高速铁路用WJ-8型扣件弹条模态特征试验研究

高速铁路无砟轨道在钢轨波浪形磨耗或车轮多边形磨耗等影响下扣件产生共振导致弹条断裂的情况时有发生。WJ-8型扣件是我国高速铁路无砟轨道结构常用扣件,为了分析其弹条断裂损伤机理,采用锤击激励法对扣件弹条的模态特征进行了试验研究。结果表明:标准安装状态下WJ-8型扣件配套使用的W1型弹条在0～1 000 Hz频率范围内具有2阶模态,第1阶模态振型为弹条两侧肢以扣压端和支承端为支点反对称外翻振动,两侧肢的振动方向相反,第2阶模态振型为弹条两侧肢以扣压端和支承端为支点对称外翻振动,两侧肢的振动方向相同;弹条固有频率波动与安装状态有关,可通过调整弹条安装状态,避免弹条在轮轨的高频激励下产生共振,从而减轻弹条伤损。

Experimental Study on Modal Characteristics of WJ-8 Fastener Elastic Bars for High Speed Railway

Under the inf luence of rail corrugation or wheel polygon wear,the resonance of fasteners on ballastless track of high speed railway often leads to the fracture of elastic bars.W J -8 fasteners are commonly used in ballastless track structure of high speed railway in China.In order to analyze the fracture damage mechanism of the elastic bar,the modal characteristics of the fastener elastic bar were studied by hammering excitation method.The results show that in the standard installation state,the W1 type elastic bars matched with W J -8 fasteners have second-order modes in the frequency range of 0~ 1 000 Hz .The f irst mode is anti-symmetrical valgus vibration of both elastic bar limbs with buckle end and support end as fulcrum and the vibration direction of both limbs is opposite,the second mode is symmetrical valgus vibration of the both elastic bar limbs with the buckle end and the support end as the fulcrum and the vibration direction of both limbs is the same.The natural frequency f luctuation of the elastic bar is related to the installation state,the resonance of the elastic bar under the high frequency excitation of wheel and rail can be avoided by adjusting the installation state of the elastic bar,thus the damage of the elastic bar can be reduced.