Topology optimization of compressor mounts for minimizing dynamic compliance in a wide frequency range

This paper proposes a new structural design method to obtain an optimized shape of a compressor mount in a wide operating range. To eliminate the resonant frequencies of the structure in the wide operating frequency range, maximization and minimization of the natural frequency are performed simultaneously, and it is important to define an objective function that can derive a clear structural shape in both optimization cases. In this study, a multi-objective optimization method is proposed that combines dynamic compliance at sub-frequencies as well as at target frequencies to obtain an optimized structure, sufficiently clear to be applied for manufacturing while achieving the desired frequency response. The sub-frequencies are selected near the natural frequencies generated within the operating frequency range and are used to reduce the number of gray-scale elements and to prevent the creation of discontinuous structures. The material properties without the damping coefficient SIMP method are used and the frequency response of the structure is calculated using the mode superposition method. The proposed optimization method is applied to the natural frequency minimization problem of a cantilever, which was mentioned in previous studies as being difficult to derive a clear structural shape, to confirm its effectiveness, and a compressor mount design problem simply modeled in two dimensions is introduced.