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41.
Korang Modaressi-Tehrani S. Rakheja I. Stiharu 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2007,45(6):525-548
The directional dynamic analyses of partly-filled tank vehicles have been limited to quasi-static fluid motion due to computational complexities associated with dynamic fluid slosh analyses. The dynamic fluid slosh causes significantly higher magnitudes of slosh forces and moments in the transient state that cannot be characterized through quasi-static approach, which provides reasonably good estimates of the mean responses. In this study, a three-dimensional nonlinear model of a partly-filled cylindrical tank with and without baffles is developed to investigate the significance of resulting destabilizing forces and moments caused by the transient fluid slosh, and the effects of baffles. The baffles and the end caps are modeled with curved shapes. The analyses are performed under varying magnitudes of steady lateral, longitudinal and combinations of lateral and longitudinal accelerations of the tank, and two different fill volumes using the FLUENT software. The results of the study are presented in terms of mean and peak slosh forces and moments, and variations in the mass moments of inertia of the fluid cargo within a clean bore and a baffled tank, for two different fill volumes and different magnitudes of acceleration excitations. The ratios of transient responses to the mean responses, termed as amplification factors, are further described to emphasize the significance of dynamic fluid slosh on the forces and moments induced on the vehicle. The results in general suggest that the mean responses attained from dynamic fluid slosh analyses correlate well with those attained from the quasi-static analyses for a clean bore tank. The amplification ratios of the resulting forces and moments could approach as high as 2. The results clearly show that the presence of baffles helps to suppress the peak as well as mean slosh forces and moments significantly. 相似文献
42.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(6):525-548
The directional dynamic analyses of partly-filled tank vehicles have been limited to quasi-static fluid motion due to computational complexities associated with dynamic fluid slosh analyses. The dynamic fluid slosh causes significantly higher magnitudes of slosh forces and moments in the transient state that cannot be characterized through quasi-static approach, which provides reasonably good estimates of the mean responses. In this study, a three-dimensional nonlinear model of a partly-filled cylindrical tank with and without baffles is developed to investigate the significance of resulting destabilizing forces and moments caused by the transient fluid slosh, and the effects of baffles. The baffles and the end caps are modeled with curved shapes. The analyses are performed under varying magnitudes of steady lateral, longitudinal and combinations of lateral and longitudinal accelerations of the tank, and two different fill volumes using the FLUENT software. The results of the study are presented in terms of mean and peak slosh forces and moments, and variations in the mass moments of inertia of the fluid cargo within a clean bore and a baffled tank, for two different fill volumes and different magnitudes of acceleration excitations. The ratios of transient responses to the mean responses, termed as amplification factors, are further described to emphasize the significance of dynamic fluid slosh on the forces and moments induced on the vehicle. The results in general suggest that the mean responses attained from dynamic fluid slosh analyses correlate well with those attained from the quasi-static analyses for a clean bore tank. The amplification ratios of the resulting forces and moments could approach as high as 2. The results clearly show that the presence of baffles helps to suppress the peak as well as mean slosh forces and moments significantly. 相似文献
43.
从移动闭塞的功能出发,阐述了广州地铁3号线ATC系统的列车定位技术。3号线信号系统以交叉感应环线为车-地通信介质,列车定位方面采用交叉感应环线进行粗略定位,采用车载测速发电机进行精确定位,同时还采用接近传感器进行站台辅助定位。此外还对定位技术中的抗干扰屏蔽、轮径补偿和空转及打滑监测等作了阐述。 相似文献
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为解决整车试制阶段,在检具和支架还没有开发出来的情况下,活动件(电动玻璃升降器系统、车身铰链系统、雨刮电机及连动杆系统和天窗系统等)尺寸控制分析困难的现状,应用DMU(Digital Mock Up,数字装配)运动机构动态仿真技术,通过对活动件开合角度的调整,结合现有的三维测量技术,有效地解决了车身试制阶段,活动件尺寸分析困难的问题。活动件尺寸工程上的DMU应用技术,可以实现整车试制阶段活动件尺寸精准测量分析。 相似文献
46.
双横臂独立悬架运动特性分析 总被引:9,自引:1,他引:9
几何参数是影响双横臂独立悬架运动特性的最重要因素。用矢量方法推导双横臂独立悬架运动特性,建立了上、下控制臂球头中心的运动方程以及转向系和悬架的运动协调方程;从工程设计的实际需要出发,编写了悬架运动特性的计算程序,使用 ADAMS软件和本程序进行了计算对比,以验证程序的正确性,并运用该程序对 CA6440和 CA6471的双横臂独立悬架进行了计算分析。 相似文献
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移动荷载作用下近桥台处路面结构动力响应的有限元法分析 总被引:8,自引:0,他引:8
应用ABAQUS有限元建立了桥台后路堤路面动力计算的三维模型,将车辆荷载表达为反复移动的分布荷载(移动荷载)形式,并编制了VDLOAD子程序。通过有限元Explicit计算模块,首先分析了行车速度、材料阻尼比与轮胎压力对路面结构动响应的影响;其次,着重分析了车速90km/h、阻尼比5%、胎压700kPa条件下单次与多次循环荷载作用下路面动应力与位移的变化规律。分析认为,随着开放交通后道路使用时间的增长,路桥过渡段差异沉降的累积将导致近桥台处路面结构损坏程度加剧,从而影响道路的正常使用。 相似文献
48.
文章针对钢桥面铺装体系受力复杂、铺装表面承受较大的弯拉应力、钢桥面铺装使用的荷载与温度条件相对恶劣等情况,对钢桥面沥青铺装表面的拉应力进行了粘弹性有限元计算分析,介绍采用粘弹性材料模型,利用试验数据计算得到的材料计算参数,为铺装设计提供参考。 相似文献
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This study investigates how highway nuisances are traded off against accessibility gains and other residential characteristics in the moving intentions of people living near highways. It studies a potential mediating role for residential satisfaction and potential mitigating relationships with highway nuisance perceptions. Structural Equation Modelling was used to test a proposed framework based on survey data collected from 1220 respondents living within 1000 m from a highway in the Netherlands.The results show that higher levels of perceived highway nuisances are associated with increased intentions to move, mediated by lower residential satisfaction. However, better perceived accessibility was not associated with either lower moving intentions or lower highway nuisance perception. Highway usage/interest and other residential characteristics – such as satisfaction with buildings, traffic safety, and amount of greenery – seem to countervail perceived highway nuisances as they reduce moving intentions and reduce highway nuisance perception. Finally, the results show that some groups – for example home owners – were less inclined to move (direct effect), independently of their residential satisfaction.From a practical perspective, a more inclusive perspective on highway planning, which accounts for accessibility and other residential characteristics as potential compensators and mitigators for highway nuisances, would be effective to reduce residential stress which could prevent protest and consequent cost overruns of projects. 相似文献