Improved type breakage failure stress testing method of adhesion test piece

Abstract

The invention discloses an improved type breakage failure stress testing method of an adhesion test piece. The improved type breakage failure stress testing method comprises the following steps: 1, performing quasi-tensile test on n adhesion abutting joints with different adhesive layer thicknesses to acquire initial breakage failure loads and initial breakage failure points of the n adhesion abutting joints; 2, building finite element models of the adhesion abutting joints of which the test sizes are identical and the adhesive layer thicknesses are different, applying the initial failure loads into the finite element models to ensure that an application position corresponds to the quasi-tensile test to acquire the breakage failure stresses of the unit corresponding to the initial breakagefailure points, wherein the failure stress comprises components, including sigma 1, sigma 2 and sigma 3, of three main stresses; and 3, acquiring the breakage equivalent stresses of the adhesion abutting joints with different adhesive layer thicknesses under complicated stress states. According to the improved type breakage failure stress testing method disclosed by the invention, the initial failure stresses of the adhesion abutting joints can be determined, the breakage equivalent stresses is determined, a real failure process is approached relatively, and the correctness of a breakage failure analysis process of an adhesion structure is improved.

Description

technical field [0001] The invention relates to the field of testing mechanical properties of bonded structures, and more specifically, the invention relates to an improved test method for fracture failure stress of bonded specimens. Background technique [0002] With the increasingly widespread application of lightweight materials such as composite materials on car bodies, bonding technology has been used more and more for its advantages of uniform stress distribution, light weight, and high strength. However, due to the lack of understanding of the mechanical properties of bonding structures Insufficient, so that the application of adhesives in many critical structures is limited. As the weak link of the bonded structure, the bonding area is the key to realize the weight reduction of the car body by using light materials to accurately understand its strength. [0003] In order to make the strength of the bonded structure better meet the use requirements of engineering pro...

AI Technical Summary

Problems solved by technology

However, in theory, when the material type of the adhesive and the substrate is fixed, the adhesive fracture failure stress, as the evaluation criterion for adhesive failure, should not change with the change of the adhesive thickness, so different fracture failure stress values ​​will be obtained. , it is very likely that the bonding thickness affects the distribution of various stresses on the adhesive layer, resulting in a change in the stress that causes the final failure of the adhesive layer, so that the bonded specimen with a large thickness there was destruction

[0004] Due to the limitations of the existing test methods for the strength of bonded specimens, the experimental test results cannot truly reflect the actual strength of the bonded structure. Conduct improved research to find a more accurate and practical test method for fracture failure stress of bonded specimens

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