Numerical Investigation of Wave-Induced Damping and Dynamic Response of Artificial Mangrove Roots

Abstract Coastal erosion and wave impact create significant challenges for shoreline resilience, and nature-inspired solutions like artificial mangrove roots (AMR) could help address these challenges. While natural mangroves are known for their wave-damping abilities, there is a lack of detailed numerical studies. This study conducts a numerical investigation into the wave-induced damping capabilities of AMR structures designed to imitate the complex morphology of natural mangroves. Such nature-inspired AMR structures are modelled in OrcaFlex, the dynamic multibody analysis software, to simulate multi-body responses by considering regular waves. The numerical model incorporates detailed representations of main trunks and multiple root systems. Main trunk and parabolic shapes of the roots are modelled as rigid/flexible lines. Dynamic simulation results for different wave conditions and water depths are calibrated against experimental results in the literature. Wave damping coefficients are analytically estimated by utilising force coefficients from the dynamic simulations. Results indicate that AMR can significantly reduce wave energy, with sensitivity studies analysing the effects of wave-mangroves flexibility on the wave damping performance, wave-induced force and maximum bending stress. The present study demonstrates that numerical modelling offers a cost-effective alternative to experimental methods, reducing the need for extensive physical testing while still providing reliable predictions of wave damping and dynamic response behaviour. The findings contribute to the understanding of AMR responses to be considered potential as an effective coastal protection measure and provide insights for optimising AMR design for enhanced wave attenuations.