Testing device and method suitable for non-standard multi-element compound fatigue fracture

Abstract

The invention discloses a testing device and method suitable for non-standard multi-element compound fatigue fracture, and belongs to the technical field of compound fatigue fracture testing. The device comprises an upper clamp, a lower clamp, an auxiliary clamp, a self-adaptive support, a composite crack propagation sample, and matched and customized screws for fixing the auxiliary clamp and corresponding upper and lower clamps and a plurality of positioning bolts and nuts. According to the invention, I type, II type, III type and I-II compound type, I-III compound type and II-III compound type fatigue fracture experiments with different compound ratios can be realized by replacing the auxiliary clamp; meanwhile, the fatigue fracture test of samples with different thicknesses can be realized by adding the self-adaptive supporter, the assembly precision of the samples and the device is reduced by using the self-adaptive supporter, and the problem of composite crack size effect test research is also solved. And by using the auxiliary clamp and the self-adaptive support, the whole device is convenient and rapid to operate, economical and practical.

Description

technical field [0001] The invention discloses a test device and method suitable for non-standard multi-element composite fatigue fracture, belonging to the technical field of composite fatigue fracture testing. Background technique [0002] Fatigue and fracture is one of the common failure modes of mechanical parts, and it is also one of the most serious failure modes. Due to the asymmetry of the load on the engineering structure, the randomness of crack generation and the anisotropy of materials, the cracks in actual engineering components are often not of a single type, and the stress field near the crack tip contains both types I and II. The stress of type III and type III cracks, that is, the cracks in the structure, often show a composite state. [0003] The crack tip field and fatigue fracture behavior of composite cracks are affected by uncertain factors such as sample material, geometric size, stress state, and loading form, and the existing experimental research c...

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Problems solved by technology

[0004] Composite crack types include composite cracks such as I-II, I-III, and II-III. The experimental research of each composite crack requires a corresponding loading fixture, and the material cost and processing cost are relatively high.

Moreover, the size effect factor of the fatigue fracture problem cannot be ignored. If the size effect is considered, a number of loading fixtures are required, which greatly increases the test cost.

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