复合材料的冲击吸能与动态黏弹特性

考察了玻璃纤维、炭纤维、芳纶和UHMWPE纤维复合材料(分别称为GFRP,CFRP,AFRP和DFRP)层板的低速冲击吸能,并采用高载动态热机械分析仪EPLEXOR500分析了其纤维复丝的动态黏弹性的载荷敏感性.结果表明:冲击吸能明显受纤维性能及层板破坏模式的影响,呈韧性破坏的AFRP和DFRP的冲击吸能明显高于呈脆性破坏的GFRP和CFRP.在动态热机械分析中,静载增大使得储能模量升高但损耗角正切减小,动载增大时正好相反,且在这些影响中有机纤维复丝动态黏弹性较无机纤维复丝表现出更显著的载荷敏感性和非线性.4种层板的吸能大小与其纤维复丝储能模量载荷敏感性的强弱以及损耗角正切大小的顺序相同:DFRP>AFRP>GFRP>CFRP,反映出材料宏观冲击性能与表征其微观结构特征的黏弹性能的相关性.

Impact energy absorption and dynamic viscoelasticity of composites

The energy absorptions of composite laminates reinforced respectively by glass fiber,carbon fiber,aramid fiber,and UHMWPE fiber(separately named as GFRP,CFRP,AFRP and DFRP),were investigated under the low velocity impact.The load sensibilities on dynamic viscoelasticity of composite fiber bundles of these four kinds of fibers were analyzed by using the EPLEXOR500 dynamic mechanical thermal analyzer under high loads.The impact tests show that the impact energy absorption is close related to the fiber properties and failure modes.The impact energy absorptions of AFRP and DFRP laminates through ductile failures are much higher than those of GFRP,and CFRP laminates through brittle failures.Dynamic mechanical thermal analysis of composite fiber bundles show the load effects as that storage modulus increase and loss tangents decrease with the increasing static load,while the case is just reverse with the increasing dynamic load.In these effects,the organic fibers exhibit more serious load sensibilities and non-linearity than the inorganic fibers.These four laminates show the same sequence DFRP>AFRP>GFRP>CFRP on energy absorption as the load sensibility of storage modulus or the value of loss tangent of composite fiber bundles.This reflectes the correlation of the macroscopic impact performance and viscoelasticity which is close associated with material microstructure.