基于响应面法的超高压柱塞泵缸套优化设计

Optimization Design of Cylinder for Ultra-High Pressure Plunger Pump Based on Response Surface Method

超高压柱塞泵缸套在工作过程中承受脉动载荷作用,设计过程中需要考虑其疲劳寿命对可靠性的影响。根据缸套的结构形式和载荷特点,得到了脉动应力的幅值和影响因素。基于自紧增强理论设计了一种分层套接缸套结构,并分析了尺寸参数、材料性能以及过盈量对高压工作状态下内壁面切向应力的影响规律。在不改变缸套外形尺寸以及功能的前提下,以套接尺寸和过盈量为设计变量,以工作状态下缸套内壁最大切向应力等于0为目标,结合响应面法和APDL模型进行优化设计,得到了设计参数组合并验证其输出值的准确性。结果表明选取合适的套接设计尺寸可大幅降低内壁面的切向应力脉动幅值,且平均应力为压应力,进而提高了缸套的疲劳寿命。

The cylinder is the key component of the ultra-high pressure plunger with pulsating load during working process,and the influence of fatigue life on reliability should be considered in the design process.According to the structure and load characteristics of the cylinder,the amplitude and influencing factors of the pulsating stress were obtained.Based on the theory of autofrettage reinforcement,a double-layers cylinder was designed,and the influence of dimensional parameters,material properties and interference on the tangential stress of the inner wall surface under high pressure was analyzed.Without changing the size and function,the layer sizes and interferences were used as design variables,and the maximum tangential stress of the inner wall equal to 0 was set to be the target under working conditions.The response surface method and APDL model were combined for optimization to get the parameters combination with its accuracy verified.The results show that the appropriate sizes of the layers could greatly reduce the tangential stress fluctuation amplitude of the inner wall surface,and the average stress is converted to compressive stress,which will increasing the fatigue life of the cylinder.