Extension of experimental statistical energy analysis to structural vibration with low modal density

Abstract

Statistical energy analysis (SEA) is a method for understanding energy transfer paths related to vibration noise generation. In SEA, a target object is separated virtually into subsystems among which the transfer of vibration energy can be quantified. Conventionally, SEA is applied to structures that comprise thin plates, such as the bodies of large ships. The structure is then designed so that the transfer of vibration energy is varied to avoid energy being concentrated on any one subsystem. Although SEA is an effective method for preventing vibration noise problems, it becomes critically inaccurate when applied to structures with low modal density. This paper is aimed at clarifying an appropriate measuring process for constructing SEA models with two subsystems that provides high accuracy for structures with arbitrary modal densities. Evaluations of three simplified structures with different modal densities are conducted to determine how to improve the conventional measurement method.

Keywords

• noise
• vibration
• sea
• measurement
• modal density