蠕变压痕实验的计算机模拟

THE SIMULATION OF CREEP INDENTATION TESTING

  • 摘要: 采用有限元的方法对双相材料的蠕变压痕实验进行了数值模拟,在有限元数值解的基础上,定义了相应于传统单轴蠕变实验的“等效应力”和“等效应变”,建立了蠕变压痕实验同传统单轴蠕变实验之间的关系,给出了确定薄膜蠕变应力指数和蠕变常数的方法;同时数值解的结果表明,实验中通过控制压痕深度不超过薄膜厚度的5%~10%,忽略基体的硬化指数对确定薄膜性能的影响存在一定的误差,但基体的弹性模量对确定薄膜的蠕变性能影响不大.

     

    Abstract: Finite Element Method (FEM) was used to simulate the creep indentationtesting on film/substrate systems. Based on the FEM simulation, a new methodis proposed to derive the material creep properties (in Norton equation) fromthe indention creep experimental results (indentation stress-indenterdepth-time) for thin film/substrate systems by the definition of`effective' stress and `effective'strain. In the simulation, a steady state was found and the steady state was used toconstruct the relationship between the traditional uniaxial tensile creep testing andindentation testing. In the simulation of the creep indentationtesting, FEM-results showed that the experimental results would havesome error from ignoring the influence of the substrates even if theindentation depth did not exceed 5%~10% depth of film.

     

/

返回文章
返回