厚壁套管等效外挤载荷计算

The calculation of the equivalent external collapse load of thick-wall casing

鉴于ISO 10400新标准提出的计算厚壁套管抗挤强度公式是针对均匀外挤载荷的,不适应非均匀外挤载荷下套管抗挤强度计算的状况,根据虚功原理和Mises屈服准则,提出了2种计算等效外挤载荷的方法。将作用在套管上的非均匀载荷转化成与之具有相同破坏能力的均匀载荷。算例分析表明,2种方法计算的等效外挤载荷具有较好的一致性,基于新标准的挤毁理论,套管在非均匀载荷条件下的抗挤强度也有较大的提高。

The formula proposed by the ISO 10400 new standard to calculate the collapse strength of thick-wall casing is applied to even external collapse load. It is not suitable for the calculation of collapse strength of casing under uneven collapse load.According to the virtual work principle and the Mises yield principle, two methods to calculate equivalent collapse load were put forward. The uneven load on the casing was converted to the even load which had the same damage capacity. The example analysis shows that the equivalent collapse load calculated by the two methods is of desirable consistency. According to the new standard-based collapse theory, the collapse strength of casing under uneven load increases remarkably.