Nano-silver sintered body shear deformation modeling method based on variable-order fractional derivative

Abstract

The invention discloses a nano-silver sintered body shear deformation modeling method based on a variable-order fractional derivative, and the method comprises the following steps: SS1, building a segmented fractional derivative viscoelasticity constitutive model according to the change of the viscoelasticity of a nano-silver sintered body in a shear deformation process; step SS2, describing the order change of the fractional derivative by adopting a linear function; step SS3, judging whether the nano-silver sintered body has a strain softening phenomenon or not according to the stress-straincurve; and SS4, establishing a variable fractional derivative viscoelasticity constitutive model, fitting experimental data, and determining model parameters. Aiming at the shear deformation of the nano-silver sintered body, the invention provides the variable-order fractional derivative constitutive model which is convenient to apply and clear in physical concept and can meet the precision requirement, so that the problem that the shear behavior of the nano-silver sintered body lacks a theoretical model is solved.

Description

technical field [0001] The invention relates to a shear deformation modeling method of a nano-silver sintered body based on variable-order fractional derivatives, and belongs to the technical field of shear softening modeling. Background technique [0002] In recent years, along with the growing information society's requirements for multi-function, high reliability, intelligence, and miniaturization of power electronic products, the requirements for heat resistance and pressure resistance of packaging materials are also getting higher and higher. In order to meet the high temperature requirements of electronic chips, people focus on the research of packaging materials that can withstand high temperatures, such as tin-based solder, silver materials, and the like. Because silver has good electrical and thermal conductivity, people began to focus on the study of nano-silver. As a promising material with excellent electrical and thermal conductivity, nano-silver can be sintere...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art, aiming at the shear deformation of the nano-silver sintered body, to provide a variable-order fractional derivative constitutive model with convenient application, clear physical concept and meeting the accuracy requirements. This solves the problem of the lack of a theoretical model for the shear behavior of nano-silver sintered bodies

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