Mass-controlled contact variable stiffness elastic metamaterials for bandgap tuning

The tunability of elastic metamaterials has emerged as a focal point in recent years within the realm of metamaterial research. However, achieving extensive bandgap tuning at low frequencies and identifying appropriate control mechanisms remain challenging tasks in existing studies. In this research, we propose a novel approach based on mass-controlled contact-variable stiffness locally resonant elastic metamaterials. By altering the mass and orientation of oscillators, the contact state of the variable stiffness structure can be modified within the unit cell, resulting in significant variations in effective stiffness and enabling broad bandgap tuning at low frequencies. Furthermore, the gravitational field control method employed in this study offers simplicity, rapidity, and ease of manipulation. The materials utilized in this research are readily accessible, and the structure's simplicity facilitates ease of fabrication, thus holding promise for practical applications in scenarios such as vibration and noise reduction in ships, vehicles, buildings, and other related fields.