摘要
采用"无限大板"中孤立小孔应力集中方法,建立了一种新的以特征参数λ表征的厚壁单胞体接触应力理论模型;以高温发汗润滑体为对象,采用该模型仿真分析了单胞体在特征参数λ≤0.4情况下的胞内应力分布状态。结果表明:随着外载荷的增大,接触半径逐渐增大,且接触区域的各向应力(绝对值)均逐渐变大;最大剪应力逐渐从胞体表面向胞体内部迁移,其y向最大应力从接触中心逐渐向孔边θ=0和θ=-π,r=r2处转移,x向最大应力从接触中心逐渐向孔边θ=-π/2,r=r2处转移;该应力集中区逐渐取代胞体接触表面而成为微裂纹诱发源。λ对胞体接触应力分布也有很大影响:当λ=0.4时,孔穴应力集中区与胞体接触区的y向应力差值最大;当λ=0.1时,两处的x向应力差值最大;当外载荷大于1000N时,λ=0.2的胞体内的最大剪应力具有最小值。
A new thick wall of single-cell contact theoretical model was developed with the stress concentration method of isolated hole in ＂infinite board＂and the characteristic parameters of λ, and the high-temperature sweating and self-lubricating materials were taken as an example to simulate and analyze the intracellular stress distribution of single cell body within the scope of λ〈0.4〈0.5 based on the model. The results show that. As the load increasing, the contact radius increases gradually and all of the stress in the contact region become bigger gradually; the maximum of shear stress gradually migrates from the cell surface to the internal cell, while the greatest of y-stress transfers from the contact center to the θ= 0 and θ=- π, r= r2 of the pore; and the maximum of x-stress transfers from the contact center to the θ=- -π/2, r= r2 of the pore;the stress concentration area gradually replaces the contact surface to be the source inducing micro-cracks. The parameters of A also has a great influence on the contact stress distribution, when λ = 0.4, the y- stress margin of the pore stress concentration region and the contact region is the largest; while λ = 0. 1, the x- stress margin of these two places is the largest; when loads is greater than 1000N and ;λ=0.2,the maximum of shear stress is the minimum.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2008年第24期2982-2986,共5页
China Mechanical Engineering
基金
国家自然科学基金资助项目(50775168)
高等学校博士学科点专项科研基金资助项目(20070497105)
关键词
高温发汗润滑体
单胞接触
孔穴
应力分析
high- temperature sweating and self- lubrication material
single- cell contact
pore stress analysis
