Stress-Strain Simulation of Viscoelastic Model of Sealing Disc Material for In-Pipe Detector

Abstract In the pipeline inspection industry, polyurethane materials are chosen as the material for sealing discs in pipeline inspection detectors due to their excellent oil resistance, chemical stability, and mechanical stability. However, polyurethane materials are highly prone to generating interface frictional heat and adhesive wear during operation, presenting challenges in signal acquisition and detection. The simulation of frictional heat and adhesive wear necessitates the utilization of a viscoelastic model. Currently, the mechanical performance simulation of polyurethane materials often employs hyperelastic models, such as the Mooney-Rivlin model, which neglects the mechanical hysteresis losses induced by viscosity. This not only hampers the accurate evaluation of the sealing disc’s mechanical performance but also precludes the description of the generation of frictional heat and wear. In this study, compressive stress-strain tests and compression relaxation tests carried out on polyurethane materials. The generalized Maxwell model representing the viscoelasticity and the Mooney-Rivlin model representing the hyperelasticity were obtained. The Abaqus software’s “dynamic, explicit dynamics module” was employed to calculate the stress-strain distribution over time for the two models under different pressures. The models were constructed for polyurethane annular materials and steel annular materials using a face-to-face contact form, with a load range of 0.1 MPa to 0.5 MPa. In comparison with the hyperelastic model, differences in the stress-strain relationship over time were observed between the two models. Moreover, the material’s strain was found to be correlated with the change in stress. The viscoelastic model can provide a more accurate description of the material’s mechanical performance, with differences primarily manifested in the phase lag effect of the angle. This research opens up a new research direction for establishing a viscoelastic mechanical model for sealing discs in pipeline inspection detectors, enabling the possibility of studying the dynamic face-to-face friction model of viscoelastic materials (including frictional heat simulation and wear distribution calculations) through simulation calculations.