The purpose of this paper is to provide reference for safety warning and accident recovery of tank truck rollover. The calculation method of critical lateral acceleration of tank truck considering liquid sloshing is studied by combining analytical method and multi-body dynamics simulation method. In this paper, three methods are presented to solve the critical lateral acceleration of tank truck rollover considering liquid sloshing, which are analytical method, step steer simulation method and tilt table simulation method respectively. The liquid sloshing is simplified to two-dimensional liquid sloshing by assuming that the lateral acceleration of the tank truck is constant. The change of liquid center of gravity is used to be equivalent to the effect of liquid sloshing on tank truck rollover. The influence data of liquid sloshing, tire, suspension system and tank truck center of gravity on the rollover of tank truck were obtained. The research results can be applied to the safety warning and accident recovery of tank truck.
In order to obtain the structure of electromagnetic boiler heater with maximum heat exchange efficiency, five parameters of heater: heating rod diameter, heating rod uniform distribution diameter, heating rod uniform distribution angle, non-metallic shell inner wall diameter and non-metallic shell wall thickness were selected as design parameters. Based on the multi-physical field coupling calculation, the response surface model and genetic algorithm were used to optimize the design parameters of the heater, and the structural parameters with the highest heat transfer efficiency were obtained. The heat transfer efficiency of the optimized heater reached 97.8 %, which was 5.8 % higher than that of the prototype heater structure.
中间防爬器是安装于列车各车厢连接位置界面的被动安全防护装置,用于吸收意外碰撞事故中的冲击能量.为验证所研制的某型列车中间防爬器是否满足轨道车辆装车的严苛性能要求,根据《EN15227:铁路应用-铁路车辆车体的耐碰撞性要求》的标准要求,对导向蜂窝式防爬器产品样件的结构性能及吸能性能进行系统的试验研究.研究结果表明,该导向蜂窝式防爬器产品满足垂向承载性能测试、静压测试、撞击刚性墙、错位40 mm对撞测试等性能要求.
拨叉零件是构成车床变速机构的重要零件,其主要作用是通过拨叉使两根不同速度的轴上的齿轮匹配以获得不同的转速,从而实现变速.该文首先简要分析了拨叉零件的结构并根据拨叉的技术要求确定了毛胚尺寸和机械加工余量,然后通过方案的对比分析确定了最优加工方案并制订了加工工艺路线.最后,为拨叉通槽加工设计了铣床专用夹具,此夹具结构简单、能快速装夹,不仅能保证产品质量,还可提高生产效率.
