Time Domain Analysis of Vibration Isolator Using Newmark Method Along with Newton Raphson Method

The vibration isolator plays a very crucial role in the mitigation of vibration and is used in a wide range of applications. In the present work, the sandwich circular panel along with the spring is considered as a vibration isolator. The sandwich circular panel comprises metal and viscoelastic material. The sandwich circular panel introduces passive damping in the system. The viscoelastic material used in the sandwich panel is modelled by the four-parameter fractional order derivative (FOD) material model. The non-linear FE model is developed to characterize the dynamic behaviour of the isolator based on the (FOD) constitutive relation. The non-linear FE model is coupled with the Newmark time integration method and then, solved by the Newton-Raphson method. In the present FE model, the tangent stiffness matrix includes the effect of anelastic strain history. The dynamic response of the vibration isolator is studied under the external harmonic force excitation. Also, the effect of varying thickness of the viscoelastic core on the performance of the isolator is analyzed.