单自由度自动翻转平台力学特性研究

目的 提出一种单自由度自动液压翻转平台，综合分析其力学特性，验证是否适用于固体火箭发动机振动试验换向过程。方法 根据液压设计理论，推导液压缸伸缩位移与翻转角度的数学关系，通过对翻转架进行静力学分析，确定翻转平台的极限受力位置，并解析受力与翻转角度之间的具体关系。针对极限受力位置的翻转架连同机架联合体，进行静应力分析，验证其稳定性。结果 翻转架处于初始水平位置时，液压缸承受最大压力，翻转角度为90°时，液压缸受拉轴向力出现最大值。翻转架的应力分布不均匀，应力最大值出现在其中部，最大应力值远小于许用应力，其强度满足应用要求。结论 翻转平台的力学性能满足设计和使用要求。另外，极限位置静力学受力分析和运动过程分析的结合评价方法，能够合理判定轴支撑翻转类机械装备的力学性能。

Mechanic Property of Automatic Overturning Platform with Single Degree of Freedom

The work aims to propose an automatic hydraulic overturning platform with single degree of freedom to comprehensively analyze its mechanical characteristics, and verify whether it is suitable for the reversing process of solid rocket motor in vibration tests. According to the hydraulic design theory, the mathematical relationship between the telescopic displacement of the hydraulic cylinder and the overturning angle was derived. Through the statics analysis of the overturning frame, the ultimate stress position of the overturning platform was determined, and the specific relationship between the stress and the overturning angle was analyzed. A static stress analysis was carried out to verify the stability of the overturning frame and the frame combination at the ultimate stress position. When the overturning frame was in the initial horizontal position, the hydraulic cylinder bore the maximum pressure, and when the overturning angle was 90°, the axial force of the hydraulic cylinder under tension appeared the maximum value. The stress distribution of the overturning frame was uneven, with the maximum stress appearing in the middle, which was much smaller than the allowable stress, and the strength met the application requirements. The mechanical performance of the overturning platform meets the design and usage requirements. In addition, based on the combined evaluation method of static force analysis on its extreme positions and analysis on the process of its motion, the mechanical performance of shaft supported overturning mechanical equipment can be reasonably determined.