航空用芳纶纸蜂窝各向异性行为研究

采用Arcan加载装置对航空用芳纶纸蜂窝试件进行一系列面外压剪复合加载实验,以此研究材料各向异性行为。实验结果表明:随着面内方向角增加,芳纶纸蜂窝面内等效剪切模量、等效剪切强度显著减小,实验屈服面显著扩张,材料表现出明显的各向异性。基于实验结果,确定了测试蜂窝面内等效剪切模量、等效剪切强度上下限值及其比值关系,并与理论值进行比较。一个适用于各向异性材料的屈服准则与实验屈服面进行比较,比较结果表明:屈服准则能大致描述蜂窝各向异性屈服行为。

Anisotropic Behaviors of Nomex Hoenycombs

In order to investigate anisotropic behaviors, a series of combined compression and shear loading experiments out-plane for aerospace Nomex honeycomb specimens were conducted by using ARCAN loading device. Experimental results indicate that the in-plane orientation angle has significant influence on in-plane equivalent shear modulus, equivalent shear strength (both amount are significantly reduced), and initial yield surface (significantly expansed). This material presents obvious anisotropic. Based on experimental results, the upper and lower limits and ratio for equivalent shear strength and equivalent shear modulus were determined and compared with theoretical results. A phenomenological yield criterion for anisotropic materials was compared with experimental initial yield surface. Results show that experimental initial yield surface of tested specimens is approximately consistent with theoretical yield surface, which indicates that the phenomenological yield criteria can properly describe the development of experimental yield surface of tested honeycomb.