基于压力容器规范的平盖与圆筒锁底对接焊结构强度研究

Research on Strength of Butt Welded Structure of Flat Cover and Cylinder Lock Bottom Specified in Pressure Vessel Codes and Standards

平盖结构特征系数是决定平盖设计厚度的一个关键系数。对比各个设计规范,发现同是锁底对接焊,不同规范甚至同一规范不同版本所选择的结构特征系数都有很大的不同,因此,研究平盖与圆筒锁底对接焊结构的强度具有重要意义。使用ANSYS软件进行有限元分析,利用极限分析法得到不同尺寸结构下极限载荷,并与其设计压力做比较,得到不同结构、不同尺寸参数下结构的强度裕度。结果表明:对于两种不同的平盖与圆筒锁底对接焊结构,在不同结构尺寸下,GB 150-1998与GB/T 150-2011对于平盖结构特征系数的选取存在冒进、材料浪费或过于保守的情况。

Flat head structure characteristic coefficient is a key factor in determining flat head thickness,but the coefficients are different in different design codes and standards,and even with different versions of the same standards,this coefficients will be different.Therefore,it is of great significance to study the strength of the butt welded structure in the lock bottom.Two kinds of the lock butt joint were analyzed by using ANSYS and limit analysis method,the limit loads for different structural dimensions were obtained,which were compared with design loads to get the strength margins under the conditions of different structures and different sizes.It was shown from the results that for two different lock-bottom welding structures,selection of flat head structure characteristic coefficient in accordance with GB 150-1998 and GB/T 150-2011 the results may be optimistic,or pessimistic to result in material waste.