压痕轮廓信息在材料本构关系反演测量中的应用

Application of Residual Imprint Profile to Material Constitutive Relation in Identification Via Inverse Analysis

金属材料的力学性能,如本构关系可以利用纳米压痕技术反演测量得到,但是测量结果存在不准确、不唯一的问题。为了解决该问题,本文中提出同时利用载荷-位移曲线和压痕轮廓信息来提高本构关系中材料参数的测量精度。利用ANSYS建立了纳米压痕数值模型,通过对比数值模拟和实验获得的载荷-位移曲线,验证了数值模拟的可行性和可靠性;反演测量需要优化迭代来缩小数值模拟与实验的差距,由于ANSYS在优化算法上存在不足,利用MATLAB强大的编程能力,编制了对应的优化求解算法,并且和ANSYS联合求解完成材料本构关系的反演测量。最后,通过实例证明引入压痕轮廓信息可以提高材料本构关系反演测量的准确性和唯一性。

The mechanical properties of metals, such as its constitutive relationship can be identified via indentation testing based on the inverse analysis method. However, the identified results are usually not accurate or even not uniqueness. In order to solve this problem, to utilize both loading-displacement curve and residual imprint profile to improve the accuracy of the identified material parameters is proposed. The numerical indentation model is built via ANSYS software, the simulated results are compared to the experimental data for verifying that the numerical indentation model is reliable and available. The identification process is in fact to minimize the difference between the simulated and experimental results via optimization iterations. However, due to the insufficiency of ANSYS in optimization algorithms, MATLAB is performed to compile the corresponding optimization algorithm and combines with ANSYS to carry out the inverse measurement. Finally, a practical illustration is curried out to determine the constitutive relations for some metals. The results clearly show that the imprint profile can significantly improve the identified accuracy of material constitutive relation.