Research On The Interlaminar Crack Image Detection Of The Carbon Fiber Reinforced Aluminum Matrix Composite Material

Carbon fiber reinforced aluminum matrix composite material which is referred to as Cf/Al composite material is widely used in automobile and aerospace fields,because of the advantages of higher strength,specific modulus,specific stiffness and other characteristics.However,since the Cf/Al composite material belongs to one of the laminated composite materials,so it has a common problem of the laminated composite materials,that is,the interlaminar micro crack can be easily produced in laminated composites under the impact of low energy,and the growth of the micro crack leads to the delamination between layers,which directly affect the safety of the whole structure.Therefore,it is very important to detect the interlaminar crack of the Cf/Al composite material.Because of the Digital Image Processing Technology has the advantages of high accuracy,the low cost,non-contact detection,the equipment is simple and easy to operate,many researchers at home and abroad have applied the digital image processing technology to the surface crack detection in recent years,which made the foundation to the method of crack image processing.Therefore,the paper proposed a quantification method of interlaminar crack image detection of Cf/Al composite material based on 2D image analysis via the MATLAB software,which provided a new method for the study of the interlaminar fracture behavior of Cf/Al composite material.The paper introduced the working principle of the interlaminar crack image detection system of Cf/Al composite material,and the related basic algorithms of digital image processing technology.The paper deeply studied the advantages and disadvantages of five image processing algorithms as follows: the binarization,region growing,morphological,edge detection and skeleton thinning.Based on the characteristics of the target,the paper improved these algorithms,then combined these algorithms with the MATLAB Programming designed a test software of the interlaminar crack image detection system of Cf/Al composite material,which was used to process crack image that was collected by SEM and X-ray in order to extract the length and the width of the crack.By comparing the calculated result with the measured result,verifying the accuracy of the test software in the paper.In this paper,the test software was optimized into a software system which was convenient for the users to operate.The optimized software system can process the crack image automatically according to the specified order of the image processing,and output the calculated result directly.The paper presented a new method to calculate the width of the crack when designed the software.The result can be obtained by calculating the distance between the two pixels that on the edge of the crack image.