Abstract: In order to optimize the NVH performance for roof,firstly,based on the plate-beam structural dynamics theory,the dynamic model of roof structure was established,and its calculation formula for natural frequencies is obtained.Secondly,study respectively the impact on dynamic characteristics due to changing of aspect ratio of roof reinforced beam and plate-beam thickness ratio.And then uses the structural topology optimization and the modal strain energy analysis technology,obtained the sensitive structures of a car roof for bend vibration modal.Finally,synthesize the roof dynamic mechanics theory and the car body modal characteristics,puts forward reasonable optimization schemes for NVH performance,which can provide theoretical basis and scheme for the roof structure optimization.

Key words: roof, NVH performance, plate-beam structural