Detecting method for identifying dynamic mechanical property parameters of materials in different zones of welding spot

Abstract

The invention discloses a detecting method for identifying dynamic mechanical property parameters of materials in different zones of a welding spot, comprising the following steps: (1) preparing a welding spot specimen for hardness test; (2) selecting a plurality of spots for hardness test in the entire welding spot zone in the diameter direction of welding spot test, and dividing zones accordingto hardness values; (3) carrying out dynamic indentation test in the divided zones to obtain a load depth curve of different test points; (4) establishing a finite element model of the indentation test and verifying; (5) constructing optimized mathematical models at different zones of the welding spot according to a simulated result of the finite element model of the indentation test and a corresponding test result; and (6) solving the optimized mathematical models in the step (5) by adopting an overall optimization algorithm to obtain dynamic mechanical property parameters of different zonesof the welding spot. The detecting method is simple in principle, convenient to operate and is capable of measuring the local dynamic mechanical property parameters of materials within the range of millimeter and even micrometer sizes. In addition, the application range of the indentation test is widened.

Description

technical field [0001] The invention mainly relates to the field of material detection in mechanical engineering manufacturing, in particular to a method for detecting mechanical property parameters of materials in solder joint regions. Background technique [0002] In the process of welding metal sheets, due to the influence of resistance heat, the material properties of the welding area will change, which makes the performance of this area different from that of the base material. According to the characteristics of hardness, the welding area can be divided into three sub-areas: Base metal zone, heat affected zone, solder joint zone. Since the size of the base metal is generally large enough compared with the heat-affected zone, the material properties of the heat-affected zone have been ignored in previous studies, that is, the common node connection is often used in the finite element numerical modeling of the welding zone It is obvious that the material properties at t...

AI Technical Summary

Problems solved by technology

However, when identifying and detecting material dynamic performance parameters such as solder joints that have non-uniform material properties in each area, the initial cross-sectional area A of each area to be tested 0 It is difficult to determine, therefore, the stress-strain relationship cannot be directly obtained according to the basic equation of the appeal through the dynamic indentation test, and the dynamic mechanical performance parameters of this area cannot be directly fitted

Images