考虑模态因素的齿轨动车车体地板梁的结构拓扑优化

齿轨动车车体的轻量化是实现齿轨动车具有较强爬坡能力和舒适性等特性的关键因素之一。针对齿轨动车车体地板粱的轻量化设计,提出了一种基于模态分析、拓扑优化理论的二维与三维相结合的结构设计方法。首先,利用有限元法和结构优化设计软件对车体地板梁的二维截面进行了以应变能最小化的拓扑优化,获取了粗截面拓扑构型。然后,基于粗拓扑构型,以车体地板粱的三维结构为对象进行应变能最小化和模态最大化的多目标拓扑优化,得到了包含模态因素的地板粱的三维结构形状。最后,基于得到的两种优化结果与地板粱的可制造性,构造了一种适用于齿轨地板粱截面的新构型,并对其进行了与原结构相同边界条件下的有限元仿真对比分析和验证。结果显示该构型结构的强度、刚度及模态性能满足齿轨动车车体的要求,并且优化结构的质量较原结构下降了6.835%。

动车车体涂装漆面质量控制的方法研究

涂装漆面是构造车身美丽外形和耐用性的有效支撑,其质量的优劣直接关系车体的应用性能,尤其动车车身对于涂层的抗腐蚀性、抗划痕性及表面光洁度等均有较高的要求,文章将以涂装漆面现存问题为出发点,分析其形成的原因,并给出有效控制的方案,以为相关研究提供有效参考。

200km/h动车组车体底架端部结构优化设计

在分析某项目动车组车体端部结构的基础上,对200 km/h项目车体结构中核心承力部件———端部结构进行改进设计,以确保其具有更高的设计安全余量,承受更大载荷及适应更高速度要求。

Analysis theory of spatial vibration of high-speed train and slab track system

The motor and trailer cars of a high-speed train were modeled as a multi-rigid body system with two suspensions. According to structural characteristic of a slab track, a new spatial vibration model of track segment element of the slab track was put forward. The spatial vibration equation set of the high-speed train and slab track system was then established on the basis of the principle of total potential energy with stationary value in elastic system dynamics and the rule of ＂set-in-right-position＂ for formulating system matrices. The equation set was solved by the Wilson-θ direct integration method. The contents mentioned above constitute the analysis theory of spatial vibration of high-speed train and slab track system. The theory was then verified by the high-speed running experiment carried out on the slab track in the Qinghuangdao-Shenyang passenger transport line. The results show that the calculated results agree well with the measured rcsults, such as the calculated lateral and vertical rail displacements are 0.82 mm and 0.9 mm and the measured ones 0.75 mm and 0.93 mm, respectively; the calculated lateral and vertical wheel-rail forces are 8.9 kN and 102.3 kN and the measured ones 8.6 kN and 80.2 kN, respectively. The interpolation method, that is, the lateral finite strip and slab segment element, for slab deformation proposed is of simplification and applicability compared with the traditional plate element method. All of these demonstrate the reliability of the theory proposed.

Developing of the EV charging and parking shed of BIPV

Building-integrated photovoltaic(BIPV) is an important application way of solar photovoltaic power. The electric vehicle(EV) charging and parking shed of BIPV is the regeneration energy intellectual integration demonstration application system collection of photovoltaic(PV) grid power,PV off- grid power,EV charging and parking shed,and any part of the functions and their combination will be engaged in practical application on demand. The paper describes the PV shed system structure and design in detail with the present of its actual photos. The shed is 50 m long and 5.5 m wide and capable of parking 18 cars. Under the control of system intellectual controller,the power produced by PV from sunlight will charge the parking EV car prior to charging the storage battery,charging the storage battery prior to grid power,grid power at last,and charge the EV by utility grid when it is a cloudy or rainy day.

Application of DVA theory in vibration reduction of carbody with suspended equipment for high-speed EMU

The theory of dynamic vibration absorber(DVA)was applied to restrain the vibration of carbody for high-speed electric multiple unit(EMU).The carbody was modeled as an Euler-Bernoulli beam with the equipment mounted on the chassis regarded as a DVA.Suspension parameters of the equipment were optimized based on the modal analysis of the beam and parameter optimization of the DVA.Vertical motion equations of the carbody and equipment were derived to study the effect of the suspension parameters on the vibration of carbody,which included the suspension frequency,damping ratio,mounting position and mass.Then a 3D rigid-flexible coupled vehicle system dynamics model was built to simulate the response of carbody and equipment to track excitation.The results show that the equipment mounted on the carbody chassis can be regarded as a DVA to reduce the flexible vibration of carbody,and the optimum suspension frequency can be calculated theoretically with the first-order vertical bending mode of carbody considered.Heavy equipment should be mounted to the carbody center as close as possible to obtain a significant vibration reduction,while light equipment has quite limited contribution to that.Also,a laboratory test was conducted on the full-scale test rig which shows a good agreement with the theoretical analysis and dynamic simulations.The faster the vehicle runs,the more significant are the advantages of the elastic suspension.

Energy and environmental life-cycle assessment of passenger car electrification based on Beijing driving patterns

This paper examines the energy and environmental benefits within the whole life cycle shifting from traditional gasoline vehicles to electrified advanced vehicles under regional real-world driving behaviors. The advance vehicles focus on family passenger cars and include battery electric vehicles （BEVs）, plug-in hybrid electric vehicles （PHEVs）, and hybrid electric vehicles （HEVs）. The GREET （greenhouse gases, regulated emissions, and energy use in transportation） model is adopted with regional circumstances modifications, especially the UF （utility factors） of PHEVs. The results show that the electrified vehicles offer great benefits concerning energy consumption, greenhouse gas （GHG） emissions as well as urban Particulate Matter 2,5 （PMz.s） emissions. Compared to conventional gasoline vehicles, the life-cycle total energy reduction for advance vehicles is 51% to 57%. There is little difference on energy reduction among the HEVs, PHEVs and BEVs, with the energy mix shifting from petroleum to coal for the stronger electrification. The reductions of GHG emissions are 57% for HEV, 54% to 48% for PHEVs with 10 miles to 40 miles CD range, and 40% for BEV. The life-cycle and local PM2.5 emissions are discussed separately. The life-cycle PM2.5 emissions increase with vehicle electrification and reach a maximum for the BEV which are 5% higher than the conventional vehicle （CV）. However, electric vehicles can shift PM2.5 emissions from vehicle operation to upstream operations and help mitigate PM2.5 emissions in urban areas. The local emissions of PHEVs and BEVs can be reduced by 37% to 81% and 100% compared with CVs.