Low frequency noise caused by vibrating panels can become a problem for vehicles from NVH standpoint. The vibro-acoustic analysis of a simplified vehicle model is presented in this study. Analysis of vibro-acoustic behavior includes frequency response analysis of structure by Finite Element Method (FEM) and sound pressure level (SPL) prediction of the cabin interior by Boundary Element Method (BEM). The structural design of the vibrating panels can be modified by adding stiffeners to improve the acoustic field inside the cabin. The dynamic analysis of the structural model must be repeated after every modification which will be a time consuming process in the design stage. In this study, a methodology that utilizes the frequency response functions (FRFs) of the original model for the reanalysis of the structure that is subjected to structural modification is adapted. Modal analysis of the original structure is performed only once to obtain the receptance values. Then, the structural modification method is used to calculate the receptances of the modified system. The structural modification method uses the receptances of the original system and the dynamic stiffness matrix of the modifying part of the structure. The response of the structure obtained from receptances of the modified structure is then used to supply vibration data as boundary condition for acoustic analysis of the cavity for SPL prediction at desired points
