一次应力计二次应力壁厚的选取问题? 管线壁厚有理论壁厚so(根据压力,由强度公式计算得出)、公称壁厚sn(理论壁厚加上总腐蚀余量向上圆整)。总腐蚀余量 c’ 又由三部分组成:腐蚀余量c1、螺纹或凹槽深度c2、厚度负偏差c3 那么,(1)计算一次应力时(由持续载荷引起的),壁厚应该剔除腐蚀余量,是用的理论壁厚so吗?还是用的so+c2+c3 ? section moduli used to compute the stresses in this paragraph shall be based on nominal pipe dimensions less allowances , i.e., the sum of mechanical (thread or groove depth), internal and external corrosion, and erosion allowances. areas used to compute the stresses in this paragraph assume nominal pipe dimensions less allowances affecting the inside diameter of the pipe, i.e., the sum of mechanical and internal corrosion and erosion allowances. 按照asme b31.3 2012描述计算一次应力时候选用的横截面积是最小的,是需要减去相关的余量。 ( w4 t1 k1 j$ l% u: a6 r7 l# b (2)计算二次应力时,壁厚是用的公称壁厚sn 吗? - v8 《asme b31.3 》319.3.5 dimensions. nominal thicknesses and outside diameters of pipe and fittings shall be used in flexibility calculations . d 公称壁厚计算二次应力没错 m: ~5 s1 a# q (3)另有,caesar中,wt/sch对应的是公称壁厚sn 吗? 管子标号对应的是公称壁厚的厚度,这个厚度是从计算厚度加上余量腐蚀等等后圆整到规范壁厚的壁厚。 查看更多