A thermal vibration fatigue test device and method for composite materials based on reverse resonance

Abstract

A reverse resonance-based composite material thermal vibration fatigue test apparatus and method. The test apparatus comprises a double cantilever beam vibration test system, a thermal environment simulation system, an electronic acquisition system, and a measurement and control system. Eccentric motors (3) are used for driving beams to be tested (12) to vibrate. With respect to the use of a vibration exciter, the apparatus has a smaller volume, consumes less energy, and is convenient to carry. The reverse resonance of double cantilever vibration beams (2) is used for driving the beams to be tested (12) to vibrate, thereby improving test efficiency and saving energy, and compared with the existing test apparatus, the amplitude range of the beams to be tested (12) is widened. According to the apparatus and method, are the fatigue characteristics of a material to be tested are measured and analyzed in multiple aspects such as optics, acoustics, and time-domain waveforms using a variety of precision instruments, thereby achieving high test accuracy. Moreover, the thermal environment of a composite material can be simulated, and the fatigue characteristics of the composite material at different temperatures can be tested. The apparatus is simple, and the components are designed to be detachable. The apparatus is convenient to disassemble, portable, and easy to operate.

Description

technical field [0001] The invention belongs to the technical field of composite material structure fatigue testing, and in particular relates to a thermal vibration fatigue testing device and method for composite materials based on reverse resonance. Background technique [0002] As we all know, thermal fatigue refers to the uneven temperature distribution of materials in the environment of temperature changes. Due to the different expansion degrees, the deformation of different parts is restrained, and cyclic thermal stress or thermal strain is generated inside the material, resulting in crack initiation and propagation. , the eventual phenomenon of material failure. With the rapid development of various fields, the performance enhancement indicators of various materials are increasing day by day, and the damage caused by thermal fatigue is increasing day by day. Composite components are often damaged or even destroyed due to stress and environmental factors (especially t...

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Problems solved by technology

For example, patents CN 105758758 A, CN107917797 A, and CN 207197971 U all use water cooling as the cooling method. The cooling speed of the water cooling method is fast, but it is not easy to control and it is easy to oxidize the surface of the cooling object, and the water cooling will cause a larger temperature difference inside the sample. , may lead to greater thermal stress, which will make the conditions of the thermal fatigue test different from the actual ones. Therefore, water cooling is not suitable for thermal fatigue analysis of composite materials, while air cooling uses air as the cooling medium, which is energy-saving, environmentally friendly, space-saving, stable and reliable. Features, which have broad prospects in the field of thermal fatigue testing, suitable for thermal dynamic fatigue testing of composite materials

[0006] Common fatigue testing machines include hydraulic servo type, electromagnetic type, and mechanical type, but none of them are suitable for research on the thermal dynamic fatigue performance of composite materials. For example, the patent CN 106680120 A adopts an electro-hydraulic servo type method, which is tested by hydraulic control. It makes the test cost high, the power consumption is large under the low-frequency working state, and the test cost is high

For example, the patent CN104990820 A adopts the electromagnetic method, which is suitable for high-frequency working conditions and is mainly used for testing ferrous metal components with good fatigue performance, but the effect on samples with general fatigue performance is poor

For example, the patent CN 208239229 U adopts a mechanical method, which has a small scope of application and is suitable for fatigue tests with low frequency requirements, and cannot be adjusted

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