Hierarchical optimisation on scissor seat suspension characteristic and structure

Scissor seat suspension has been applied widely to attenuate the cab vibrations of commercial vehicles, while its design generally needs a trade-off between the seat acceleration and suspension travel, which creates a typical optimisation issue. A complexity for this issue is that the optimal dynamics parameters are not easy to approach solutions fast and unequivocally. Hence, the hierarchical optimisation on scissor seat suspension characteristic and structure is proposed, providing a top-down methodology with the globally optimal and fast convergent solutions to compromise these design contradictions. In details, a characteristic-oriented non-parametric dynamics model of the scissor seat suspension is formulated firstly via databases, describing its vertical dynamics accurately. Then, the ideal vertical stiffness-damping characteristic is cascaded via the characteristic-oriented model, and the structure parameters are optimised in accordance with a structure-oriented multi-body dynamics model of the scissor seat suspension. Eventually, the seat effective amplitude transmissibility factor, suspension travel and the CPU time for solving are evaluated. The results show the seat suspension performance and convergent speed of the globally optimal solutions are improved well. Hence, the proposed hierarchical optimisation methodology regarding characteristic and structure of the scissor seat suspension is promising for its virtual development.     

Optimisation of active suspension control inputs for improved vehicle handling performance

Active suspension is commonly considered under the framework of vertical vehicle dynamics control aimed at improvements in ride comfort. This paper uses a collocation-type control variable optimisation tool to investigate to which extent the fully active suspension (FAS) application can be broaden to the task of vehicle handling/cornering control. The optimisation approach is firstly applied to solely FAS actuator configurations and three types of double lane-change manoeuvres. The obtained optimisation results are used to gain insights into different control mechanisms that are used by FAS to improve the handling performance in terms of path following error reduction. For the same manoeuvres the FAS performance is compared with the performance of different active steering and active differential actuators. The optimisation study is finally extended to combined FAS and active front- and/or rear-steering configurations to investigate if they can use their complementary control authorities (over the vertical and lateral vehicle dynamics, respectively) to further improve the handling performance.     

关于悬挂点焊机焊点过烧的分析

在汽车的制造生产过程中,白车身总成的焊接通常使用悬挂点焊机进行驾驶室的焊接,点焊属于压力焊的一种,然而在焊接过程中易出现焊点过烧(俗称炸点)的现象,对焊接质量造成一定的影响,也会对人身安全造成一定的伤害.本文主要介绍在悬挂电焊机出现过烧问题时的分析与故障排查.     

磁浮车不能稳定悬停在钢轨道框架上的原因分析

磁浮车辆不能稳定悬停在钢轨道框架上的原因,是由于钢轨道框架的自振频率与磁浮车的振动频率相近而引起的。用ANSYS软件分析了两种不同钢轨道框架的自振频率及模态。通过改变钢轨道框架立柱的侧向刚度,可以使结构的固有频率避开磁浮车的失稳频率敏感区。     

大跨度悬索桥丝股架设线形计算的精确方法

根据悬索桥的施工特点及实际施工情况,探讨了悬索桥丝股架设线形计算的精确方法,分析了悬索桥丝股架设时索鞍的最佳平衡条件,建立了丝股架设时索鞍的理想位置－预量的理论计算方法,本文的方法不存在用有限元法计算时的那种偏设误差,它根据力学平衡条件和变形相容条件确定各部分的索力和曲线形状,自动计入了索曲线的所有非线性,与有限元法相比,计算精度大为提高。     

感应数据传输及其在磁悬浮列车通信系统中的应用

采用矩量法计算了两个不等长不平等导线在任意位置耦合的电流分布、自阻抗和互阻抗。利用等效二端口网络求出了导线上的感应电压,分析了耦合强度随距离的变化情况,并指出这种耦合方式可以用于磁悬浮列车数据传输。     

张家界大峡谷玻璃桥桥塔设计

张家界大峡谷玻璃桥为主跨430 m的空间索面人行悬索桥,集旅游、景观、娱乐、休闲于一体.考虑张家界"峰林"地貌,桥塔采用圆环形钢筋混凝土独柱结构,塔柱间不设横梁.西北侧、西南侧、东北侧、东南侧塔柱高度分别为40.65,40.65,37.15,40.15 m.东、西侧两塔柱间的横向中心距分别为50 m和45 m,每根塔柱...     

独塔非对称自锚式悬索桥合理约束体系研究

自锚式悬索桥通过主缆与加劲梁锚固结合的方式,形成闭合传力路径。主缆的水平分力通过锚固区逐渐传递到主跨加劲梁,竖向分力则主要通过边跨自重平衡。在静力情况下,主梁为超静定体系;在动力情况下,通常为全漂浮或者半漂浮体系来达到减隔震目的。这样就会造成主梁约束转变的情况,这个问题在独塔非对称自锚式悬索桥中尤为凸显。本文以太原市通达街跨汾河的四跨独塔非对称自锚式悬索桥为背景工程,建立全桥有限元模型,分析了全桥在静力及动力情况下不同约束体系对全桥受力的影响,为今后同类型结构设计提供依据。     

环湖绿道红星坪悬索桥总体设计

红星坪悬索桥桥梁总长232 m,主桥为双塔单跨悬索桥,主跨为222 m,垂跨比1/10.2;桥面宽度6 m,净宽4.8 m。索塔采用钢筋混凝土塔柱;主缆及抗风缆锚碇采用重力锚;加劲梁采用分离式钢箱梁,上、下游设置抗风缆。通过详细阐述人行悬索桥的总体设计要点,结构设计关键节点,为后续类似项目提供指导。     

基于影响矩阵法的自锚式悬索桥施工张拉力确定

自锚式悬索桥施工过程中,控制吊杆施工张拉力,使桥梁在施工完毕后达到理想的设计状态.文中结合自锚式悬索桥施工过程中的力学特性,提出了基于几何线性、几何非线性的影响矩阵法确定自锚式悬索桥的施工张拉力.该方法计算简单,所得结果符合要求.