基于应力三轴度和罗德参数的6061和7075铝合金材料断裂失效分析

分别对6061铝合金和7075铝合金材料的缺口圆棒试件和凹槽平板试件进行准静态拉伸试验,并采用ABAQUS软件对拉伸过程进行数值模拟。模拟结果与试验测试结果吻合很好,验证了有限元模型的合理性和可靠性。通过有限元模拟,分别给出了不同试件的应力三轴度和罗德参数随等效塑性应变的变化曲线以及两种材料的失效轨迹,并对它们进行了分析讨论。结果表明:形状相同、材料性质不同的试件,应力三轴度的演化规律不同;材料的失效应变受应力三轴度和罗德参数的影响,并且不同性质的材料对罗德参数的敏感性不同。

Fracture Failure Analysis of 6061 and 7075 Aluminum Alloy Based on Stress Triaxiality and Lode Parameter

Quasi-static tensile experiments were conducted for notched round bar specimens and grooved flat plate specimens made of 6061 aluminum alloy and 7075 aluminum alloy,respectively.In addition,ABAQUS software was adopted to numerically simulate the tensile processes.Good agreement between tensile experimental results and numerical simulation results verifies the rationality and reliability of the finite element model.By means of finite element simulation,the variation curves of stress triaxiality and Lode parameter with the equivalent plastic strain were obtained respectively for different representative specimens.Similarly,the failure loci of two kinds of alloy materials were drawed and discussed.The results show that specimens,which have the same shape but different materials,exhibit different stress triaxiality evolution patterns;the failure strain of material is affected by both stress triaxiality and Lode parameter;the sensitivity to Lode parameter is different for different materials.