Acoustic emission device and method for detecting destructive failure of carbon fiber composite material

Abstract

The invention discloses an acoustic emission device for detecting destruction failure of a carbon fiber composite material. The acoustic emission device comprises two sensors, a pre-amplifier, a band-pass filter and an acoustic emission detector, wherein the two sensors are respectively connected with the pre-amplifier; and the pre-amplifier, the band-pass filter and the acoustic emission detector are sequentially connected with each other. The acoustic emission device provided by the invention has the advantages of continuous real-time signal feedback, high sensitivity, convenient operation and the like, can dynamically extract and feed back the destructive failure information of the composite material in the loading process, can integrally detect and evaluate defect state of the entire composite material structure, and is suitable for early stage monitoring of the composite material structure or approaching failure characteristic prediction. Based on an amplitude-time diagram, an energy-time diagram, a counting-time diagram and an amplitude-position curve diagram acquired through acoustic emission detection, the method provided by the invention can accurately and rapidly determine dominant failure mode and failure mechanism of the composite material in each loading stage so as to provide technical support for deeply studying performance degradation mechanism of the composite material.

Description

technical field [0001] The invention relates to the research field of non-destructive testing and health monitoring of composite materials, in particular to an acoustic emission detection method for damage and failure of carbon fiber composite materials. Background technique [0002] Carbon fiber composite material is an advanced composite material widely researched and used at home and abroad. It is made of a number of fibers and matrix through physical and chemical methods. The components can "learn from each other" and "synergy". It has the advantages of high rigidity and strength, small specific gravity, good fatigue and fracture toughness, which are not available in general metal materials, and has been used in aerospace, pressure vessels and pipelines, new energy and energy saving, wind power, automobiles, marine and Shipbuilding, civil engineering, sports equipment and other fields show superiority, and the application prospect is good. [0003] However, due to the c...

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Problems solved by technology

Because the composite material is microscopically inhomogeneous, the fiber / matrix dispersion is large, and there are various random defects inside the material (the main defects are: air holes, delamination, looseness, cross-layer cracks, interface separation, inclusions, poor resin curing and drilling damage, etc.), the generation, accumulation and expansion of micro-cracks inside the material will reduce the strength and stiffness of the material, thereby reducing the service life of the structure

The percussion detection method has simple equipment and convenient operation, but it is only suitable for on-site inspection of large composite material structures, and has low sensitivity to small defects; optical fiber strain sensor detection has a series of advantages, such as good stability, high reliability, high precision, and Interference, simple structure, etc., but expensive equipment, not suitable for routine detection

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