Flow-driven flexo–piezomagnetic coupling in fluid-conveying structures

The present study investigates the flow-induced flexomagnetic coupling in fluid-conveying structures subjected to an external magnetic field. A stability analysis is conducted to reveal the stability boundaries and nonlinear responses by considering several key parameters, including the flexomagnetic coupling parameter γf, the magnetoelastic coupling number Mn, and the magneto-mechanical forcing parameter Fmn, in the presence of internal fluid flow. The results show that internal fluid flow enables a higher-order magneto-mechanical feedback loop, which delays the onset of Hamiltonian–Hopf bifurcation and flutter instability. Additionally, by increasing fluid flow velocity, a transition to highly nonlinear responses occurs due to broadband spectral amplification, and stronger modal coupling results from the fluid–structure interaction effect. Moreover, an additional restoring effect of flexomagnetic coupling exists, which limits excessive frequency amplification. Finally, the stability analysis reveals that while flow velocity and magneto-mechanical forcing parameter control the energy and load input to the system, the flexomagnetic effects regulate the redistribution and stabilization of that energy, governing the jump phenomena and hysteresis observed in the system's post-instability behavior.