摘要
根据P91材料高温等时应力应变本构关系,对高温含内局部减薄缺陷弯管的蠕变极限载荷进行了研究。研究表明,高温蠕变极限载荷在蠕变初期急剧下降,之后下降趋缓,该现象反映了高温下材料蠕变劣化过程。不同应变准则下蠕变极限载荷变化规律一致。根据有限元计算结果,提出了与蠕变时间无关的蠕变极限载荷计算方法,得到了含内局部减薄缺陷高温弯管的安全评定方法。
Based on high temperature isochronous stress-strain curves of P91 steel, the creep limit load of pipe bends with inner local wall thinning defect was studied by finite element analysis. The results show that at the beginning of the creep stage, the creep limit load has a sharp drop, afterwards, and it then declines gently, which shows creep degradation process of high temperature material. The trends of the creep limit load variation according to different strain criterions are basically agreement. Based on the finite element results, the time-independent creep expressions are proposed, and the safety assessment method of pipe bends with inner local wall thinning defect at high temperature is acquired.
出处
《机械强度》
CAS
CSCD
北大核心
2015年第2期348-354,共7页
Journal of Mechanical Strength
基金
江苏省自然科学基金资助项目(BK2008373)资助~~
关键词
高温
局部减薄
弯管
蠕变极限载荷
有限元
High temperature
Local wall thinning
Pipe bends
Creep limit load
Finite element
