基于连续损伤力学的铝车身涂层抗划伤能力

Scratch resistance of aluminum automotive coatings based on continuum damage mechanics

开展了基于连续损伤力学(CDM)的涂层抗划伤能力仿真研究,建立了损伤力学材料模型。通过有限元软件ABAQUS提供的子程序(VUMAT)接口,将该材料模型嵌入到ABAQUS求解器。以裂纹横穿涂层的压头反力来衡量涂层的抗划伤能力,预测涂层抗划伤能力。研究发现:用所建立的自定义材料模型对涂层划伤进行分析,不仅可以得到涂层的应力分布,而且可以预测涂层在载荷作用下裂纹的产生和扩展趋势;涂层对划伤速度高的载荷具有更高的抵抗划伤能力,涂层厚度对涂层抗划伤能力也有一定影响;而基体材料性能和基体厚度对涂层抗划伤能力的影响很小,研究结论可以为涂层材料的优化设计提供理论支持。

Continuum Damage Mechanics(CDM)was introduced into the finite element analysis of scratch resistance of coatings.Firstly,a damage mechanics based on the material model was created.Secondly,this material model was implemented into ABAQUS solver through user defined subroutine VUMAT.Finally,a series of analyses were carried out to analyze the mechanical behavior of coatings.The material model could be used not only to capture the stress distribution of coatings,but also to predict the damage evolution of coatings under scratch loading.In addition,it is found that the loading speed and coating thickness have certain effects on scratch resistance,but the properties and thickness of substrate have little effect on it.The theoretical support was provided for the optimal design of the coating material.