巴哈赛车转向系统设计

大学生巴哈比赛是一项由汽车工程学会主办以大学生群体为主的赛车竞赛。要求在规定时间内每支车队独立制造出一辆具有良好的加速性能、四轮能同时抱死、操控性能足够稳定等特点以成功通过赛事里的每一项比赛的赛车。转向系统设计是巴哈赛车设计中的一项非常重要设计,其作用是保障在改变行驶方向的同时保证车辆的正常运行,并保证在产生转向时转向轮之间的转角协调.本文简要分析了转向系统的作用、基本构成,为了保证赛车具有良好的机动性能,确定符合巴哈赛车的最小转弯半径,最大外轮转角以及转动系统的传动比;其次根据赛车所需转向关系以及实际转向内外轮转角关系确定转向梯形结构参数并验证其是否满足要求,利用前悬架参数采用三心定理确定转向梯形断开点,确定转向杆系的空间布局;最后确定各结构件参数完成catia三维模型建立装配。     

基于CBR的泥石流区域铁路选线方案辅助决策模型研究

为了将历史泥石流区域选线案例应用于拟建川藏铁路泥石流区域选线方案的决策中,建立基于案例推理的艰险山区泥石流区域选线方案辅助决策模型.首先选取数个特征属性对泥石流案例进行定量表示,并运用梯形模糊层次分析法为各特征属性赋权;而后根据历史工程案例资料建立了艰险山区泥石流灾害案例库,在此基础上,利用灰色关联方法进行相似案例的检...     

Response of carbon fiber trapezoidal corrugated sandwich structure under air explosion loading北大核心CSCD

The effects of the thickness of the face plate, angle of the wall plate and height of the core layer on the anti-explosion performance of carbon fiber reinforced composite trapezoidal corrugated sandwich structures were investigated. [Methods]First, based on the 3D Hashin failure criterion, a subroutine module of the damage evolution of fiber reinforced composites is developed using the VUMAT user subroutine interface in ABAQUS. Second, through comparison with experiments in the public literature, the effectiveness of the dynamic response simulation method of carbon fiber reinforced composites based on a development subroutine under explosion impact loading is verified. Finally, a parametric study on the explosion resistance of carbon fiber reinforced composite trapezoidal corrugated plates is carried out based on the numerical method. [Results]The results show that, compared with increasing the thickness of the blast face panel, increasing the thickness of the back blast face panel can improve the explosion resistance of the sandwich plate more obviously; when the folding angle of the core wall plate decreases from 45° to 30°, the explosion resistance increases by 1.3%; when it decreases from 60° to 45°, the explosion resistance increases by 6.3%; and whenthecoreheightincreasesfrom8mmto20mm, theexplosionresistanceincreasesby27.7%.[Conclusions]The results of this study can provide references for the explosion-proof design of carbon fiber reinforced composite sandwich structures. © 2023 Journal of Nanjing Agricultural University. All rights reserved.     

举升电动缸用梯形丝杠副胶合现象分析

针对某举升电动缸用梯形丝杠副在实际使用过程中发生的胶合现象，从载荷、速度、润滑和使用频率等方面分析，寻找造成该现象的原因。基于所述因素的分析，采取对应整改措施，以改善甚至消除丝杠副胶合现象。研究内容对于类似梯形丝杠副的设计、使用及维护具有一定的参考意义。