Detection method for identifying static mechanical performance parameters of materials in different regions of weld joint

Abstract

The invention relates to a detection method for identifying static mechanical performance parameters of materials in different regions of a weld joint, which comprises the following steps of: (1) preparing a test piece of a weld joint indentation test; (2) selecting a plurality of points to carry out hardness test in the whole weld joint region of the test piece in the vertical weld joint direction and carrying out reasonable partitioning according to an obtained hardness value; (3) obtaining load-depth curves of different regions; (4) establishing an indentation test finite element model andcarrying out verification on the accuracy of the finite element model; (5) forming a target response function mathematical optimization model in different regions of the weld joint according to an analog result of the indentation test finite element model and a corresponding experimental result; and (6) combining an optimization genetic algorithm and carrying out iteration according to selected target response functions to obtain optimal solutions so as to obtain the static mechanical performance parameters in different regions of the weld joint. The detection method has simple principle and is convenient to operate. The local mechanical performance parameters of the materials in the range of millimeter even micrometer can be measured. The application range of the indentation test is expanded.

Description

technical field [0001] The invention mainly relates to the field of material detection in mechanical engineering manufacturing, and particularly relates to a method for detecting mechanical property parameters of materials in a welded seam area. 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 metal. According to the characteristics of hardness, the welding area can be divided into three sub-areas: Base metal zone, heat affected zone, weld zone. Since the size of the general base metal is large enough compared with the heat-affected zone, the material properties of the heat-affected zone have been ignored in previous researches on this aspect, that is, the base metal is directly used in the finite element numerical modeling of the welding area. Nodal connection or rigid connection, obv...

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Problems solved by technology

In the previous research work on obtaining material parameters through indentation tests, whether it is for traditional metal materials or new materials such as foamed metals, it is based on the uniform distribution of these material parameters. Detection of material parameters of engineering structures, such as weld areas, where material properties are characterized by continuity and inhomogeneity, is rarely reported in the literature

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