OS1521-163 インデンテーションにおける代表ひずみ速度の導入

Abstract

Indentation is commonly used to investigate the elastic and plastic properties of materials, which include strain rate dependence. In this study, in order to propose a new indentation concept, which involves the representative strain rate, a finite element method analysis based on the strain rate dependence of materials was used. In order to generate an index of strain rate within the indentation, a strain rate distribution averaging was performed. The strain rate distribution was averaged using the critical and representative strain boundary values of the indentation. It was determined that the relationship between the average strain rate and the loading curvature could be expressed using the dynamic constants of the Cowper-Symonds equation. This allowed for the development of a modified Kick's law that included the effect of strain rate in the indentation analysis. Furthermore, the average strain rate calculated using the representative strain could be defined as the representative strain rate for the indentation from the results of a parametric analysis. These results depended on the work-hardening coefficient and the indenter angle. Therefore, the representative strain rate, which revealed a new indentation parameter, was proposed