Strength of Materials, Vol. 41, No. 2, 2009

STRENGTH ANALYSIS OF A SPLIT SLEEVE IN A PIPE CONTAINING A DEFECT I. V. Orynyak,a S. A. Okhrimchuk,b L. I. Venglovskii,c V. A. Strizhalo,a S. M. Ageev, S. P. Chuikov, É. V. Chechin, and A. V. Bogdan a d a a

UDC 539.4

We study the decrease in the strength of a pipe containing an artificial defect. On the basis of the analytic and numerical models, we consider the influence of the structural features of a split sleeve on its load-carrying ability. We also analyze the joint operation of a sleeve and a pipe containing an artificially made axial surface defect. The results of the numerical analysis are compared with the experimental data. Keywords: split sleeve, pipe, defect, residual strength. Introduction. The problem of aging and exhausting the service life of pipelines is connected, first of all, with the appearance of various types of defects in the material and changes in the shape of the pipe. If the operator makes a decision that the strength of the pipe containing a defect is insufficient, then it is necessary to apply certain improving measures. Note that the reinforcement of pipes by welded sleeves is the most widespread procedure of this sort. However, for the underwater pipelines, a more acceptable method of maintenance is to use split sleeves that can be mounted by divers relatively easily. We can conventionally split these sleeves into two groups: hermetically sealed sleeves and sleeves with partially recoverable load-carrying ability (SPRLCA). The sleeves from the first group must withstand the nominal internal pressure with the same safety margins as the main pipe. The sleeves from the second group are characterized by a limited load-carrying ability. Therefore, in the case of their application, it is necessary to take into account the joint operation of the defective pipe and the sleeve. It is worth noting that the available literature contains no theoretical data on the joint operation of defective