多荷载联合作用下含穿透裂纹接管安全评定

对多种荷载联合作用下含缺陷压力容器的安全评定目前仍无可靠方法.采用三维有限元方法,对含肩部穿透裂纹接管在内压和弯矩联合作用下安全评定所需的断裂比和荷载比进行求解.研究表明,断裂比可根据内压和弯矩作用下裂纹的应力强度因子KIs得到,KIs为仅受内压下应力强度因子与仅受弯矩下应力强度因子的线性加和.荷载比由实际外载、内压作用下接管极限内压p与弯矩作用下极限弯矩m求出,给出了内压和弯矩联合作用下接管极限荷载与p、m的关系.所得结论可用于内压和弯矩作用下含肩部穿透裂纹接管的安全评定.

Safety assessment for nozzle containing through-wall crack under multiple loads

There are still no reliable approaches to safety assessment on pressure vessels containing defects under multiple loads now.The 3D finite element method was adopted to calculate fracture ratio and load ratio used in safety assessment for nozzle containing through-wall crack at the shoulder under the combination of internal pressure and moment.Research results indicate that fracture ratio can be obtained by the stress intensity factor K_Is of crack under internal pressure and moment,which is the summation of stress intensity factor of crack under internal pressure and that under moment.Load ratio can be obtained by actual external loads,limit internal pressure p and limit moment m,and the relation between p and m fits the linearity equation.Therefore,safety assessment of nozzle containing through-wall crack at the shoulder under internal pressure and moment can be accomplished.