Effect of Spring Connection Position on an Acoustic-Black-Hole Double-Beam System for Vibration Suppression and Piezoelectric Energy Harvesting

This study proposes a spring-coupled acoustic-black-hole (ABH) double-beam system for simultaneous vibration suppression and piezoelectric energy harvesting. A fixedfree main beam is connected to an ABH absorber beam through a spring, and a piezoelectric patch is attached near the ABH cavity region to convert localized vibration energy into electrical output. The nonlinear governing equation of the main beam is derived using EulerBernoulli beam theory with geometric nonlinearity and the shortening effect. The method of multiple scales and the fourth-order RungeKutta method are used to analyze and verify the nonlinear dynamic response. The ABH absorber beam, piezoelectric coupling equation, and finite element model are further established to evaluate the effects of the spring connection position, X s , and the force application position, f. The results show that vibration energy can be transferred from the main beam to the ABH absorber beam and concentrated near the ABH cavity region. The maximum displacement reduction reaches 34.9% under the tested configurations. The best energy harvesting performance occurs when both the spring connection and excitation are located near the free end. For the configuration with X s = 3/4 and f = 3/4, where the spring connection and force application positions are both located at three-quarters of the main beam length from the fixed end, the theoretical, ANSYS-simulated, and experimental voltages are 3.35 V, 3.23 V, and 3.12 V, respectively. The voltage errors are within 1.59%−6.96% between theory and simulation and within 4.42%−11.28% between theory and experiment. These results demonstrate that the proposed ABH double-beam system can effectively reduce structural vibration while harvesting part of the localized vibration energy, showing potential for passive vibration control, smart structures, structural health monitoring, and low-power sensing applications.