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Description
Vibrational fatigue is a leading cause of pipeline failure in industrial facilities, yet accurately predicting it remains a significant engineering challenge due to the complex interplay among structural dynamics, fluid-induced loading, and geometric nonlinearities. This work presents a numerical procedure to estimate the vibrational fatigue of piping systems subjected to dynamic excitation in industrial environments.The mathematical model discretizes each pipeline element as a three-dimensional Timoshenko beam, accounting for bending, shear, and torsional deformation, including inertia effects, all of which are critical in thick-walled or short-span pipe configurations where the classical Euler–Bernoulli assumptions introduce non-negligible errors. A key feature of the present approach consists of the presence of a deformed prestress equilibrium configuration at steady state due to the internal hydrodynamic pressure. The inner pipelining pressure and the magnitude of the pipe radial deformation are computed through an asymptotic one-dimensional hydrodynamic model based on the assumption of the flow of an incompressible viscous fluid and serve as input data for the subsequent time-harmonic dynamic response evaluation, enabling accurate capture of the pressure-stiffening effect on the natural frequencies and mode shapes of the system.Fatigue damage accumulation is estimated by combining the dynamic stress response, obtained via modal superposition, with an appropriate cycle-counting method and available S-N curve data at the pipeline joints. The tool is validated against both analytical benchmarks and experimental measurements reported in the literature, demonstrating reliable accuracy across representative pipe geometries and loading conditions.