Method for detecting mechanical property of self-piercing riveting joint

Abstract

The invention relates to a method for detecting the mechanical property of a self-piercing riveting joint. A system adopted for the method comprises a riveting test piece, a material mechanical property testing device, an electron microscope, an image collection card, an image analyzing and processing system and the like. The double-riveting-joint test piece is designed. Image sequences produced before and after deformation occurs in an internal lock area in a riveting and fastening machine are obtained through an image observing system composed of the electron microscope. Before a load is exerted on the test piece, template images are selected inside a plane area formed by an angular section cutting plane of a rivet and outside the plane area respectively. Single images in the image sequences are analyzed and calculated in the deformation process through a correlational analysis method, target images corresponding to the template images are obtained through matching and by using the largest correlation coefficient, and the slide characteristic quantity of an internal lock of the riveting and fastening machine for the self-piercing riveting joint is obtained by calculating the relative slide amount between the template images and the target images. Therefore, the quality level of the self-piercing riveting joint can be comprehensively evaluated, and the scientific basis is provided for relevant research, design, crafting and the like of the self-piercing riveting joint.

Description

technical field [0001] The patent of the present invention relates to a method for testing the mechanical properties of metal components, in particular to a method for testing the mechanical properties of self-piercing riveted joints. Background technique [0002] Self-piercing riveting is a new type of cold-press embedded riveting connection method for thin plate materials. During the plate connection process, a semi-hollow rivet is pressed into the plate through a punch, and the end of the rivet tube leg is turned around to form a rivet buckle during the process of being embedded in the plate. The mechanical internal lock realizes the connection of multi-layer panels without destroying the overall strength of the lower panel. Self-piercing riveting connection technology has the characteristics of simple process and high connection strength. It occupies an important position in the field of automotive lightweight design and manufacturing. It is known as the next-generation ...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is that in the process of testing the mechanical properties of traditional self-piercing riveting joints, it is impossible to extract the characteristic quantity of the internal lock slippage of the riveting machine under the load of self-piercing riveting joints, so a method based on image analysis and processing is proposed. Testing method of mechanical properties

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