中文摘要：

为了改善某底架承载式机车的刚度性能,使其重量、强度、刚度达到最优匹配,推导了一种鱼腹型中梁的优化设计解析方法。首先,将承载中梁等效成简支梁,采用积分法获得通用挠曲线方程;然后,应用Matlab软件编程计算不同变截面形状下的中梁挠度解析解,并分析不同方案下最大截面高度、起点值、跨度值对中梁挠度和质量的影响,以降低中梁10%挠度为主要目标,确定最优变截面形状;最后,利用有限元分析软件ANSYS对最终确定的鱼腹型中梁设计方案与原方案下车体静强度和模态进行对比分析。研究结果表明,基于力学解析的变截面设计方法可以用于底架承载式机车鱼腹型中梁的快速设计,该理论方法可以在兼顾底架重量最优的同时,对中梁的变截面进行精确控制与设计,从而提高底架的刚度性能。

英文摘要：

For an optimal combination of weight, strength and stiffness of locomotive vehicle body, a mechanical analysis method was used to optimize the variable cross-section longitudinal beam of underframe bearing type locomotive. Deflection equations were obtained by means of integrating theory, on the premise that the longitudinal beam was equivalent to simply supported beam. Then, based on the analytical solution which was calculated in Matlab program, impact factors such as maimum height of section, starting-point and length span, was analyzed to get a 10% lower deflection. At last, strength and modal analysis of the orinal and new models was obtained by finite element analysis. It was shown that, the mechanical analysis method can rapidly realize the precisely control and design of variable cross-section longitudinal beam, and make the quality and stiffness strength achieve the optimum.