A frequency and amplitude dependent model of rail pads for the dynamic analysis of train-track interaction

• Published in: Science China. Technological sciences Vol. 58; no. 2; pp. 191 - 201
• Main Authors: Zhu, ShengYang, Cai, ChengBiao, Luo, Zhen, Liao, ZhongQi
• Format: Journal Article
• Language: English
• Published: Heidelberg Science China Press 01.02.2015
• Subjects: Amplitudes; Dynamic tests; Dynamical systems; Dynamics; Engineering; Excitation; Mathematical models; Nonlinear dynamics; Rails; 列车; 多体系统; 幅度; 激励频率; 相关模型; 轨道相互作用; 钢轨接头; 非线性方程组; vehicle-track coupled dynamics; frequency dependent; rail pads; amplitude dependent
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-014-5686-y

A frequency and amplitude dependent model is used to describe the complex behavior of rail pads. It is implemented into the dynamic analysis of three dimensional coupled vehicle-slab track （3D-CVST） systems. The vehicle is treated as a 35-degree- of-freedom multi-body system, and the slab track is represented by two continuous Bernoulli-Euler beams supported by a se- ries of elastic rectangle plates on a viscoelastic foundation. The rail pad model takes into account the influences of the excita- tion frequency and of the displacement amplitude through a fractional derivative element, and a nonlinear friction element, re- spectively. The Granwald representation of the fractional derivatives is employed to numerically solve the fractional and non- linear equations of motion of the 3D-CVST system by means of an explicit integration algorithm. A dynamic analysis of the 3D-CVST system exposed to excitations of rail harmonic irregularities is primarily carried out, which reveals the dependence of stiffness and damping on excitation frequency and displacement amplitude. Subsequently, sensitive analyses of the model parameters are investigated by conducting the dynamic analysis of the 3D-CVST system subjected to excitations of welded rail joint irregularities. Following this, parameters of the rail pad model are optimized with respect to experimental values. For elu- cidation, the 3D-CVST dynamic model incorporated with the rail pads model is used to calculate the wheel/rail forces induced by excitations of measured random track irregularities. Further, the numerical results are compared with experimental data, demonstrating the reliability of the proposed model.