Design of metastructures with quasi-zero dynamic stiffness for vibration isolation

A metastructure consisting of numerous unit cells with quasi-zero stiffness property has been designed and researched in this paper. The quasi-zero stiffness property is realized in each unit cell by combining snap-through behavior of a sinusoidal beam and bending dominated support of two semicircular arches. Mechanical behavior of the metastructure is derived theoretically based on the property of all the unit cell components. The unit cell and metastructure samples are designed and fabricated by the FDM additive manufacturing technology. Experiments and simulations are carried out on the samples to investigate static characteristics of the metastructure and verify the theoretical solution. Based on that, dynamic analysis of the metastructure under displacement control vibration is carried out to study the vibration isolation performance of the metastructure by theoretical and simulation methods. Results show that the presented metastructure can achieve good quasi-zero stiffness property by designing the unit cells properly. It exhibits excellent vibration isolation performance and has great potential to be used as continuous structures or materials in the vibration isolation for small-scale equipment which is difficult to be realized by installation of the spring mechanism.