摘要
为探究应力波界面透反射行为对分层黏弹性颗粒材料细观动力响应的影响规律,推导了界面透反射系数的理论表达,并建立了单频应力波入射和多频应力波入射两类条件下分层黏弹性颗粒材料的细观动力响应模型.典型算例分析结果表明:单频应力波入射时,上层颗粒动力响应形成“驻波”现象;双频应力波入射时,上下层颗粒动力响应均形成“行波”现象;两类条件下,分层界面处相邻颗粒的位移振幅均出现明显突变.以高速铁路无砟轨道路基基床为应用场景,分析基床填料刚度、阻尼系数及密度等参数对界面透反射特性的影响规律,探讨分层颗粒材料动力变形的调控思路,即增加基床表层填料的刚度、阻尼系数及密度,或减小基床底层填料的密度等措施可实现增益透射、抑制反射目标.此外,动力变形调控时还需控制路基颗粒材料固有频率远离动载激振特征频率.
In order to investigate the influence of stress wave transmission and reflection behaviors on mesoscopic vibration response of layered viscoelastic granular materials,the theoretical expressions of the transmission and reflection coefficients were derived.Then the mesoscopic vibration response models of layered viscoelastic granular materials under single-frequency and multi-frequency stress wave incidence were established.The results of typical examples show that standing waves appear in the upper layer when the single-frequency stress wave is incident,and traveling waves appear in the upper and lower layers when the dual-frequency stress wave is incident.In both cases,the amplitudes of the adjacent particles change sharply at the layered interface.Based on the ballastless track-subgrade bed for high-speed railway,the effects of parameters such as stiffness,damping coefficient and density of subgrade bed on the transmission and reflection characteristics at layered interface were analyzed.The idea of regulating the dynamic deformation of layered granular materials was discussed.It is found that increasing the stiffness,damping coefficient and density of surface layer materials and reducing the density of bottom layer materials can increase the beneficial transmission and restrain the reflection.In addition,it is necessary to control the natural frequency of granular materials to keep it far away from the characteristic frequency of dynamic vibration.
作者
肖军华
白英琦
张骁
刘志勇
王炳龙
XIAO Junhua;BAI Yingqi;ZHANG Xiao;LIU Zhiyong;WANG Binglong(Key Laboratory of Road and Traffic Engineering of Ministry of Education,Tongji University,Shanghai 201804,China;Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety,Tongi University,Shanghai 201804,China;China Development Bank Shaanxi Branch,Xi'an 200120,Shaanxi,China)
出处
《力学季刊》
CAS
CSCD
北大核心
2023年第3期620-632,共13页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(U2034204)。
关键词
黏弹性颗粒材料
应力波
透反射
动力响应
viscoelastic granular materials
stress wave
transmission and reflection
dynamic response
