Study On The Reliability Of CFRP Wound Pressure Vessels

Carbon fiber reinforced plastics (CFRP) are widely used in aerospace, marine engineering (such as all kinds of stratigic missile engine shells) and various civil applications due to their exceptionally high specific strength and specific module, good high-temperature resistance, corrosion resistance and so on. In recent years, the safety factor method has been used for the design of CFRP wound pressure vessels, which cannot explain the stochasticity and quantify scientifically the uncertain significant factors, has the disadvantages of low ecomony and so on. Under these circumstances, the study on reliability of CFRP wound pressure vessels during the winding technology process and inner pressure loading was accomplished in this paper.CFRP laminae, CFRP wound NOL rings and pressure vessels were manufactured, and different mechanical experiments and hydro-burst tests were performed. The experimental tests were conducted to obtain the probabilistic statistic distribution of design variables of CFRP wound pressure vessels (such as elastic constants, strength of lamina, winding technology parameters and the geometric sizes). And a goodness of fit test using the Kolmogorov-Smirnov method was used to get the best probabilistic distribution of design random variables. According to structural system reliability theory and composite structural mechanics, the limit state equation for reliability analysis of CFRP wound pressur vessels was set up. On the basis of experimental results, Monte Carlo numerical simulation procedure based on MATLAB was complied, which realize the reliability design and analysis for CFRP wound pressure vessels. The numerical simulation for the distribution of failure loads, probability of failure and the laws of the effect of significant random variables on probability of failure were performed. Good agreement was shown in the comparison between the simulation and experimental results."Reliability safety factor"of CFRP wound pressure vessels was obtained in the present study. It reflects not only the scienticity of reliability design, but also the...