Study On The Reliability Of Composites Overwrapped Pressure Vessel

Composite materials are widely applied in aerospace, marine engineering and various civil applications due to their exceptionally high specific strength and specific module, good high-temperature resistance, corrosion resistance and so on. The composites overwrapped pressure vessel, which has been used to replace the steel vessel abroad, has the advantages of high pressure, high fatigue life, light weight etc. In recent years, aluminum liner composites vessel is researched in China and used in more fields.The traditional design of structure and strength checking are based on deterministic method. The deterministic method, which uses the safety factor decided by experience to describe the effects of random uncertainty on the structure, doesn't solve the random problem. Therefore, the results have wide deviation with the actual situation. And the deterministic method has some disadvantages, such as strong subjectivity, bad scientificity, low economy etc. In recent years, applying the reliability analysis to the design and analysis of the composite structure is a new developed field. The reliability analysis, which considers the basic design parameters of the composite structure as random variables, is more scientific and reasonable. On the basis of considering the probabilistic distribution of each variable, the reliability method makes prediction and analysis of the structure's failure probability.In the paper, we took the reliability analysis upon the most common composites overwrapped pressure vessel. On the basis of determining the probabilistic distribution of design random variables, we used the Monte Carlo method to take the reliability analysis of the composites overwrapped pressure vessel, according to the combination of structural system reliability theory and composites structural mechanics. And the sensitivities of the design variables were evaluated based on the calculated results. Therefore, the paper provides a more appropriate method and science basis for the reliability design of the composites overwrapped pressure vessel.