Ultrasonic Testing Of Carbon Fibre Reinforced Composites Based On Wavelet Analysis

More and more carbon fibre reinforced composites are used in manufacture of planes, automobiles, ships, etc. They recently replace most conventional materials in many areas. They are the particularly important in those areas such as navigation, naval ship and structure of nuclear energy. As it is known that the composite components may have defects in manufacturing which can induce huge losing and harm. However, most of these defects are invisible duo to unstable production techniques, i.e., materials'landscape bearing and contradict shearing strength are all too little to make material intact. Therefore, detects in materials must be detected in any time.In this thesis, wavelet analysis is used in nondestructive detection of carbon fibre reinforced composites combined with ultrasonic testing. It goes as:First, composite materials, nondestructive detecting and ultrasonic testing are presented. Their current situation and expected development are analyzed. At last, outline of the research task and process is proposed.Next, the equipments applied, principles and theories used in the experiment are introduced.So, a calculating formula to determine the defect location is put forward and its resolution to practical realization is presented.And then the principle of wavelet transform, and MATLAB system are introduced and their synthesis to application is presented.Finally,the acquisition of detected signals is presented, and the determination of detect severity is analyzed.The closing shows the summary and conclusions. At last, problems existed in the research is analyzed and the future work in the area is suggested.