A numerical methodology for lifetime estimation of HDPE pressure pipes

Using linear elastic fracture mechanics a new methodology for a lifetime assessment of internally pressurized polymer pipes was developed. The concept is based on the numerical calculation of stress intensity factors for pipes under different loading conditions in combination with experimentally determined creep crack growth kinetics. Comparison of simulated lifetimes with experimental data from tests of internally pressurized pipes proved the principal applicability of the concept suggested. Major parameters affecting the pipe lifetime are identified and discussed. Combination of the creep crack growth tests and numerical simulations can be a very powerful tool for lifetime estimation of plastic pipes under different loading conditions.

► Damage of the HDPE pipes caused by slow crack growth was numerically studied.
► A special algorithm, which optimized the crack front shape, was developed.
► General equations for an estimation of the stress intensity factor were presented.
► Essential parameters affecting the simulated lifetimes were identified and discussed.