压入法中的接触问题

针对表面工程中测量膜基材料性能或结合强度的压入法,分析了其实验过程中所涉及的重要而又困难的接触问题。在引入适当的假设后,文中首次对二维、三维问题等一般情况,分别给出了控制接触的边界条件方程,并进一步使用半解析的数值方法——线法,针对二维情况使用,球形压头和楔形压头分别进行了数值模拟,并将计算结果和不考虑接触情况下的结果进行了比较结果表明:剪应力差别巨大,这说明接触问题的考虑对于正确地处理实际问题是非常必要的。

Contact Problems in Indentation Test

In this paper, important and difficult contact problems are tackled for the indentation test to measure the material properties of the matrix and/or the substrate or the adhesion strength in surface engineering. First, the boundary condition equations controlling the contact are given for two dimension strength and three dimensional problems based on some approriate assumptions. Then, the semi-analytic numeral methos, i. e. Method of Lines (MOL) is adopted to simulate the indentation of the sphere-shape indenter and the wedge-shape indenter respectively for the two dimensional problems. At last, the same cases are also computed with no contact problems considered. The comparison of their corresponding results shows that the difference of the shearing stresses is very large. Therefore, it is necessary very much to consider the contact problems in order to deal with the test correctly.