Longitudinal wave characteristics of magnetic field sensitive viscoelastic polymeric rods

Engineers frequently encounter structural elements which made of polymeric viscoelastic materials in various industrial applications. Studies of impact and fracture under high strain rates and characterization of the dynamic behavior of viscoelastic materials are some them. In this thesis, longitudinal wave characteristics of magnetic field sensitive viscoelastic rods under transverse magnetic field effect is studied by including lateral inertia effect. The analysis is based on Love rod theory. The material of viscoelastic rod is selected as epoxy. The polymeric rod is modelled as a standard linear solid viscoelastic material. This simple viscoelastic model used here is represented by elastic spring connected in parallel with a Maxwell element. A new wave equation was derived for longitudinal waves in viscoelastic rods that incorporate the effect of lateral inertia. The obtained results are compared with one dimensional analysis results. This study reveals the wave and attenuation characteristics of the magneto-sensitive polymeric rods depending on the diameter values, under the transverse magnetic field effect. The comparative results of the analysis show that transverse magnetic field has a remarkable effect on the wave phase velocity and attenuation coefficient. The transverse magnetic field leads to a significant reduction on attenuation coefficient, especially for high frequency values and large diameters. It can be said that the lateral inertia effect becomes negligible in the larger frequency range with increasing the magnetic field intensity. The obtained explicit solution is illustrated graphically. The theoretical progress curves of the wave velocities and attenuation coefficients presented in this analysis show quite agreement with the many experimental results given in the previous literature. The determination of dynamic behaviour and the wave propagation coefficients of the viscoelastic materials are often done with the Split Hopkinson Pressure Bar (SHPB) experimental apparatus. In these experiments the frequencies of the signals are low. Hence analysis results obtained for Low frequency ranges can provide a reliable data for the similar experimental studies in related the magnetic field effects.