A new random interval method for response analysis of structural–acoustic system with interval random variables

•A structural–acoustic system with interval random variables is presented.•RM-CVISPM to predict the intervals of expectation and variance is deduced.•RM-CVISPM to predict the interval of probability density is deduced.•The effectiveness and efficiency of RM-CVISPM is verified.•Comparison between HRIM and RM-CVISPM is shown.

For the response analysis of the structural–acoustic system without sufficient information, an interval random model is introduced. In the interval random model, the uncertain parameters are assumed as random variables, while some probability distribution parameters of random variables are modeled as interval parameters instead of precise values. Based on the interval random model, the interval random dynamic equation is constructed and a new random interval method named as the random moment – change of variable interval stochastic perturbation method (RM-CVISPM) is proposed. In RM-CVISPM, the response of the structural–acoustic system is approximated as a linear function of interval random variables based on the first-order stochastic perturbation analysis. Then, the expectation and variance of the obtained response are calculated by the random moment method. The probability density of the obtained response is yielded by the change of variable technique. Finally, the intervals of expectation, variance and probability density of response are estimated by an interval perturbation method. Numerical results on a shell structural–acoustic model and an automobile passenger compartment with flexible front panel verify the effectiveness and efficiency of RM-CVISPM.