多特征频率下槽形梁面板综合声学贡献量分析

Application of integrated panel acoustics contribution theory in the study of simply-supported trough girder under multi-characteristic frequency

为探讨城市轨道交通槽形梁低频噪声综合面板声学贡献量,以某拟建30 m轨道交通槽形梁为研究对象,开展结构声辐射特性研究。基于有限元/边界元法分别建立槽形梁有限元模型、声学边界元模型,采用间接边界元法分析槽形梁的声辐射特性。在此基础上,应用声传递向量法对槽形梁的结构噪声进行面板声学分析,引入特征频率计权系数以及场点权重系数确定多特征频率下对综合声场声学贡献量最大的关键槽形梁面板。研究结果表明:轨道交通槽形梁的结构噪声以20~80 Hz的低频为主,各场点在31.5 Hz和63 Hz处出现噪声峰值;槽形梁综合声场声压主要由底板贡献,翼缘板对综合声场声压贡献较小,腹板对综合远声场有负影响;应当有针对性地对关键面板进行结构优化改善结构噪声性能。

in order to study the integrated panel acoustics contribution of simply-supported trough girder in urban rail transit. Taking a 30m concrete trough girder as the research object , currying out the characteristic research on the acoustic radiation of the structural system Structural acoustic radiation characteristics.Finite element method and boundary element method are used to establish the finite element model and the acoustic boundary element model, and the acoustic radiation characteristics of the Trough Girder are analyzed by the method of the indirect boundary element method. On the basis of the above, the acoustic analysis of the structural noise of the trough girder is performed by using the acoustic transfer vector method.Introduced the weight coefficient of characteristic frequency and field point to determine the frequency character of integrated acoustic contribution amount the biggest key trough girder panel under multi-characteristic frequency.The results of the study show that： the structure noise of trough girder dominated by 20~80Hz low frequency and the field point at 31.5 Hz and 63Hz appeared peak noise; the sound pressure of trough girder is mainly contributed by the bottom plate, flange plate to integrated sound pressure with smaller, web of far field have negative effects on integrated far filed sound pressure; Structural optimization of the key panel should be carried out to improve the performance of the structure noise.