Cantilever bending load metal material fatigue damage test measurement method

Abstract

The invention relates to a cantilever bending load metal material fatigue damage test measurement method. According to a damage equivalence principle, based on a factor that metal material force application point displacement characteristic value is bound to change when fatigue damage occurs, with a material fatigue damage variable mathematical definition D=1-A' / A=(Delta A) / A, and through establishing a functional relationship between a smooth plate sample fatigue damage amount and the force application point displacement characteristic value, a restriction face (1), a notch (2), a cantilever zone (3), and a circulation load P force application point (4) are arranged on the smooth plate sample, such that the fatigue damage amount of the smooth plate sample can be monitored in real time. The fatigue damage amount is compared with a fatigue damage amount critical value, such that the safety and reliability of the service of the metal material or a metal component can be evaluated. The invention discloses the metal material fatigue damage quantitative test from one aspect, and provides a possibility for macroscopic measurement of metal material fatigue damage. The method has certain popularization value.

Description

technical field [0001] The invention belongs to the technical field of metal material fatigue damage, in particular to a test and measurement method for metal material fatigue damage under cantilever bending loading. Background technique [0002] During the smelting and forming process of metal materials, various micro-defects such as micro-voids, micro-cracks and micro-pores inevitably exist inside. Such micro-defects will be further derived and expanded under the action of fatigue load, making the material And the performance of the structure deteriorates, resulting in a decrease in the fatigue strength and remaining life of the component or structure, which poses a threat to the safe use of the engineering component or structure. In engineering, it is not uncommon for components or structures to undergo fatigue fractures due to the continuous action of cyclic loads on materials. The fatigue process is actually a process of damage accumulation. When the damage reaches the...

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Problems solved by technology

[0005] Fatigue damage of metal materials constitutes a serious threat to the safe use of engineering components or structures, and there are great difficulties in direct measurement from the microscopic level, and there is no report on the indirect measurement from the macroscopic level. The present invention is based on the equivalent of fatigue damage Combining with the mathematical definition of the material fatigue damage variable, the functional relationship between the material fatigue damage variable and the displacement characteristic quantity of the material application point is established through experiments, so as to realize the indirect measurement of the material fatigue damage from a macroscopic perspective, so as to provide engineering components Or the safety and reliability of the structure in service to provide an evaluation basis

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