A Quantitative Test Method for the Whole Process of Damage Evolution in Vibration Fatigue Test

Abstract

The invention relates to a damage evolution overall process quantitative test method in a vibration fatigue test; the method comprises the following steps: using a laser displacement sensor to synchronically record a displacement sinusoidal signal of a sample; using an accelerometer to synchronically record an exciting acceleration signal of a vibration test equipment table; using a phase difference discrimination method to accurately capture an inherent frequency of the sample in the vibration fatigue process, real time tracking and recording an inherent frequency changing process, thus realizing the damage evolution overall process quantitative test in the vibration fatigue test. The test method can online obtain the overall process of the sample from the damage start to the damage evolution in the whole vibration fatigue test full life period, is low on test equipment requirements, high in data accuracy, and large in data result reference meanings. The method can provide important application values for studying fatigue damage characteristics and fatigue life rules of materials and structures.

Description

technical field [0001] The invention is a quantitative test method for the whole process of damage evolution in a vibration fatigue test, which belongs to the technical field of mechanical property test. Background technique [0002] Fatigue failure is a common form of failure in engineering materials. Fatigue performance testing for engineering materials is of great significance for the design and life prediction of engineering structural parts. Vibration is a common form of motion in engineering structures, and it is also an important cause of fatigue failure of engineering structures and materials. Therefore, vibration fatigue testing is an important test method to obtain the fatigue performance of materials and structural parts under vibration conditions. [0003] During the fatigue loading process, it is of great significance to study the fatigue performance of materials and structures by in-situ observation of the fatigue risk zone of the sample to obtain the whole pr...

AI Technical Summary

Problems solved by technology

During the vibration fatigue test of the sample, the vibration frequency is usually relatively high (hundreds to several thousand Hz). Under the condition of such a high vibration fatigue frequency, it is difficult to realize the fatigue damage of the sample by using the method of online in-situ image observation. real-time collection of initial and damage evolution images. In addition, due to the high number of fatigue cycles required by the vibration fatigue test, usually up to 10 7 to 10 9 The number of cycles, the test cycle of a single sample may even be as long as tens of days, even if the image of the fatigue danger zone in the whole process of damage evolution can be collected, the image scale will be quite large, and there are very high requirements for image storage and processing. challenge

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