粘着接触下硬质涂层/韧性基底系统界面分层的有限元分析

Finite element analysis of interfacial delamination for brittle coatings / ductile substrates subjected to adhesive contact loads

建立了球形压头与弹性涂层/弹塑性基底系统间粘着接触的有限元模型,采用满足Lennard-Jones力定律的非线性轴向连接器来模拟压头与涂层间的表面粘附作用,并由内聚力模型来模拟涂层/基底的界面分层。研究了不同粘着功下,表面间的粘附作用对界面分层的影响。结果表明,增大粘着功会促使界面分层的产生。对于产生分层的曲线,卸载响应由五个连续阶段组成:弹性恢复、界面损伤起始(开裂)、界面损伤扩展(分层)、涂层弹性弯曲以及表面突然分离(jump-out)。

The finite element simulation of a rigid sphere in adhesive contact with an elastic coating on an elastic - plastic substrate is undertaken to clarify interface crack initiation and grown, in which the surface adhe- sion of indenter/coating contact system is modeled by nonlinear spring elements with a force - displace- ment relationship derived from the Lennard- Jones potential, and the coating/substrate interface is re- presented by an irreversible cohesive zone law. For different adhesion works, the effect of the surface adhesion on interface delamination is investigated. It is found that increasing the adhesion work will prompt delamination nucleation. Moreover, the unloading response consists of five sequential stages： e- lastic recovery, interface damage （crack） initiation, damage evolution （delamination）, coating elastic bending, and abrupt surface detachment （jump - out）.