为了在初始设计阶段预测车辆平顺性、优化设计方案，建立考虑车架柔性的6 ×4商用车半车振动模型，进行随机输入行驶模拟试验，分析了车架弯曲、驾驶室悬置、发动机悬置及座椅悬置对整车平顺性的影响． 利用假设模态方法建立车架弯曲模型，分析了车架柔性对整车平顺性的影响． 通过灵敏度分析评价车辆主要参数对平顺性的影响，最后用模拟退火粒子群优化算法进行悬架和驾驶室悬置参数的优化匹配． 仿真结果表明，前轴的悬架刚度和车架的第一阶弯曲振动对整车平顺性的影响很大，驾驶室悬置和座椅悬置对平顺性的贡献量最大．

In order to predict the ride comfort and optimize the design scheme during the initial design stage，a
half car vibration model of 6 ×4 commercial vehicles is constructed by taking into account the frame flexibility，and random input running tests are simulated． Next，the influences of vehicle suspension，cab suspension，engine mount and seat suspension on the ride comfort are analyzed． Then，a frame bending model is constructed by means of the assumed mode method，and the influence of the frame flexibility on the ride comfort of a whole vehicle is revealed． Furthermore，the influence of main vehicle parameters on the ride comfort is also evaluated through sensitivity analysis． Finally，the optimal matching of primary suspension and secondary one is processed by using the particle swarm optimization (PSO) algorithm． Simulation results show that both the stiffness of the first axle suspension and the first bending vibration of frame greatly affect the ride comfort，and the cab suspension and the seat suspension contribute most to the ride comfort．