A Method for Obtaining the Uniaxial Stress-Strain Relationship of Materials by Compression of Disk Specimen

Abstract

The invention discloses a method for obtaining the uniaxial stress-strain relationship of a material by compressing a disk sample. A hard alloy processing compression fixture is used to compress a disk sample with a moderate thickness to obtain its continuous load-displacement curve, and a power law is adopted. Fit the load-displacement curve (non-linear segment), and bring the fitted characteristic load and displacement exponent into equation (2) to obtain its uniaxial stress-strain relationship. The invention is applicable to ductile and power-law isotropic strengthening materials, can obtain stress-strain relationship curves of various ductile materials, and can design sample size according to the actual situation of the test material, and the sample can be as small as millimeter and micron, flexible It is convenient and overcomes the shortcomings of the traditional uniaxial tensile test, which is limited by the large size of the material, and can also be used to test the high-temperature uniaxial stress-strain relationship curve of materials. This method has great advantages for the micro-force material testing of the constitutive relationship of small samples such as precious metals, light materials, and minimally invasive discs constructed in service.

Description

technical field [0001] The invention relates to the testing technology of mechanical properties of ductile materials, especially the field of testing mechanical properties of light, rare and micro-scale materials. Background technique [0002] The uniaxial stress-strain curve is the most basic physical relationship of materials. It is the basic mechanical relationship required for mechanical performance testing (such as fatigue, fracture) and finite element analysis of materials and structures, and for the optimal design and safety assessment of structural parts. is of great significance. Traditional testing methods are mainly to cut standard uniaxial tensile samples from raw materials or components, and the sample size belongs to the decimeter and centimeter level. With the widespread application of miniaturized, lightweight components and expensive advanced materials and the development of minimally invasive sampling technology for service components, material testing bas...

AI Technical Summary

Problems solved by technology

With the widespread application of miniaturized, lightweight components and expensive advanced materials and the development of minimally invasive sampling technology for service components, material testing based on nano-specimen (millimeter, micron level) has begun to receive attention. In addition, in aerospace, nuclear power In such projects, there are a large number of welded structures and components with high stress gradients. It is difficult to obtain the mechanical properties of different areas (heat-affected zone, weld zone, etc.) by using traditional uniaxial tensile test methods. It becomes very difficult to test

Images