Mechanical systems may experience time-varying factors during their actual operation. In engineering, the mass of a rocket will decrease monotonically along with fuel consumption during the powered-flight phase. It will also lead to the modification of the rocket’s stiffness. Likewise, the ambient atmosphere density and temperature change over time. Another example is a manipulator arm system. The moment of inertia on each joint is a complex time-varying function related to different working conditions.

Time-varying factors will influence the dynamical behaviour of the system. This can create problems in vibration control. Vibration analysis may feed more into the underlying behaviour of time-varying systems. It can also create solutions and proper system design. It plays an important role in modern and innovative engineering technology development. Meanwhile, the vibration control of time-varying systems requires intelligent actuators and control strategies.

The aim of this Special Issue is to bring together original research articles and review articles in vibration analysis and control. the dynamical behaviour of mechanical systems suffering from time-varying factors. Submissions about advances, the current state of vibration analysis, and control of time-varying systems are welcome. Research on theories, computation, devices, experiments and engineering applications are all welcome. We hope that this Special Issue will create an academic discussion in the field.

Potential topics include but are not limited to the following:

• Advanced modelling theory and technology for time-varying systems
• Parametric model reduction for time-varying systems
• Efficient numerical algorithms for time-varying system vibration analysis
• Sensitivity analysis and design optimization methods for time-varying systems
• Advanced control devices for time-varying systems
• Active and semi-active vibration control strategies for time-varying systems
• Applications to launching systems (e.g., air vehicles, ground vehicles, turbomachines, robotics), aero- and astronautics engineering, marine, transportation engineering and civil engineering)