First Order Analysis for Automotive Body Structure Design - Part 4: Noise and Vibration Analysis Applied to a Subframe

First Order Analysis (FOA) is useful for designing subunits in the mid-frequency range, as the layout and mounting positions can easily be decided at the conceptual design phase. In order to reduce vibration, we propose FOA for Noise and Vibration (NV) with the following characteristics. First, a dynamic beam element is formulated analytically using Euler's beam theory [1], so that a long uniform beam can express one element with high-order vibration. Second, power flow between potential energy and kinetic energy can be expressed as post-processing, so we can examine how to change or cut off the vibration energy path. In this paper, the above analysis is applied to a front subframe for the conceptual design of an automotive body structure.