承载能力可调力电耦合曲梁准零刚度隔振器设计与分析

To address the challenge of limited adaptability to varying loads in existing quasi-zero-stiffness isolators, this study designed a load-adjustable piezoelectric quasi-zero-stiffness isolator. This isolator primarily comprised a piezoelectric patch with an externally connected negative capacitance shunt circuit and a cosine-shaped curved beam. The nonlinear stiffness of the curved beam could be adjusted, by modifying the negative capacitance value, allowing for control over the isolator’s load-bearing capacity. Initially, by adopting modal superposition and minimum total potential energy principle, the force-displacement relationship of the piezoelectric curved beam was derived. The derived relationship accuracy was validated through comparison with finite element results. Subsequently, the piezoelectric curved beam was coupled with a U-shaped stiffer wall to form the isolator. Both the simplified analytical model and the comprehensive finite element model of the isolat- or were established to investigate its isolation characteristics under various loads. The results indicate that the regulation of the modulus of piezoelectric materials through negative capacitance circuits can generate the quasi-zero-stiffness characteristics under different loads, achieving excellent low-frequency vibration isolation performance.