Porous material constitutive relation solving method based on nanoindentation theory

Abstract

The invention relates to the technical field of electronic packaging nanometer mechanical property testing, particularly to a porous material constitutive relation solving method based on a nanoindentation theory. According to the specific technical scheme, the method comprises the steps: carrying out indentation on a porous material matrix multiple times by using a nanoindenter to obtain a plurality of displacement-load curves, removing the curve with large error, carrying out average curve fitting on the rest curves to obtain an average curve, and taking the average elastic modulus of the average curve as an experimental elastic modulus E; then determining a characteristic stress sigma r, and determining a hardening index n according to a dimensionless function; determining characteristic strain epsilon r and yield stress sigma y; and finally obtaining a constitutive curve according to the hardening index n, the yield stress sigma y and the elastic modulus E. According to the method,the problems that in the prior art, material attributes and stress-strain curves are not in one-to-one correspondence, the number of iterations is large in the simulation process, and the consumed time is long are solved.

Description

technical field [0001] The invention relates to the technical field of nanomechanical performance testing of electronic packaging, in particular to a method for solving the constitutive relationship of porous materials based on nanoindentation theory. Background technique [0002] Nanoindentation technique is an effective method to evaluate the mechanical properties of coating and film materials. Indentation load and displacement diagrams, as an advanced micro / nanoscale mechanical testing technique, are widely used in the study of mechanical properties of materials. The nanoindentation response is essentially related to the stress-strain curves of elastoplastic isotropic materials through nanoindentation of different indentation types. The elastic modulus, hardness and plasticity of materials can be determined by indentation curves, usually existing Analysis methods based on finite element simulation can be divided into two categories: forward analysis and inverse analysis....

AI Technical Summary

Problems solved by technology

[0004] Aiming at the deficiencies of the prior art, the present invention provides a method for solving the constitutive relation of porous materials based on the nano-indentation theory, which solves the uniqueness problem that often occurs in the prior art, that is, material properties and stress-strain curves are not one-to-one The corresponding relationship, and the problem that the number of iterations in the simulation is large and the time spent is long

Images