重载轨道车辆非线性结构设计

Nonlinear structure design of heavy haul vehicle

为减轻重载轨道车辆质量,提高车辆的承载能力,对于采用具有强化效应高强度低合金钢的车辆结构,按材料非线性理论,允许结构局部塑性变形,进行结构轻量化设计,采取弱化端墙、强化底架的结构优化措施,并采用几何非线性理论对其进行非线性稳定性分析。按此非线性分析方法,对新研发的轴载40 t、总载160 t的重载敞车进行了车体结构优化设计。在纵向压缩工况下,优化后车体结构最大应力为336 MPa,小于材料Q450NQR1屈服强度450 MPa,发生局部屈曲的最小临界载荷Fcr为6 252 kN。在纵向冲击工况下,车体的大应力点分布在上侧梁和上端梁区域,应力值达到530 MPa左右,仍低于材料的极限强度550 MPa,且底架上的应力分布较优化前更均匀。车体结构的强度、刚度及稳定性符合AAR标准规范要求,车辆自重系数仅为0.16。分析结果表明非线性分析方法是重载车辆结构轻量化设计的有效手段。

Based on material nonlinear theory and local plastic deformation being allowed,structure lightweight design were carried out in order to relieve the mass and increase the load-carrying capacity for heavy haul railway vehicle,which was made of high strength low-alloy steel with strengthening characteristic.The optimization measures to weaken the end-wall and strengthen under-frame structure were taken.Furthermore,the nonlinear stability analysis of the lightening structure was put up using geometric nonlinear theory, and was used to develope an optimization new-type 40 t-axle-load heavy haul gondola car whose total mass is 160 t. Under longitudinal compress load case, the maximum stress is 336 MPa, which is less than the yield stress 450 MPa of Q450NQR1 material, and the critical load of local buckling occurrence is 6 252 kN. Under longitudinal impact load case, some stresses are about 530 MPa located on top side cant and end cant, which are below the limited stress 550 MPa, and the stresses on under-frame are more uniformity than that before the optimization. The strength, stiffness and stability of the car meet the demand of AAR criterion, and the deadweight coefficient is only 0.16. The result shows that nonlinear analysis method is a valid instrument of lightweight design of heavy haul vehicle. 1 tab, 14 figs, 13 refs.