A study on the deformation and crushing of copper tubing: experiments, theory & FE modelling

A series of 250 mm lengths of copper tubing, of 15 mm outer diameter and 0.7 mm wall thickness, were studied to determine their deformation if they were pinched or crushed between rigid objects applying a given force, to replicate potential accidental damage suffered by the copper pipes during service. A finite element modelling framework was developed to simulate the crushing of a copper pipe the same dimensions as that used for experiments, and the experimental data allowed for a validation of the pipe crushing at approximately room temperature, to consider copper pipe carrying cold water. The FE modelling activity was then extended to consider the deformation of copper pipe at 80∘C, carrying heated water at this temperature. The modelling agreed reasonably well with experiment, and applied forces of 1.5 kN began to deform the cold pipe, with the pipe collapsing on itself at loads of 6 kN. The heated pipe began to deform at roughly 1.25 kN. Lastly, theoretical flow calculations were performed to determine the Reynolds value, the flow velocity and the pressure loss and head loss per unit length of the deformed pipes, according to classical pipe flow calculation methods.