Quasi-zero-stiffness vibration isolation: Designs, improvements and applications

Most of the engineering vibrations are harmful, due to many unfavorable consequences caused by them, such as structural damage, poor working accuracy, etc., making it necessary to implement vibration isolation measures. Traditional linear vibration isolation methods have significant deficiencies regarding isolating low-frequency vibrations, in which the stiffness of the isolation system becomes a dominant factor. The quasi-zero-stiffness (QZS) vibration isolation technology, developed in recent decades, can greatly reduce the dynamic stiffness without reducing the static stiffness and thus extend the vibration isolation frequency band to low frequency region. A variety of approaches for constructing QZS isolators have been proposed based on geometric nonlinearity, magnetic nonlinearity, deformable components and so on. With higher demands and more complex operating conditions, many improvement strategies have been proposed to further enhance the overall performance of QZS isolators from various aspects. To date, a small portion of theoretical achievements in QZS vibration isolation have been applied in engineering fields, showing great advantages over linear vibration isolation methods. In these contexts, a comprehensive review of the QZS vibration isolation technology is essential. This paper is devoted to summarize the main research progress of QZS vibration isolation in terms of designs, improvement strategies and applications, to provide a general overview of the QZS vibration isolation technology for researchers in related fields.