单向EMC层合板折叠变形时面内/面外屈曲形式的判据

JUDGEMENT OF IN-PLANE/OUT-OF-PLANE MICROBUCKLING MODE FOR PACKAGED UNIDIRECTIONAL EMC LAMINATES

形状记忆聚合物复合材料(Elastic Memory Composite,EMC)是一种新型功能材料,具有高极限应变、高比刚度和低密度等优点,在未来空间展开技术中极具应用潜力。在热激活温度下,EMC层合板基体呈现高弹态,其剪切模量极低,不能提供对纤维的有效约束。在该状态下,层合板承受弯曲载荷作用时,压缩区的纤维能够通过微屈曲实现较大折叠变形。该文依据极小势能原理分别计算其发生面内和面外屈曲各自所产生的总势能极小值,而实际发生的纤维屈曲形式应是极小总势能值相对较小的那一种,从而确定其最终屈曲模式。经实例验证,理论结果与实验结果相符。

Elastic memory composite（EMC） materials are a new class of functional materials and have great potential applications in future space deployable structures due to their advantages of high failure strain,high specific modulus,and low density.At elevated temperature,the matrix of EMC laminates is in a rubbery state and its very low shear modulus cannot provide an effective constraint for the fibers.Hence,EMC laminates can realize a large packaging strain through the microbuckling of compressed fibres under bending.In this study,according to the principle of minimum potential energy,the total potential energies of EMC laminates are respectively calculated under in-plane and out-of-plane microbuckling modes.Considering that the real microbuckling mode should be the one that produces lower total potential energy,the theoretical microbuckling mode of unidirectional EMC laminates is determined under bending and is agreeable with the testing results.