复合材料L型接头的承载性能和损伤机理研究

Research on load-carrying properties and damage mechanism of composite L-joint

通过试验和数值计算分析了三明治复合材料L型接头的弯曲承载性能和损伤机理.首先,进行了三种尺寸接头试件的压弯试验,分析了过渡区倒角半径和蒙皮厚度对接头承载能力的影响,并对其损伤特征进行了分析;然后,开展芯材压缩试验,获取芯材塑性参数,并建立了芯材压缩的数值仿真模型;最后,建立了L型接头在试验条件下的准静态仿真模型,将仿真结果和试验结果进行比较,分析了接头的损伤机理及承载能力随过渡区倒角半径和蒙皮厚度的变化规律.结果显示:压弯载荷作用下,三明治复合材料L型接头的损伤是由过渡区芯材的塑性变形导致,通过增大过渡区倒角半径和蒙皮厚度,可以显著提高接头的承载性能;仿真结果和试验结果符合较好,验证了数值计算模型的合理性.

The bending load-carrying properties and damage mechanism of sandwich composite L-join was researched by experiment and numerical calculation.Firstly,the bending experiment of L-joint specimens with three different dimensions was carried out,and then the effect of the radius and skin thickness of the transition region to the load-carrying properties as well as the damage characteristics was analyzed.Secondly,the core's compressed experiment was carried out in order to obtain the plastic parameters of the core,and then numerical simulation model of the core compress was presented.Finally,the quasi-static simulation model of L-joint under the test conditions was presented,the simulated results were compared to the test results,and then the damage mechanism and the variation of the radius and skin thickness of the transition region to the load-carrying properties were analyzed.It can be seen that sandwich composite L-joint damage is mainly manifested as the core plastic deformation,and enlarging the radius and skin thickness of the transition region can increase the load-carrying capacity,and then the simulated results agreeing well to the test results verifies the rationality of the numerical model.