非线性商用车仿生悬架等偏频等高度设计

针对商用车悬架基于满载设计存在的变簧载时车辆平顺性差的问题，提出了一种基于双菱形仿袋鼠腿悬架(简称“仿生悬架”)的等偏频等高度设计方案，并对该方案进行研究、分析与评价，以改善商用车的平顺性。通过静力学特性分析，得到了仿生悬架的弹性特性和刚度特性并开展了等偏频等高度设计研究。研究发现：仿生悬架具有较理想的非线性弹性特性和刚度特性，相比线性悬架，具有更多的动容量和更强的抗击穿能力；悬架的初始角度和刚度比对其特性和行程区间有重要影响；通过调节仿生悬架初始角度可实现不同簧载质量悬架的等偏频等高度设计，表明所提设计方案可行。仿真分析结果表明，在不同路面等级(B、C、D)、不同车速(40～100 km/h)下，商用车经仿生悬架等偏频等高度设计后，车身加速度均方根值较设计前明显减小，平顺性得到有效改善。搭建了仿生悬架实验测试模型，在不同路面条件下，等偏频等高度设计后，空载和半载垂向加速度均方根值较设计前分别减小20.6%～28.3%和12.1%～20.4%,验证了等偏频等高度设计方案的正确性和有效性。

Constant Partial Frequency and Constant Height Design of Nonlinear Commercial Vehicle Bionic Suspensions

Aiming at the problems of poor vehicle ride comfort during variable sprung mass of commercial vehicle suspensions based on full-load design, a design scheme of constant partial frequency and constant height was proposed based on double diamond-shaped kangaroo leg suspensions(bionic suspension). The scheme was researched, analyzed and evaluated to improve the ride comfort of commercial vehicles. Through the analysis of statics characteristics, the elastic characteristics and stiffness characteristics of the bionic suspensions were obtained, and the constant partial frequency and constant height design was carried out. It is found that the bionic suspension has ideal nonlinear elastic characteristics and stiffness characteristics. Compared with the linear suspensions, it has more dynamic capacity and strong anti-breakthrough ability. The initial angle and stiffness ratio of the suspensions have important impacts on the characteristics and stroke range. By adjusting the initial angle of the bionic suspensions, the constant partial frequency and constant height design maybe realized for different sprung mass, which shows the proposed scheme is feasible. The simulation analysis results show that under different road grades(B, C, D) and different vehicle speeds(40~100 km/h), the body acceleration root mean square value is significantly reduced compared with before design, and the ride comfort is effectively improved after the constant partial frequency and constant height design for the commercial vehicle bionic suspensions. After the design of constant partial frequency and constant height, under different road conditions, the no-load and half-load vertical acceleration root mean square values of the bionic suspension experimental test model are decreased by 20.6%~28.3% and 12.1%~20.4% respectively compare with before design, which verified the correctness and effectiveness of the design schemes of constant height and constant partial frequency.