Analysis of crack propagation and local strain of polyethylene pipes
Polimery 2013, No 1, 51
The influence of surface and inner longitudinal defects (rifts) in the pipes made from polyethylene, used in the construction of gas and water pipelines, on the possibility of rapid crack propagation (RCP) as well as on the increase of local strain at the front of the rift was analyzed. The value of stress intensity factor was calculated for the assumed rift dimensions and compared to its critical value for the material of pipe — changing as a result of the creep. On this basis the critical dimensions of rifts in regard to cracking were determined. Also, the value of tensile stress concentration at the front of the rift was determined as well as the increase in local strain as a result of material creep.