Fatigue life extension in wide-band region of pipes by an inertial damper

The pipe conveying fluid, typically subjected to wide-band excitation, is susceptible to multi-modal resonance, which can result in structural fatigue and failure. The inertial damper, characterized by its flat potential well, demonstrates the capability to suppress vibrations adaptively across a broad frequency range. Consequently, this paper aims to investigate the application of the inertial damper to enhance the fatigue life of the pipe within the wide-band region. The inertial damper is fabricated from visco-hyperelastic materials, and its damping characteristics are determined by the constitutive relationship of these materials. Furthermore, the governing equation for the bending vibration of the pipe system is derived based on Newton’s second law. The response of the pipe is solved using the harmonic balance method and validated through the Runge-Kutta method. Subsequently, the influence of visco-hyperelastic parameters on fatigue life is thoroughly examined and discussed. Results indicate that the inertial damper significantly improves the safety performance of the pipe. Fatigue life prediction based on the Paris theory shows that the inertial damper enhances the fatigue life of the pipe system by mitigating stress during resonance, thereby improving the reliability and durability of the pipe system. The proposed inertial damper offers a simple structural design and theoretical foundation for controlling wide-band fatigue damage in pipes.