基于界面接触算法的车桥耦合动力学分析

发布时间：2018-11-04 13:15

【摘要】：考虑轨道不平顺及其可能引起的跳车现象,采用接触算法中的罚刚度法,在接触力与接触面之间建立了力与位移之间的线性关系。通过合理调整罚刚度值,有效控制穿透距离,将计算中迭代次数控制在合理范围之内,避免了病态刚度矩阵,使得计算结果趋近于真实值。利用精细积分技术,在时间域内进行参数离散化处理,构造时间差分格式,利用直接积分法和对应的初始条件,得到结构位移、速度和加速度关于时间递推的表达式。为提高计算效率,并保证计算结果的收敛性,将整体分析过程划分为2个子模型(移动力模型,刚性梁模型)。在给定收敛性准则的基础上,采用循环迭代技术进行数值求解;借助于MATLAB平台完成了上述车桥耦合动力学分析的编程。数值分析结果表明:当轨道平顺时,所提算法结果与Hertz弹簧模型结果高度一致;同时考虑单跨和三跨刚构桥,存在加减速度情况时,所提算法结果与Hertz弹簧模型结果完全一致,证明了所提算法的可靠性;考虑轨道不平顺时,所提算法结果与Hertz弹簧模型结果具有相同的变化规律,但数值偏高,反映了跳车冲击力的动力效应;对于行驶在桥梁上的多车情况,特别是轨道不平顺情况下,车辆跳起和下落冲击是客观存在的,采用所提的界面接触法能够真实地模拟车桥动力学耦合工况。
[Abstract]:Considering the track irregularity and the possible jump phenomenon, a linear relationship between the contact force and the contact surface is established by using the penalty stiffness method in the contact algorithm. By reasonably adjusting the penalty stiffness value and effectively controlling the penetration distance, the iteration number in the calculation is controlled within a reasonable range, and the ill-conditioned stiffness matrix is avoided, which makes the calculation result approach to the real value. By using the precise integration technique, the parameters are discretized in time domain, the time difference scheme is constructed, and the expressions of displacement, velocity and acceleration about time recursion are obtained by using direct integration method and corresponding initial conditions. In order to improve the computational efficiency and ensure the convergence of the calculation results, the whole analysis process is divided into two sub-models (moving dynamic model, rigid beam model). On the basis of the given convergence criterion, the cyclic iteration technique is used to solve the numerical solution, and the programming of the above vehicle-bridge coupling dynamics analysis is completed with the help of MATLAB platform. The numerical results show that the proposed algorithm is in good agreement with the Hertz spring model when the track is smooth. At the same time, considering the single-span and three-span rigid frame bridges, the proposed algorithm is in good agreement with the results of Hertz spring model, which proves the reliability of the proposed algorithm. When considering track irregularity, the proposed algorithm has the same variation law as the Hertz spring model, but the numerical value is on the high side, which reflects the dynamic effect of the impact force. In the case of multiple vehicles travelling on bridges, especially in the case of track irregularity, the jumping and falling impact of vehicles exist objectively. The proposed interface contact method can be used to simulate the vehicle-bridge dynamic coupling conditions.
【作者单位】：华中科技大学土木工程与力学学院;
【基金】：国家自然科学基金项目(51678264)
【分类号】：U441.3

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