摘要
有限元方法应用于活塞结构设计主要存在两方面的局限性,即热边界条件的不确性和复杂三维应力状态下活塞热疲劳结构的评价。论文利用残余硬度法对活塞温度场分布状态准确反映的特点,以此对活塞各表面传热系数进行调校和修正,通过有限元法获得内冷油腔活塞较为准确的温度及温度梯度的分布;并可由有限元法得出机械—热载荷作用下的活塞轮廓变形线,将之再与活塞与气缸理想间隙配合状态下活塞的型线叠加而成活塞初始外周轮廓型线的设计;同时应用应力—温度散点图的评价方法,能够直观地反映温度因素对活塞结构强度的影响,并可通过有限元法详细的三维应力和温度分布数据对活塞实际结构进行校核和评价,将其应用于近年中吨位车用增压柴油机振荡内冷油腔活塞的研发,取得良好效果。
The development of FEM（finite element method） applied to pistons design nowadays is strongly limited due to the uncertainty of thermal boundary conditions and the difficulty of structure fatigue evaluation under three-dimensional stress status in high temperature condition.Therefore,the test results of residual hardness method were introduced to calibrate the heat transfer coefficients of piston surfaces,so that temperature as well as temperature gradient of a piston with inner oil-cooling channel can be accurately obtained by FEM.Moreover,based on the calculated deformation of the piston under thermal loads and mechanical loads,the profile of piston skirt can be primarily designed to keep the ideal piston skirt clearance.While the evaluation method of stress-temperature point clouds,which can effectively verify the structural strength of piston using stress field and temperature field obtained by FEM was adopted and it has been successfully applied to the development of pistons with inner oil-cooling channel for turbocharged diesel engine in recent years.
出处
《机械强度》
CAS
CSCD
北大核心
2011年第3期390-395,共6页
Journal of Mechanical Strength
基金
国防基础科研项目(C1020060350)
重庆市自然科学基金资助项目(2007BA6026)
重庆市科技攻关计划项目(2008AA6024)资助~~
关键词
活塞
有限元法
温度场
热变形
强度
Piston
Finite element method
Temperature field
Thermal displacement
Structural strength
