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Since the 1840s, railways have been spreading all over Europe, America, Asia and other parts of the world, and have become the dominant transportation system moving large volume of goods and large number of passengers. As the demand grows, the train speed and carrying capacity have been increasing. The need to understand the complex stochastic nonlinear dynamics of high-speed trains to ensure the safety becomes urgent.
We adopt a popular 21-DOF high-speed vehicle model and consider two of the uncertain parameters and random excitations, which affect the dynamic responses of the vehicle.
1. Rail-wheel contact angle
Wheel-rail contact force depends greatly on the rail profile, materials and contact surface geometry of wheel and rail. The uncertain profile and contact surface of wheel and rail introduce randomness to the creep force. Statically determined creep force will lead to inaccurate response calculations. Here, we model the contact angle as a random variable.
2. Random wind load
We evaluate the random responses of the high-speed railway vehicle, and analyze the correlation between the response variables. The correlation of the response provides us the cause-effect relations among different parts of the vehicle, and suggests ways to modify the component in order to achieve better dynamic response that induces less damage to the vehicle.