无横撑下承式系杆拱侧倾稳定实用计算方法

以无横撑下承式系杆拱桥侧倾稳定问题为背景,用能量变分方法导出了其侧倾稳定的近似解析解,并通过具体算例,比较了由于吊杆的非保向力作用对其侧倾稳定性的影响,并将本文方法与工程设计中常用方法作了比较.     

汽车最大侧倾稳定角的简化计算

汽车最大侧倾稳定角直观地反映了汽车的侧倾稳定性能,是影响汽车行车安全的一个重要指标。本文对国内外在汽车静态侧倾稳定性方面的研究现状进行了概括和总结,归纳了当前在汽车最大侧倾稳定角测量及计算方面存在的主要问题,并在此基础上建立了考虑悬架及轮胎变形的汽车静态侧倾简化模型,通过理论推导得出通过汽车质心高度计算汽车最大侧倾稳定角的公式,提出了一种考虑汽车悬架及轮胎变形时通过汽车质心高度换算最大侧倾稳定角的测量计算方法。     

中承式拱桥的侧倾稳定性研究

系杆拱桥的拱肋上作用有保向力和非保向力两种类型的荷载,采用能量法推导出中承式系杆拱桥侧倾稳定临界荷载的一般公式,并通过算例与有限元计算的结果进行了比较验证,获得的系杆拱桥侧倾稳定临界荷载的概念与裸拱侧倾稳定临界荷载是一致的。     

侧倾转向和侧倾外倾系数的计算与分析

论述了侧倾转向和侧倾外倾系数的意义和获得方法,然后以某汽车为例计算了侧倾转向系数和侧倾外倾系数,并对其进行了分析.探索了一种计算不同侧向加速度下侧倾转向和侧倾外倾系数的方法.     

三轴罐式半挂车侧倾稳定性评估方法

依据GB 28373-2012《N类和O类罐式车辆侧倾稳定性》标准中的要求与模拟计算方法,以典型三轴罐式半挂车为研究对象,对其侧倾稳定角计算过程进行了研究,确定基准研究参数。采用控制变量法,对选定的多组参数值进行计算,分析所得数据,剔除对侧倾稳定角影响较小的因素,找出结果数据的规律,从而将计算方法简化,得到了简便评估三轴罐式半挂车是否符合侧倾稳定性要求的计算公式,为该类车型的侧倾稳定性设计提供一定的参考。     

无横撑下承式系杆拱桥侧倾稳定临界荷载的一般公式

通过对系杆拱桥作用在拱肋上的荷载性质进行了分析,采用能量法推导出无横撑下承式系杆拱桥侧倾稳定临界荷载的一般公式。指出系杆拱桥侧倾稳定存在有2种临界荷载,即自重荷载直接作用的临界荷载和吊杆拉力等效薄膜力的临界荷载,并通过算例对自重荷载直接作用的临界荷载所提出的方法和有限元法进行了比较验证。     

液压互联悬架抗侧倾控制研究（双语出版）

针对车辆减少能量消耗与提高抗侧倾能力需求,提出了一种主/被动可切换的液压互联悬架抗侧倾控制方法。基于9自由度车辆动力学模型,考虑蓄能器、液压缸、液压泵三者之间耦合的体积-流量-压力特性,建立液压互联悬架主动控制时域模型;结合"车身侧倾角-车身侧倾角速度"相平面法及车辆侧向加速度,得到车辆侧倾稳定域,并提出液压互联悬架系统侧倾稳定性控制介入与退出判据;在此基础上,采用Backstepping非线性控制算法设计主动液压互联抗侧倾控制器。最后,分析并改进侧倾稳定性评价指标,通过在MATLAB/Simulink环境下进行高速双移线、鱼钩试验等极端工况数值仿真,验证所提出的液压互联悬架主/被动切换控制系统能在减少能量消耗的情况下能否提高车辆抗侧翻的能力。研究结果表明：所提出的控制系统能有效提高车辆抗侧翻能力;当车辆侧倾状态超出设定的侧倾稳定区域介入线时,液压互联悬架系统由被动模式切换为主动抗侧倾模式,控制车辆侧倾状态回到稳定区域,以提高车辆侧倾稳定性;当判定车辆侧倾状态满足主动控制退出条件时,液压互联悬架系统回到被动模式,以减小能量消耗。     

液压互联悬架抗侧倾控制研究

针对车辆减少能量消耗与提高抗侧倾能力需求,提出了一种主/被动可切换的液压互联悬架抗侧倾控制方法。基于9自由度车辆动力学模型,考虑蓄能器、液压缸、液压泵三者之间耦合的体积-流量-压力特性,建立液压互联悬架主动控制时域模型;结合"车身侧倾角-车身侧倾角速度"相平面法及车辆侧向加速度,得到车辆侧倾稳定域,并提出液压互联悬架系统侧倾稳定性控制介入与退出判据;在此基础上,采用Backstepping非线性控制算法设计主动液压互联抗侧倾控制器。最后,分析并改进侧倾稳定性评价指标,通过在MATLAB/Simulink环境下进行高速双移线、鱼钩试验等极端工况数值仿真,验证所提出的液压互联悬架主/被动切换控制系统能在减少能量消耗的情况下能否提高车辆抗侧翻的能力。研究结果表明:所提出的控制系统能有效提高车辆抗侧翻能力;当车辆侧倾状态超出设定的侧倾稳定区域介入线时,液压互联悬架系统由被动模式切换为主动抗侧倾模式,控制车辆侧倾状态回到稳定区域,以提高车辆侧倾稳定性;当判定车辆侧倾状态满足主动控制退出条件时,液压互联悬架系统回到被动模式,以减小能量消耗。     

汽车静态侧翻稳定角的计算方法

本文推导了一种计算汽车静态侧翻稳定角的方法，该方法考虑了悬架的侧倾和前后轮距的不同，从而具有较高的准确性和实际意义。给出了某车型的计算实例，并与不计悬架侧倾时的计算结果进行了对比。     

索—塔—梁耦合作用下的斜拉桥侧倾稳定研究

本文用能量变分方法导索、塔与梁耦合作用下的单索面斜拉桥倾稳定的计算公式，建立了一索、桥塔和主梁所组成的斜拉桥系统的稳定分析实用计算方法。并通过分析比较，从理论上论述了斜拉桥单个杆件稳定与整个系统稳定的关系，揭示了将斜拉桥作为一个系统进行侧倾稳定分析的必要性和重要性。     

汽车列车横向稳定性研究

汽车列车是牵引汽车与挂车相互作用、相互耦合的复杂系统,其横向稳定性研究涉及多体动力学、刚柔耦合力学、气体动力学、车辆非线性运动和电子控制等多个学科.本文论述了汽车列车横向稳定性的国内外研究现状、研究方法和试验手段,探讨了使用参数和结构参数对汽车列车横向稳定性的影响,分析了角阶跃输入下汽车列车侧向加速度响应.最后,对汽车列车动力学数字仿真算法及代表性软件进行了分析阐述.     

ABS性能评价方法的研究

在分析原有ＡＢＳ评价方法的基础上,针对附着系数利用率这个评价指标存在的不足,比较完全地考虑了制动过程中侧向与纵向的附着情况,提出了一种侧重于侧向稳定性的评价方法。对于评价的指标,便于用仿真计算验证其正确性,从而达到在设计阶段就可对ＡＢＳ性能进行分析评价,缩短了ＡＢＳ的开发周期。     

A comprehensive study on the stability analysis of vehicle dynamics with pure/combined-slip tyre models

In this paper, a vehicle's lateral dynamic model is developed based on the pure and the combined-slip LuGre tyre models. Conventional vehicle's lateral dynamic methods derive handling models utilising linear tyres and pure-slip assumptions. The current article proposes a general lateral dynamic model, which takes the linear and nonlinear behaviours of the tyre into account using the pure and combined-slip assumptions separately. The developed methodology also incorporates various normal loads at each corner and provides a proper tyre–vehicle platform for control and estimation applications. Steady-state and transient LuGre models are also used in the model development and their responses are compared in different driving scenarios. Considering the fact that the vehicle dynamics is time-varying, the stability of the suggested time-varying model is investigated using an affine quadratic stability approach, and a novel approach to define the critical longitudinal speed is suggested and compared with that of conventional lateral stability methods. Simulations have been conducted and the results are used to validate the proposed method.     

基于NMPC的智能汽车纵横向综合轨迹跟踪控制

本文中针对大曲率转弯工况下,智能汽车纵横向动力学特性的耦合和动力学约束导致轨迹跟踪精度和稳定性下降的问题,提出一种基于非线性模型预测控制(NMPC)的纵横向综合轨迹跟踪控制方法,通过NMPC和障碍函数法(BM)的有效结合,提高了跟踪精度,改善了行驶稳定性。首先建立四轮驱动-前轮转向智能汽车动力学模型和轨迹跟踪模型,采用非线性模型预测控制计算出期望的纵向力、侧向力和横摆力矩;然后基于轮胎动力学模型建立带约束的非线性规划数学模型,利用障碍函数法求解出四轮轮胎力的最优分配,并最终实现四轮驱动智能汽车纵横向综合轨迹跟踪控制。最后进行Carsim和Simulink联合仿真,结果表明,与传统的预瞄PID控制相比,所提方法可在考虑纵横向动力学耦合的情况下明显改善跟踪精度和行驶稳定性。     

钢管混凝土拱桥矢跨比对稳定性影响的研究

钢管混凝土拱桥可以通过改变矢跨比来改善其整体稳定性。利用有限元方法研究钢管混凝土拱桥的矢跨比对稳定性的影响,给出矢跨比的合理取值范围。结果表明,在考虑几何非线性影响的情况下,钢管混凝土拱桥的矢跨比宜选在1/3.5~1/5。     

大跨度中承式拱桥侧向稳定的空间有限元分析

以浙江淳安跨度为198m的中承式钢管混凝土劲性骨架拱桥为工程背景，采用通用的有限元软件ANSYS，分析了拱肋刚度及横向联系刚度、设置的位置、形式等因素对大跨度中承式拱桥侧向稳定的影响，为此类桥梁的设计和施工提供参考。     

Effect of vertical and lateral coupling between tyre and road on vehicle rollover

The vehicle stability involves many aspects, such as the anti-rollover stability in extreme steering operations and the vehicle lateral stability in normal steering operations. The relationships between vehicle stabilities in extreme and normal circumstances obtain less attention according to the present research works. In this paper, the coupling interactions between vehicle anti-rollover and lateral stability, as well as the effect of road excitation, are taken into account on the vehicle rollover analysis. The results in this paper indicate that some parameters influence the different vehicle stabilities diversely or even contradictorily. And it has been found that there are contradictions between the vehicle rollover mitigation performance and the lateral stability. The direct cause for the contradiction is the lateral coupling between tyres and road. Tyres with high adhesion capacity imply that the vehicle possesses a high performance ability to keep driving direction, whereas the rollover risk of this vehicle increases due to the greater lateral force that tyres can provide. Furthermore, these contradictions are intensified indirectly by the vertical coupling between tyres and road. The excitation from road not only deteriorates the tyres’ adhesive condition, but also has a considerable effect on the rollover in some cases.     

A yaw-moment control method based on a vehicle's lateral jerk information

Previously, a new control concept called ‘G-vectoring control (GVC)’ to improve vehicle agility and stability was developed. GVC is an automatic longitudinal acceleration control method that responds to vehicle lateral jerk caused by the driver's steering manoeuvres. In this paper, a new yaw-moment control method, which generates a stabilising moment during the GVC command and has positive acceleration value and the driver's accelerator pedal input is zero, was proposed. A new hybrid control, which comprises GVC, electric stability control and this new control, was constructed, and it was installed in a test vehicle and tested on a snowy surface. The very high potential for improvement in both agility and stability was confirmed.     

曲线地段非埋式桩板路基设计与计算方法研究

横向稳定性与抗变形能力是曲线段非埋式桩板路基的重要计算指标,深入分析这种结构的设计与计算方法十分必要。基于现有的简化计算方法,建立非埋式桩板结构的整体式平面计算模型,探讨了曲线段桩板结构的荷载力系,提出了其设计流程与计算方法。实践证明利用该设计计算方法可有效地获得满足工程精度要求的计算结果。     

Stability analysis of a nonlinear vehicle model in plane motion using the concept of Lyapunov exponents

For the first time, this paper investigates the application of the concept of Lyapunov exponents to the stability analysis of the nonlinear vehicle model in plane motion with two degrees of freedom. The nonlinearity of the model comes from the third-order polynomial expression between the lateral forces on the tyres and the tyre slip angles. Comprehensive studies on both system and structural stability analyses of the vehicle model are presented. The system stability analysis includes the stability, lateral stability region, and effects of driving conditions on the lateral stability region of the vehicle model in the state space. In the structural stability analysis, the ranges of driving conditions in which the stability of the vehicle model is guaranteed are given. Moreover, through examples, the largest Lyapunov exponent is suggested as an indicator of the convergence rate in which the disturbed vehicle model returns to its stable fixed point.