高速列车车体轻量化层状复合结构隔声设计

随着高速列车车体结构轻量化的发展,层状复合结构车体在高速列车上得到广泛应用,提高层状复合结构的隔声性能,是高速列车减振降噪的关键技术。基于传递矩阵法,建立"铝板+多孔材料层+空气层+碳纤维增强板"的典型高速列车层状复合结构车体隔声计算分析模型,并分析多孔材料和空气层对层状复合结构车体隔声性能的影响。结果显示,混响声场激励下,在铝板和碳纤维增强版之间仅增加空气层只能提高车体结构高频隔声量,低频部分会由于"板-空气-板"的系统耦合共振,形成显著吻合谷,导致其隔声性能在吻合谷频率处大幅下降。对此,利用多孔材料吸声原理,提出在空气层中增加吸声材料层,抑制隔声吻合低谷,通过优化设计,得出"铝板+空气层+吸声材料+空气层+碳纤维增强板"的优化结构形式,在实现车体轻量化目标同时,可有效提高其隔声性能。

Study on Sound Insulation and Lightening Design of Layered Composite Structures for High-speed Trains

Abstract: The composite structure is widely used for the weight reduction in high-speed train. Improving the sound insulation properties of composite structure is the key technology of vibration and noise reduction for high-speed train. Based on the transfer matrix method, a typical composite structure of high-speed train was established, the sound insulation property of the composite structure with air layers and porous materials are analyzed by numerical calculations. The results show that adding an air layer between aluminum panel and carbon fiber reinforced polymer panel cannot improve the sound insulation property of the composite structure in the lower frequency band under a diffuse field excitation. Instead the transmission loss curves have acoustic valleys in some specific frequencies because of the cavity resonance. But adding a porous material layer in the air layer can suppress the acoustic valleys according to the principle of sound absorption of porous materials. Through the optimization design, the optimized structure form like “aluminum panel + air layer +porous material layer + air layer + CFRP panel” was obtained. It can improve the sound insulation effectively as well as reduce the weight of structure.