Noise Barrier Was Analyzed Under Impulsive Wind Load

High-speed trains generated noise serious harm to people’s health, set sound barrier along the line can be as a solution to the noise in an effective way, the safety need to pay attention also. Based on the software ANSYS, this paper analysis the dynamic response and setting of noise barrier in the way of discrete objects.Through the software ANSYS, build the finite element model of noise barrier for modal analysis, and according to the German online tests to calculate the time history curves of load,using APDL language to fluctuating the load loading to noise barrier, obtained response results, then discusses noise barrier setting. Finally, it further discusses selection of noise absorption materials, which will provides guiding suggestions for the noise-absorbing material selection. The main contents and important results of the above work are introduced:1 、 Comparison between modal analysis of 1-span and 8-span, found significant difference for the two frequencies, adjacent unit plate will influence each other, need to take the appropriate length to run in the dynamic analysis.2、Self-vibration frequency of model in above 10 Hz, does not in the frequency range of2 to 4 Hz of impulsive load, combined with load characteristics, so resonance does not occur when the structure under impulsive load.3、By the above modal analysis results, the damping matrix of the structure is calculated by using the theoretical knowledge of dynamics, the damping ratio and α,β are obtained,which provides the basis for dynamic analysis.4 、 Through the ANSYS in the APDL language, found the way that can loading the impulsive load into the noise barrier accurately.5、The establishment six models of 2-span, 4-span, 6-span, 8-span, 10-span and 12-span and the analysis of loading the impulsive load. The results show that it can put 16 m of the noise barrier model as the length of the analysis of dynamic response.6、Through changing the train speed, we can know that dynamic response of the end of the column increases as the train speed increases in a nonlinear relationship, polynomial fitting found that it is a secondary growth curve, and the fitting degree were more than 0.99.Towards the direction of high-speed train operation, the column of dynamic response showed increase at first and then decrease, and then increase again, until the end of the column reached maximum. In the penultimate columns and at the end of the column of dynamic response significant changes, we should pay attention to strengthening both the end columns and the adjacent columns in the design.7、Through changing the distance, we can know that dynamic response of the end of the column is power function relationship, with increase of the distance, column of dynamic response are smaller, and the fitting degree were 0.969.8、The models of different widths and thicknesses are established and analyzed. In a word, increase thickness or decrease width has good effects on the dynamic response.9、The models of different heights are established and analyzed. Improve the height of makes the dynamic response curve changes obviously, unfavorable to the stability of the structure. The dynamic stability of the structure can be improved by reducing the height of noise barrier.10、Based on the results of dynamic response, we can know that train running with400km/h, dynamic amplification coefficient of subgrade noise barrier is 1.59, bridge noise barrier of 12 m wide deck is 2.94, bridge noise barrier of 13 m wide deck is2.11.11 、Based on the above results, analyzed the settings of noise barrier and calculated fatigue strength of H-shaped steel column.12、Based on the results, we know that choose the noise barrier should be according to the distribution of noise spectrum, computing the frequency interval value, and determine the contribution distribution, then select suitable noise barrier.