Detection method for identifying dynamic mechanical property parameter of different area materials in weld joint

Abstract

A detection method for identifying dynamic mechanical property parameters of different area materials in a weld joint comprises the steps of: (1) preparing a weld joint test piece for an indentation test; (2) selecting several points in a whole weld joint area perpendicular to the weld joint on the test piece to carry out a hardness test, and carrying out reasonable partitioning according to the obtained hardness number; (3) carrying out dynamic indentation tests on the partitioned areas to obtain load-depth curves of different areas; (4) establishing dynamic indentation test finite element models; (5) forming target response function optimized mathematic models of different areas in the weld joint, according to simulate results of the indentation test finite element models and corresponding experiment results; (6) combining an optimized genetic algorithm and carrying out iteration with the target response functions to obtain dynamic mechanical property parameters of different areas in the weld joint. The invention with a simple principle and convenient operation can determine material local mechanical property parameters in a millimeter even micrometer dimension scope, so as to expand application scope of the indentation test.

Description

Technical field [0001] The invention mainly relates to the field of material detection in mechanical engineering manufacturing, and particularly refers to a method for detecting mechanical properties of materials in the weld zone. Background technique [0002] In the process of welding metal plates, due to the influence of resistance heat, the material characteristics of the welding area will change, which makes the dynamic performance of this area different from the base material. According to the characteristics of hardness, the welding area can be divided into three sub-regions. : Base metal zone, heat affected zone, weld zone. In the previous analysis on this aspect, since the size of the general base material is large enough compared with the heat-affected zone, the heat-affected zone can be ignored, that is, the welding area adopts common node connection or rigid connection when performing finite element numerical modeling. This modeling method cannot consider the material...

AI Technical Summary

Problems solved by technology

However, when identifying and detecting the material dynamic performance parameters in different areas of the weld, the initial cross-sectional area A of the weld area to be tested 0 It is difficult or even impossible to determine. Therefore, the stress-strain relationship in this area cannot be deduced through dynamic indentation tests, which directly leads to the inability to obtain the exact dynamic mechanical parameters of this area through conventional fitting methods.

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