Research on the dynamic characteristics of the dynamic track stabilizer side searing
The dynamic characteristics of side bearing are one of the key factors for further study on the overall behaviour of the dynamic track stabilizer. The constitutive parameters of rubber spring were determined by the static experiment. Based on the parameters, the finite element model of side bearing was built and the reliability of side bearing model was verified by experiment. The vertical dynamic characteristics of side bearing were studied on the base of LS-DYNA. According to the analytical results, the dynamic characteristics of the side bearing spring constants and its internal damping are nonlinear under different compound of loads and frequencies. The conclusion can provide a theoretical basis to the optimal design of the side searing.
Non-Linear Behavior of a Rubber Isolator System Using Fractional Derivatives
A non-linear rubber isolator included in a dynamic system is examined where influences of dynamic amplitude and frequency are investigated through measurements and modeling. The frequency dependence of the isolator is modeled by a fractional calculus element while a frictional component accounts for its amplitude dependence. The model works in the time-domain and simulations of harmonic and non-harmonic motion are compared to measurements. Good agreement is obtained in a wide frequency and amplitude range for a freely oscillating one degree of freedom system, with the isolator acting as a coupling between exciting foundation and mass, and for a single isolator showing the typical amplitude dependence known as the Payne effect. The model is found to be superior to the commonly applied Kelvin–Voigt element in modeling the dynamic isolator properties.
Philip Roth’s Great Books: A Reading of The Human Stain
Philip Roth belongs to the first generation of American novelists for whom a university education in the liberal arts was the norm. This essay charts Roth’s developing acquaintance with classical literature, the starting point for Great Books courses in the 1950s, and the implications for his fiction of his understanding of the difference in scope and purpose between the two representative classical genres. It focuses on The Human Stain (2000), the novel in which he reflects most directly upon what tragedy and epic once did, and what might happen to novels if they became more like the one or the other.