枝物进行表征．接枝聚丙烯对极性材料如尼龙、铝箔、碳酸钙的界面亲合力有大幅度提高     

Force-displacement characteristics of simply supported beam laminated with shape memory alloys

As a preliminary step in the nonlinear design of shape memory alloy(SMA) composite structures,the force-displacement characteristics of the SMA layer are studied.The bilinear hysteretic model is adopted to describe the constitutive relationship of SMA material.Under the assumption that there is no point of SMA layer finishing martensitic phase transformation during the loading and unloading process,the generalized restoring force generated by SMA layer is deduced for the case that the simply supported beam vibrates in its first mode.The generalized force is expressed as piecewise-nonlinear hysteretic function of the beam transverse displacement.Furthermore the energy dissipated by SMA layer during one period is obtained by integration,then its dependencies are discussed on the vibration amplitude and the SMA’s strain(Ms-Strain) value at the beginning of martensitic phase transformation.It is shown that SMA’s energy dissipating capacity is proportional to the stiffness difference of bilinear model and nonlinearly dependent on Ms-Strain.The increasing rate of the dissipating capacity gradually reduces with the amplitude increasing.The condition corresponding to the maximum dissipating capacity is deduced for given value of the vibration amplitude.The obtained results are helpful for designing beams laminated with shape memory alloys.