Simulation Research On The Acoustic Radiation Character For High Speed Train Floor Structure

China is making rapid progress in the manufacturing of high-speed railway; relevant technical skills has reached world standards. A number of studies have shown that, the interior noise of a high-speed train comes from its body panel, and sources of the interior noise of a high-speed train are mainly consisted of the two:vibration and transmission, respectively. This infers that, the interior noise of a high-speed train is mainly affected by the sound radiation efficiency and sound insulation performance of the train body panel. Designers now often manage the interior noise control of a high-speed train by using the method of "build a car body-run several tests-improve the structure." And in order to make the sound insulation performance of the structure meet the expected measurements, designers have to conduct multiple repetitive processes, which is quite expensive and time-consuming. One way to save time and money is to choose the simulation model. This paper uses the Acoustic FEM module in the LMS Virtual. Lab software to simulate the sound insulation performance of the high-speed train components. By using such simulation method, the paper hopes to predict the sound insulation performance of each designed component before it is manufactured. Also the paper hopes to apply these simulation results for possible design optimizations, which could reduce the time length and cost of a design cycle.First applied the direct acoustic-vibration coupling method to calculate the acoustic characteristic curve of a 1m*1m 0.01m aluminum plate. Then compared the calculated data with data obtained from reverberation chamber test on the simulation model of the same type of aluminum plate. In this way, the paper verifies the reliability of the simulation model.Secondly, the sound insulation quantity of a component varies by different structure. Therefore, the paper uses the LMS Virtual. Lab to build a model of "aluminum corrugated outside the floor-keel-sound insulation pad-sandwich plate" structure. In this model, working conditions varies as the system simulated the change of the sandwich plate thickness, the sandwich plate material, the interlayer thickness, the keel height and width, the sound insulation pad thickness, and the corrugated plate thickness. And each one-third octave band spectrum ranging from 100Hz to 3150Hz is calculated. By finishing this, the paper analyzes the sound insulation performance under different working conditions.Furthermore, the interior noise of a high-speed train is in the low frequency range(20-800Hz). This paper also analyzes the sound insulation quantity under different working conditions by calculating each narrowband spectrum (range from 200Hz to 800Hz) of the simulated working condition. To sum up, this paper studies influences of different working conditions to the sound insulation performance, and it gives possible parameters for future simulation tests.