Laser Ultrasound Study in Nondestructive Inspection of Composite Materials

• Main Authors: Yi-Cheng Lan, 藍怡成
• Other Authors: Che-Hua Yang
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/ftm4qt

碩士 === 國立臺北科技大學 === 製造科技研究所 === 104 === With the development and increased usage of composite materials, the safety requirements of the products also relatively increased. In order to ensure the safe use of composite products, the composite materials in the strength and defects on the detection of attention is gradually paid attention to. Compared to the use of destructive testing methods, the use of non-destructive testing technology for product quality testing is more advantages and fast. Resin based composites, have functions of load transfer, fiber protection, preventing damage on appearance of product, also need to have certain properties to resist and prevent growth of cracks. During the manufacturing process, the porosity of the resin based composites is the most common micro defects, which has a great influence on the strength and safety of the material. This research focuses on the matrix of the composite (resin) and resin-based composite with different porosity content of woven composite laminates, by using laser ultrasound technique for measurement, to get the resin matrix of guided wave dispersion relations. The differences in porosity of the specimens were fabricated by different process conditions and the variation of the dispersion curves under different porosity was observed. The experimental results show that for different thickness of pure resin specimens, the elastic modulus and thickness of two variables are inversed, thickness and the actual amount of measuring the thickness data has the error of 5%; In material parameters, compare the inversed result of elastic modulus and the actual use of the tensile test, the error is less than 12%. The shifting of dispersion curves at different porosity are also observed. Through this research, the adjustment of the process parameters can be more rapid in the process of the polymer material strength and porosity.