Indentation based measurement of residual stress and plastic properties with gradient distribution

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420025
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Chuo University
• Principal Investigator: YONEZU Akio 中央大学, 理工学部, 教授 (40398566)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 材料強度 / 塑性ひずみ / 残留応力 / 有限要素法 / インデンテーション法

Outline of Final Research Achievements

This study proposed a method to evaluate the residual stress and plastic properties using micro-indentation test. This method deals with the materials that obeys the Ludwick work hardening law and involves in-plane equi-biaxial residual stress. Numerical experiment with finite element method (FEM) was carried out in order to simulate indentation test having various plastic strain and residual stress. It was found that indentation force increases with the increasing in plastic strain as well as compressive residual stress. Next, parametric FEM study by changing of residual stress and plastic strain was conducted in order to deduce relationship between indentation curve and materials parameters. This relationship can be expressed by dimensionless function with simple formulae. Thus, the present method can estimate plastic strain (plastic properties) and residual stress for various materials, such as stainless steel, engineering metallic and polymers.

Free Research Field

材料力学