中国自主品牌征战金砖国家策略研究（续）

随着中国汽车市场日趋饱和，自主品牌汽车企业“走出去”的愿望日益强烈，金砖国家开始受到中国自主品牌汽车企业的广泛关注。金砖国家经济增长迅速，汽车工业发展却普遍相对较晚，市场潜力巨大。文章通过定性与定量相结合的方法进行统计分析，对比研究各国经济状况、开放程度、市场潜力、燃料价格等汽车产业发展主要相关影响因素，并结合各金砖国家汽车市场发展现状和特征，分别提出中国汽车自主品牌进入不同国家的发展方向和发展策略。     

自重荷载作用下悬索静力解析解

从悬索微元体平衡出发,分别推导以悬索张力分量、索长等为参变量,考虑和不考虑悬索自重集度变化的两种悬索解析式。通过比较发现,去掉悬索伸长影响项,就可直接由考虑悬索自重集度变化的解析式缩减到不考虑其变化的解析式。在用索长表达的解析式中,考虑悬索自重集度变化时对应无应力索长,不考虑悬索自重集度变化时对应有应力索长。算例假定斜拉索梁端张力的竖向分量为已知,按以上两种情况,分别建立以悬索张力的水平分量和塔端张力的竖向分量为未知数的非线性方程组,用拟牛顿法求解,得到悬索未知参数的精确解析解。     

在悬索桥中再度研究设计应用板式加劲梁

根据悬索桥的基础理论及其加劲梁基本结构形式的发展演变和设计流派的研究,结合美国塔科玛桥板式加劲梁悬索桥的风毁工程实例,着重对板式加劲梁结构的抗风稳定性和工程措施再度研究分析。在此基础上,结合实桥设计将研究成果分别应用于预应力板式加劲梁悬索桥和钢板式加劲梁悬索     

State observer-based sliding mode control for semi-active hydro-pneumatic suspension

This paper proposes an improved virtual reference model for semi-active suspension to coordinate the vehicle ride comfort and handling stability. The reference model combines the virtues of sky-hook with ground-hook control logic, and the hybrid coefficient is tuned according to the longitudinal and lateral acceleration so as to improve the vehicle stability especially in high-speed condition. Suspension state observer based on unscented Kalman filter is designed. A sliding mode controller (SMC) is developed to track the states of the reference model. The stability of the SMC strategy is proven by means of Lyapunov function taking into account the nonlinear damper characteristics and sprung mass variation of the vehicle. Finally, the performance of the controller is demonstrated under three typical working conditions: the random road excitation, speed bump road and sharp acceleration and braking. The simulation results indicated that, compared with the traditional passive suspension, the proposed control algorithm can offer a better coordination between vehicle ride comfort and handling stability. This approach provides a viable alternative to costlier active suspension control systems for commercial vehicles.     

New nonlinear bushing model for general excitations using Bouc-Wen hysteretic model

Because the characteristics of rubber bushing significantly affect the accuracy of vehicle dynamics simulations, they should be accurately modeled in the vehicle suspension model. In this paper, a new nonlinear bushing model for automotive bushing components is developed to improve the accuracy of vehicle dynamics analysis. Bushing components were first tested to capture the nonlinear and hysteretic behavior of typical elements by using a MTS 3-axis elastomer tester. A simple Bouc-Wen hysteretic differential model was modified to generate a more precise rubber bushing model. A sine wave, step input, and random excitations are imposed on the bushing. The ADAMS program is used to calculate sensitivity and the VisualDOC program is employed to find the optimal parameters for the bushing model. An error function is designed to find optimal parameters of the model. Parameter identification is carried out to satisfy the static and dynamic characteristics due to sine and step excitation inputs. It was proved that the proposed model could predict the bushing forces under sine, step, and random inputs well. The errors are within 10% in the overall range. To show the validity of the proposed model, a numerical example was also carried out. Because the bushing forces due to random excitation input show good agreement with experiments, the proposed bushing model is available in the vehicle dynamics simulation.     

悬索桥造型设计的美学分析

桥梁造型的美学设计是桥梁美学的基础,本文主要对悬索桥的线形、桥塔、主缆与吊索、加劲梁、锚碇等结构设计进行美学分析。     

某轮式起重机后悬架板簧销的强度校核

本文对某轮式起重机后悬架的推力杆以及板簧销的受力进行了详尽的分析以及计算,为轮式起重机后悬架系统各总成的设计提供理论依据。     

基于Modelica的电动汽车悬架系统建模与仿真分析

基于多领域统一建模的标准语言Modelica建立了电动汽车悬架系统模型库,并以一款电动客车的悬架系统为研究对象,对其操纵稳定性和行驶平顺性进行仿真分析,验证了悬架系统建模的准确性。采用正交试验方法对行驶平顺性进行了优化。仿真和优化结果表明,所设计悬架能够满足电动汽车的性能需求。     

青草背长江大桥主缆缠丝初拉力的修正分析

文章阐述了悬索桥主缆缠丝拉力的变化过程和主缆缠丝预加力的计算方法,并结合重庆涪陵青草背长江大桥主桥工程实例,在原设计缠丝初始导入力的基础上通过分析计算与比较,对该桥主缆缠丝的原设计初拉力进行了修正,为类似工程项目提供参考。