Reliability-based topology optimization for optimal muffler design considering uncertainty

摘要

A reliability-based topology optimization (RBTO) is employed for obtaining an acoustically optimal partition layout inside a muffler. A partition volume minimization problem is formulated by using an acoustical topology optimization method and a reliability design concept. A finite element model is used for acoustical analysis and reliability analysis. One design variable is assigned to each node and determines the acoustic properties of an associated finite element. Since the acoustic material properties, such as the density and the speed of sound, of acoustic medium change with the operating condition of noise sources, they are defined as random variables. In the reliability-based acoustical topology optimization problem, the partition volume inside the design domain of an expansion chamber muffler is selected as an objective function. A transmission loss value at a target frequency and the reliability of the transmission loss changing with operating condition in consideration are constraints. Acoustical analysis is carried out by using a commercial finite element analysis program, COMSOL Multi-physics 5.2. A gradient-based optimizer, MMA (Method of Moving Asymptotes), is used to solve the formulated topology optimization problem. The first order reliability method and the Monte Carlo simulation method are used in a design process and a verification process, respectively.