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Effect of Equibiaxial Pre-Stress on Mechanical Properties Evaluated Using Depth-Sensing Indentation with a
Takashi Akatsu1, Yoshihide Tabata2, Yutaka Shinoda3
1Faculty of Art and Regional Design, Saga University, 2441-1 Oono-otsu, Arita-cho, Nishimatsuura-gun, Saga 844-0013, Japan.
Materials (Basel, Switzerland)
|January 21, 2023
Summary
Equibiaxial pre-stress (EBPS) significantly alters mechanical property evaluations. Compressive EBPS increases elastic modulus and yield stress, while tensile EBPS decreases them, impacting material deformation resistance assessments.
Area of Science:
- Materials Science
- Mechanical Engineering
- Solid Mechanics
Background:
- Accurate evaluation of material mechanical properties is crucial for engineering applications.
- Depth-sensing indentation is a common method for characterizing material behavior.
- The influence of pre-stress on indentation measurements requires further investigation.
Purpose of the Study:
- To investigate the effect of equibiaxial pre-stress (EBPS) on the measured mechanical properties using indentation.
- To analyze how EBPS influences the evaluation of elastic modulus and yield stress.
- To understand the underlying mechanisms of EBPS effects on material deformation resistance.
Main Methods:
- Numerical analysis using the 3D finite element method (FEM) to simulate indentation.
- Application of the depth-sensing indentation method with a point-sharp indenter.
- Quantification of elastic modulus (E*) and yield stress (Y*) under varying EBPS conditions.
Main Results:
- Both elastic modulus (E*) and yield stress (Y*) increased with compressive EBPS and decreased with tensile EBPS.
- The observed changes in E* and Y* were nominal, with insignificant alterations in indentation pile-up or sink-in.
- The effect of EBPS on E* aligned with Hooke's law for elastoplastic materials, while the effect on Y* related to changes in von Mises stress.
Conclusions:
- Equibiaxial pre-stress significantly impacts the apparent mechanical properties derived from indentation tests.
- The study provides a quantitative understanding of how pre-stress affects elastic and plastic deformation resistance.
- Findings are essential for accurate material characterization in pre-stressed components.
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