Abstract: In this paper, the structure system with multiple failure modes were classified into the system with single limit state function and the one with multiple limit state function, then, the general reliability models and expressions for the two structure systems were also established, respectively. Meanwhile, in view of the characteristic that the reliability of structure system with multiple failure modes was usually computed by approximate estimation method and the results of calculation had some errors, we put forward a new relatively accurate method to calculate the reliability of structure system with multiple failure modes based on the Monte Carlo simulation method in MATLAB, gave the detailed calculating steps and program diagrams, and proceeded analysis combining with two examples. The results show that the calculated reliability by using multiple failure mode are more scientific and precise, compared with that computed by traditional single mode. Furthermore, the low efficiency in conventional realization process by Monte Carlo simulation method can be overcome during the new reliability calculation by using computer programs directly, the results can be calculated without the linear of performance function and normalizing of random variable, without complex conversion process, without solving the joint probability density function, and can obtain high calculation accuracy.

Key words: multiple failure modes, reliability of structure system, general model, Monte Carlo simulation method, MATLAB