摘要
推导内外压载荷下梯度材料球罐与时间相关行为的解析公式,在此基础上分别分析弹性梯度分布和蠕变梯度分布对球罐蠕变应力应变的影响。计算结果表明弹性参量的梯度变化只对蠕变初始阶段应力分布有影响,当蠕变应力达到稳态值后,球罐中的应力水平将只取决于蠕变参量的梯度分布:而蠕变应变分布则同时与材料的弹性和蠕变两种梯度变化有关。就降低梯度材料球罐蠕变应力应变值进行探讨,为梯度材料球罐的结构设计和优化提供基本的理论依据。
The creep behavior of a spherical vessel composed with the functionally graded material is derived under the internal and external pressure. The effects of elastic and creep graded distributions on the time-dependent stress/strain are systematically analyzed. The numerical results show that the elastic distribution only affects the stress development at the initial creep stage. When the stress reaches the steady state its magnitude is only related to the graded creep property distribution inside the vessel. However the variation of the creep strain is both determined by the graded creep property distribution and the graded elastic pattern. The different gradient distributions are further discussed to reduce the creep stress and strain along the wall thickness. The research work performed can be used to guide the structural and optimum design of functionally graded material spherical vessel.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2008年第3期89-93,共5页
Journal of Mechanical Engineering
基金
国家自然科学基金(50225517
50505012)
教育部霍英东青年教师基金(101054)
上海启明星(05QMX1416)资助项目。
关键词
梯度材料
球罐
蠕变
应力
应变
Functionally graded material Spherical vessel Creep Stress Strain
