Stress resonance fatigue test method and test system for lightweight high-strength composite material

Abstract

The invention relates to a stress resonance fatigue test method and a test system for a lightweight high-strength composite material. The invention belongs to the technical field of composite materialresonance fatigue tests. The problems that in the prior art, fatigue damage caused by response of static response analysis to the structure under dynamic excitation is difficult to obtain a more accurate conclusion, and no resonance fatigue test method and test system for the light-weight high-strength composite material and the structure exist are solved. The test method comprises the followingsteps: applying a counterweight, and adjusting the resonant frequency; setting a random vibration frequency range and parameters needing to be recorded; and setting an acceleration root-mean-square value, carrying out a test in a mode of gradually increasing the vibration stress level, and fitting a fatigue life curve. The test system comprises a vibration test bench, a data acquisition and display recording system, a resonance fatigue test control system and an induction part. The method has important guiding significance for further expanding to C / SiC and other composite material structure resonance fatigue tests.

Description

technical field [0001] The invention relates to the technical field of resonance fatigue testing of composite materials, in particular to a stress resonance fatigue testing method and a testing system for lightweight high-strength composite materials. Background technique [0002] For a long time, the fatigue damage caused by vibration has been one of the important reasons for the structural and mechanical failure of aviation, aerospace, transportation and other equipment. The product structure will inevitably be subjected to various vibration loads during use, but in many cases the impact of vibration loads on structural fatigue is easily ignored, resulting in many failures and accidents, and huge losses; especially when the external excitation frequency is distributed in engineering When the natural frequency of the structure is near, the huge response caused by structural resonance is more likely to cause structural failure. [0003] In the past, the evaluation and calcu...

AI Technical Summary

Problems solved by technology

However, there is very little research on resonance fatigue tests and analysis methods for composite materials and structures, especially for new lightweight, high-strength, high-stiffness composite materials (such as C / SiC) that are increasingly widely used in military equipment and civilian product structures. , is rarely involved

However, composite materials are quite different from metals due to material characteristics, processing methods, etc., resulting in material uniformity, response characteristics to stress, failure mechanism and form, etc., which are completely different from metals. Test methods for metals (mainly constant Stress) cannot meet the requirements of composite material resonance fatigue test

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