Vehicle Bridge Interaction Modeling-Quarter Car-1D Bridge

This code provides a finite element modeling for the Vehicle Bridge Interaction Problem. The vehicle is modeled as a quarter car with two degrees of freedom accounting for the body mass bouncing and the axle mass bouncing. While the Bridge is modeled using Finite Element Euler Bernoulli Beams. The program can be used to simulate the VBI with and without road roughness. Also a damage model is added to simulate the effect of structural damages using Sinha Damage model (2002). The code is built upon the contact force concept. In this concept the vehicle equation of motion and the bridge equation of motion are solved separately by equating the contact force between the vehicle and the bridge. The equations of motion are solved explicitly using Newmark-Beta Integration scheme. For a very small time step size (dt

本代码针对车桥耦合振动问题（Vehicle Bridge Interaction Problem）提供了有限元建模方案。将车辆建模为包含两自由度的四分之一车辆模型，该模型可表征车身垂向跳动与车轴垂向振动；桥梁则采用有限元欧拉-伯努利梁（Euler Bernoulli Beams）进行建模。本程序可模拟存在与不存在路面不平整度的车桥耦合场景，同时集成了基于2002年Sinha损伤模型（Sinha Damage model）的结构损伤效应模拟模块。本代码基于接触力理论构建：通过联立车辆与桥梁间的接触力，分别求解车辆运动方程与桥梁运动方程，运动方程采用纽马克-β积分法（Newmark-Beta Integration scheme）进行显式求解，适配极小时间步长（dt