摘要
该文用模态叠加法对城市轨道交通槽型梁进行车-轨-桥耦合动力计算,借助SYSNOISE求出模态声传递向量MATVs,进而用MATVs和梁的模态坐标响应计算桥梁的结构噪声。噪声计算值与实测值在频率分布和幅值上有较高的一致性,证明振动与噪声数值模型的可靠性。槽型梁结构噪声的线性声压级峰值频率为40Hz^80Hz,数值计算表明:动力分析只需考虑轮轨竖向接触即可满足结构噪声计算要求;考虑200Hz以下的声源激励和100Hz以下的结构模态作为边界条件可达到较好的噪声计算精度;调节轨下胶垫的刚度能有效减小结构振动,降低结构噪声2dB^3dB;声压级和车速有强线性关系。
The mode superposition method is applied to compute the dynamic responses of a trough girder under urban rail transit trains based on vehicle-track-bridge interaction theory. The modal acoustic transfer vectors （MATVs） are obtained by using the SYSNOISE software. The structure-borne noise is then computed with the MATVs and the mode coordinates of the girder. The agreement between the calculated results and the measured ones in both frequency and amplitude demonstrates the reliability of the computational method. The peak frequencies of the structure-borne noise are found to be between 40Hz and 80Hz. The numerical results show that the excitations below 200Hz and the bridge modes below 100Hz can be used to compute the structure-borne noise with much high degree of accuracy. Only vertical contact forces between wheels and rails are required to simulate the noise numerically. The vibrations of the girder can be reduced effectively and the structure-bome noise can be reduced by 2dB-3dB through adjusting the stiffness of rubber pads under the rails. It is found that the sound pressure levels are obviously linear with the train speeds.
出处
《工程力学》
EI
CSCD
北大核心
2013年第2期190-195,202,共7页
Engineering Mechanics
关键词
轨道交通
槽型梁
结构噪声
模态叠加法
模态声传递向量
线性声压级
urban rail transit
trough girders
structure-borne noise
mode superposition method
modal acoustictransfer vector
linear sound pressure levels
