Analysis And Calculation Of Sound Insulation Performance Of Double-Layer Board Of Body

In today’s automotive sector,light weighting of automobiles is particularly important.Reducing the thickness of the body panels or using lightweight new materials can reduce the weight of the car effectively,but the reduction in plate thickness will worsen the NVH performance of the car.The NVH performance of the car is an important performance of the car and must be guaranteed.Based on this background,it is especially important to improve the sound insulation performance by changing the double-layer structure of the vehicle body without increasing the weight,which is important for the lightweight and NVH performance of the car.At present,the research on the double-layer board is mainly the analysis of the theoretical or regular model,and the system research on the double-layer board of the automobile body is less.This paper uses experiment and calculation to study the sound insulation performance of the double-layer board of the car body,which has certain engineering significance.The experimental test method is used to qualitatively analyze the sound insulation performance of the double-layer panels of the car body.Four sets of representative double-layer boards are designed by referring to the size parameters of the multiple sets of body and the digital double-layer boards.The sound insulation curve of the scheme is used to analyze the influence of the structure of the double-layered body on the sound insulation performance of the double-layer board.In this paper,the perforated and trimming treatment of the designed tooling samples is carried out,and the perforated trimming is applied to the double-layer board of the vehicle body.The effect of acoustic performance on the sealing effect of acoustic sound insulation materials is studied.In addition,the effect of damping rubber on the sound insulation performance of double-layer panels is also studied.VA-One is used to calculate the sound insulation performance of the designed double-layer boards.The Hybrid FE-SEA method is selected to calculate the sound insulation performance,and the required parameter damping loss factor in the calculation is obtained by experiment.The calculation results are in agreement with the experimental values,which verifies the accuracy of the calculation method.The calculation method is used to analyze the factors affecting the sound insulation performance of the double-layer board.The damping loss factor of the double-layer plate,the constraint state,the number of solder joints,the size of the double-layer acoustic cavity,and the size of the bending protrusion are studied.And the conclusions obtained in the paper are used to improve the double-layer structure on a vehicle body.The improved double-layer board has a large increase in sound insulation under the premise of a weight loss of 10%,and the sound insulation of most frequency bands increases by 10 dB.