Uniform stress criterion-based bonding structure fracture failure analysis method

Abstract

The invention discloses a uniform stress criterion-based bonding structure fracture failure analysis method, which is characterized by comprising the following steps of 1, carrying out the quasi-static tensile tests on the bonding joints with different tension-shear ratios to obtain the initial failure loads and the initial failure areas of the bonding joints with different tension-shear ratios, 2, establishing a finite element model of a bonding joint with the same test size and different tension-shear ratios, and applying the initial failure load to a position, corresponding to the initial failure area, in the finite element model to obtain an initial failure point and initial failure stress, 3, obtaining the equivalent forces of the bonding joints with different tension-shear ratios ina complex stress state, and 4, establishing a finite element model of the bonding joint needing to be subjected to fracture failure analysis, applying the one-way stress, when the stress is greater than or equal to the maximum equivalent stress, starting to fail the glue layer of the bonding joint, determining a failure unit, deleting the failure unit, and recording the corresponding failure stress.

Description

Technical field [0001] The invention belongs to the field of evaluation of fracture failure of an adhesive structure, and specifically relates to a fracture failure analysis method of an adhesive structure based on a unified stress criterion. Background technique [0002] At present, with increasingly stringent requirements for automobile fuel economy and emission performance, in addition to the development of new energy vehicles and high-efficiency engines, reducing the weight of the body structure is also an important technical way to achieve energy saving and emission reduction. The multi-material body can not only significantly reduce the weight of the body but also improve the performance of the body, which will be the development trend of the body structure in the future. The connection of dissimilar materials in multi-material car bodies has become one of the key technologies to be solved urgently. As a new connection method, bonding technology can realize the connection ...

AI Technical Summary

Problems solved by technology

These failure criteria are established by dividing the fracture load by the bonding area under pure tension and pure shear states, but usually the stress distribution in the adhesive layer is not uniform and the stress components are not unique, but the normal shear stress exists at the same time, so These failure criteria are not accurate

In addition, due to the lack of fracture failure analysis methods specifically for bonded structures under complex stress states, bonded structures are currently mainly used on non-load-bearing structural parts with little stress in the car body, which limits the application of bonded structures in engineering. further application

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