Evaluation of Fracture Behavior for Pressurized T-Pipe by Finite Element Analysis

Abstract

T-pipe is one of the typical structural elements of LWR piping as well as T-joint. In the present situation, the evaluation of wall thinning for T-pipe is accomplished by assuring the sufficient strength around the opening area by using the design and construction code. This evaluation often assumes the replacement of a local wall thinning with a global wall thinning, which leads to excessively conservative prediction of burst pressures. In this study, three-dimensional finite element analysis was conducted to simulate the fracture behavior of a pressurized T-pipe test. The accuracy of the predicted burst pressures and appropriate modeling of the welded joint at the junction of the main and branch pipes were investigated. It was found that the burst pressure could be adequately predicted by applying a proper fracture criterion.

The Proposal of Wall Thickness Management Criteria of T-Pipes

“…This project performed burst experimental tests for T-joints (Tees) mock-ups [1] , FE analyses for the T-joints mock-ups [2] , evaluation of external pressure for T-joints [3] and developed a guideline for management of wall thinning of tees [4] . Also this project studied T-pipes (welding Tbranch connection) by an experimental mock-up test and FE analysis [5] and the management of wall thinning of the T-pipes (branch connection).…”

Pressure Tests for Thickness Management of Wall Thinning Tees

“…This project performed burst experimental tests for T-joint mock-ups (this paper), FE analyses for the T-joint mock-ups [1], evaluation of external pressure for T-joints [2] and developed a guideline for management of wall thinning of T-joints [3]. Also this project studied T-pipes (welding T-branch connections) by a experimental mock-up test and FE analysis [4] and the management of wall thinning of the T-pipes [5].…”