Quasi-static loading of piping welded joints

One of the main issues in relation to the pipe system design process is the analysis of the quality and strength of joints occurring in them. The analysis is necessary because of the possibility of a damage of these systems that could cause dangerous incidents in relation to the safety of people and the environment. The most common cause of this type of the danger is the sudden appear unexpected catastrophic or quasi-static loads. The paper presents a series of numerical and experimental tests of the impact of quasi-static loads on the character of deformations and the strength of the welded joint of pipes made of API 5LX80 material. In the first stage of the work, the strength analysis of the pipe without a weld joint and with a weld joint was performed using the finite element method (FEM). The purpose of this analysis was to identify the load causing the strain of the specimen to the strength limit of the material used. Based on the identified load, experimental tests were performed on a pipe specimen with a weld joint. Obtained results of numerical and experimental tests allowed determining the maximum load causing the strain of the material at which the weld joint is not damaged.