Detection method for identifying material static mechanical property parameters in different areas of solder joints

A technology of static mechanics and detection methods, applied in the direction of testing the hardness of materials, etc., can solve problems such as not found, and achieve the effect of overcoming technical bottlenecks, high practical value, and strong engineering use value

CN102313676BInactive Publication Date: 2013-01-02HUNAN UNIV
5 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2013-01-02
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

A detection method for identifying material static mechanical property parameters in different areas of solder joints comprises the following steps of: (1) preparing a solder joint sample used for a hardness test; (2) selecting a plurality of points in the whole solder joint area along the direction of the solder joint diameter to carry out the hardness test, and regionalizing according to hardness number; (3) carrying out an indentation test in the regionalized areas to obtain a load-depth curve of different test points; (4) establishing a finite element model of the indentation test and verifying; (5) forming optimization mathematical models in different areas of the solder joints according to a simulation result of the finite element method numerical model in the indentation test and acorresponding experimental result; (6) calculating the static mechanical property parameters in different areas of the solder joints by the combination of genetic algorithm. The detection method provided by the invention has a simple principle, is convenient to operate, and can be used to determine local mechanical property parameters of a material with millimeter even micrometer dimensions and expand the application range of the indentation test.
Need to check novelty before this filing date? Find Prior Art

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 were ignored in the previous research on this aspect, that is, the base metal was directly used in the finite element numerical modeling of the welding area. Nodal connection or rigid connection, i...

Examples

Embodiment Construction

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] Since the constitutive relationship of most engineering polycrystalline metal materials conforms to the power exponential relationship, that is, the hardening curve approximates a parabolic shape. Similarly, for engineering structures formed by a sharp annealing process of cubic lattice metals (steel plates and aluminum alloys, etc.) like solder joints, there is also a parabolic tensile change curve in the plastic deformation stage, so the calculation used in the embodiments of the present invention The elastoplastic constitutive model of the material is represented by the Hollomon power exponent hardening equation, as shown in formula (1):

[0031] σ = K ϵ n = σ y ϵ y ...