BIW Modal Analysis And Strucral Optimiztion Based On The NVH

In order to reduce the weight of the body, the complexity of the process, reduce costs, and meet the market requirements of vehicle comfort and improve the competitiveness of the automotive industry, the research and development of the body NVH performance become more and more important, and the essential of BIW NVH performance development is the BIW stiffness, quality, damping matching design.The main subject mainly uses the finite element method and boundary element method. Under the guidance of basic principle in noise and vibration of vehicle, white body CAD model as the foundation, the finite element model is established through the Hypermesh, MSC.nastran software as platform and analysis the model of stiffness and modal calculation to obtain reliable white body structure’s design parameters, the next step for the white body structure optimization goal and direction.By using the software LMS white bodywork modal analysis and validation, the white body in a few mode frequency and excitation frequency are found out they are relatively easy to produce resonance phenomenon. Body in white in a twisting or bending condition, because of insufficient stiffness have a larger deformation and white body NVH performance effect size and other issues, and on this basis to establish the body in white of constrained damping structure topology optimization model, based on the damping pad size, thickness and location optimization to improve the stiffness of BIW, reduce noise, reduce vibration and reduce of the weight. By the combination of lots of experiments ultimately, it is presented in the process of mathematical model based on the floor after the thickening or after floor increased beam white body damping structure optimum layout guidelines.