Optimization design on resonance avoidance for 3D piping systems based on wave approach

Vibration of liquid conveying piping systems in a closure may cause noising problem and degrade living comfort inside, it can even lead to fatigue failure of the system. Therefore, vibration alleviation in such circumstance is highly demanded. Traditionally, a piping system is designed to satisfy basic key functions as liquid conveying or heat exchange. Once the global arrangement of a piping system is determined for such key functions, local modifications with hangers on the piping system are then made to reduce its vibration. Here, we propose a method to optimize globally the shape and rigid hanger locations for a 3D piping system in order to achieve resonance avoidance. To this end, the wave approach is employed to estimate in a fast and accurate way the fundamental frequency of any 3D liquid conveying piping system, assembled from some basic elements. Based on genetic algorithm, optimization on shape and rigid hanger locations for a 3D piping system can be obtained with a maximal fundamental frequency, which is far away from the external excitation frequency. It shows that the shape optimization can be used to increase the fundamental frequency of a piping system if rigid hangers are not available, while the fundamental frequency can be increased more effectively with rigid hangers of optimized locations. Our work provides a systematic method for global optimization design of 3D piping systems.