• Solid Mechanics •

SPHERICAL INDENTATION METHOD TO DETERMINE STRESS-STRAIN RELATIONS AND TENSILE STRENGTH OF METALLIC MATERIALS

Zhang Zhijie2)(), Cai Lixun3)(), Chen Hui4)(), Bao Chen, Liu Xiaokun

1. Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province, School of Mechanics and Engineering, Southwest Jiaotong University,Chengdu 610031, China
• Online:2019-01-18 Published:2019-03-01

Abstract:

It is significant to obtain the uniaxial stress-strain relations and tensile strength of materials by indentation method for evaluating the integrity of structures in service. Based on energy equivalent assumptions, i.e., the Von Mises equivalence about a RVE (representative volume element) and the median energy equivalence in the effective deformation region, a semi-analytical spherical indentation(SSI) model is proposed to describe the relation among indented load, depth, the diameter of spherical indenter and Hollomon-law parameters if indented materials are uniform, continuous, isotropic and power-law hardening. The stress-strain relations and tensile strengths of the materials were obtained by the tested load-depth curves under spherical indenter loading. Considering the damage effect in the indentation process, a correction model for determining elastic modulus of the metallic materials due to the spherical indentation tests is proposed . For eleven kinds of tested ductile metallic materials with spherical indentation, the Young's modulus, stress-strain relations and tensile strength predicted by SSI model are in good agreement with the uniaxial tensile results.

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