纳米TiB_(2)/7075铝基复合材料超声滚压数值仿真研究

Research on Numerical Simulation of Ultrasonic Rolling of Nano TiB_(2)/7075 Aluminum Matrix Composites

超声滚压数值仿真研究亟待丰富和深入开展。采用温度-应变率相关Johnson-Cook本构模型描述纳米TiB_(2)/7075铝基复合材料塑性变形行为,通过Gleeble热压缩模拟实验结合最小二乘拟合标定相关本构参数。利用有限元软件ABAQUS构建3D全六面体渐变网格模型,通过6个步骤对复合材料超声滚压强化过程进行了数值仿真研究。结果表明,残余应力分布的仿真结果与实测结果存在明显差异,但网格失效形式较好地反映了表层材料的开裂和分层,从模拟角度验证了往复超声滚压过程中过度塑性变形导致材料表面损伤的现象。该结果对金属基复合材料超声滚压工艺的探索和相关数值仿真研究的深入开展具有重要指导意义。

Numerical simulation of ultrasonic rolling pressure needs to be enriched and further developed.The temperature-strain rate dependent Johnson-Cook constitutive model was used to describe the plastic deformation behavior of nano-sized TiB_(2)/7075 aluminum matrix composites,and the relevant constitutive parameters were calibrated by Gleeble thermal compression simulation test combined with least square fitting.Using finite element software ABAQUS,3D full hexahedron gradient mesh model was constructed.The ultrasonic rolling strengthening process of composite materials was numerically simulated by six steps.The results show that there is a significant difference between the simulation results and the measured results in terms of residual stress distribution,but the failure mode of the mesh reflects the cracking and delamination of the surface material well.From the simulation point of view,it is confirmed that the excessive plastic deformation in the reciprocating ultrasonic rolling process causes the surface damage of the composite.The results have important guiding significance for the exploration of ultrasonic rolling of metal matrix composites and the development of related numerical simulation research.