Nondestructive testing system and testing analysis method for three-dimensional braided composite material

Abstract

The invention provides an acoustic-emission-technology-based nondestructive testing system and an acoustic-emission-technology-based nondestructive testing method for a three-dimensional braided composite material. In the method, an acoustic emission signal generated by the composite material under external loading is received by an acoustic emission sensor and then is digitized, and the damaged condition of the material is further analyzed. By the method, a unilateral stretching experiment of the carbon fiber three-dimensional braided composite material is dynamically monitored all the way by the acoustic emission technology; and the method proves that the number of the acoustic emission events has good correlation with damage evolution of the carbon fiber composite material; through the spectrum analysis of the carbon fiber three-dimensional braided composite material, the final damage to the material is caused by fibrous fracture and damage frequencies show the damage characteristics of the material; different types of damage modes are well described through the spectrum analysis, and frequency ranges of all peak values can be detailed further, so that more detailed explanation for damage types and mechanisms can be given; and the fracture modes of the material can be analyzed by using acoustic emission characteristic parameters.

Description

technical field [0001] The invention belongs to the field of testing and analyzing the measured object by applying external force by means of the physical properties of the measured material, and in particular relates to a non-destructive detection method of three-dimensional weaving composite material based on acoustic emission technology and a system for realizing the method. Background technique [0002] Defect detection of composite materials is to test and evaluate the performance of composite materials without changing the structure of composite materials. For different defects and damage forms, different non-destructive testing methods can be used. At present, the commonly used methods for non-destructive testing of composite materials are X-ray, ultrasonic, computer tomography (CT), infrared thermal imaging detection, acoustic emission, microwave, laser detection, neutron photography, percussion and ultrasonic detection. Wait. [0003] The detection accuracy of X-r...

AI Technical Summary

Problems solved by technology

At present, the mechanical analysis of 3D braided composite materials at home and abroad mostly uses testing machines to analyze the overall performance, but less research has been done on microscopic deformation, and the manufacturing process of 3D braided composite materials is extremely complicated, and there are few tested materials.

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