北京生物医学工程

压入实验考虑曲率时弹性模量的确定方法

Determination method for the elastic modulus of indented solid with curved surface in indentation test

作者：钱秀清张昆亚张海霞刘志成

单位：首都医科大学生物医学工程学院（北京100069）

分类号：

出版年·卷·期（页码）：2012·31·5（441-444）

摘要：

目的针对平压头压入曲面材料的问题，提出了考虑曲面曲率时弹性模量的确定方法。方法首先利用有限元方法研究曲率对压入响应的影响，然后利用量纲分析与有限元方法，给出压入载荷的无量纲表达式，并提出考虑被压材料为曲面时弹性模量的确定方法，最后用数值算例验证方法的有效性。结果数值算例结果显示，本方法研究曲面材料的识别弹性模量的相对误差均小于4%，且精度较高。结论对于角膜、巩膜等生物软组织材料，用压入法确定材料力学特性时，材料表面曲率的影响不可忽略。

Objective For the problem of the indented solid with curved surface using flat punch indentation, a method is proposed to identify the elastic modulus of materials. Methods Firstly, the effect of curvature on the indentation response is studied with the finite element method. Then, according to the dimensional analysis and finite element method, a dimensionless function expression of indention force can be obtained and the elastic modulus can be determined. Finally, the performance of the method is verified by the numerical experiments. Results The results of the numerical examples show that the maximum relative error of the identified elastic modulus of the indented solid with curved surface is 4%, which shows that the identified results are acceptable. Conclusions While the mechanical properties are determined by the indentation test, the effect of the curvature should not be ignored for certain soft tissues, such as cornea and sclera.

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