中文摘要：

通过分析U形副构架的受力,给出其横向和纵向刚度的计算式以及设计流程.视U形副构架为柔性体,构建刚柔耦合车辆动力学模型,动态优化计算U形副构架刚度取值范围;当连接杆采用非标准件使刚度变化时,利用轮对径向装置的横向刚度和纵向刚度的计算公式,对U形副构架刚度进行修正.以我国新造27 t轴重货车为例,采用SIMPACK动力学软件分析U形副构架刚度对车辆运行性能的影响.结果表明：在保证车辆稳定性和直线通过性能的前提下应尽可能降低U形副构架的横向和纵向刚度;U形副构架的横向刚度应控制在14～33 MN·m-1范围内,纵向刚度的取值应在10 MN·m-1以上;连接杆作用力的频率小于12 Hz,远小于U形副构架的模态频率,因此不会引起U形副构架的结构共振;理论计算得到U形副构架的横向和纵向刚度值分别为17和10 MN·m-1,试验得到的测试值分别约为16.84和9.88 MN·m-1,验证了设计方法的正确性.

英文摘要：

Based on the force analysis of U-type sub-frame,the formula and design flow was proposed for its lateral stiffness and longitudinal stiffness.Regarding U-type sub-frame as a flexible body,the rigidflexible coupling vehicle dynamic model was established to dynamically optimize and calculate its stiffness range.If the stiffness of cross rod was different due to a nonstandard part,the calculated stiffness of U-type sub-frame would be revised by the formula for the lateral or longitudinal stiffness of wheelset radial device.Taking the new type of freight car with 27 t axle load in China for example,the influence of U-type sub-frame stiffness on vehicle operation performance was analyzed by SIMPACK dynamics software.The results show that it is better to reduce as possible the lateral and longitudinal stiffness of U-type sub-frame if vehicle stability and negotiation performance on straight lines can be ensured.According to simulation results,the lateral stiffness of U-type sub-frame should be controlled within the range of 14～33 MN · m-1 and its longitudinal stiffness should be over 10 MN · m-1.Since the frequency of cross rod force is less than 12 Hz,which is much smaller than the modal frequency of U-type sub-frame,the structural resonance can be avoided.The lateral and longitudinal stiffness of U-type sub-frame obtained by theoretical calculation is 17 and 10 MN · m-1 respectively,and that obtained from tests is 16.84 and 9.88 MN · m-1 respectively,which has validated the correctness of the design method.