Random vibration of sandwich beam with a shear thickening fluid core

The dynamic performances of a sandwich beam with a shear thickening fluid (STF) core subjected to a random excitation are investigated. First, the STF is prepared and a new constitutive model is proposed based on the oscillatory rheological measurements. Next, a flexural vibration model of the sandwich beam with an STF core under random load is developed, and a parametric study is carried out. It is found that the response frequencies and damping ratios for the first three modes of the beam increase with the standard deviation of the external random excitation. The sandwich beam with STF provides better damping for larger broadband excitation. Additionally, the beam with an STF core will produce a response both inside and outside the load frequency domain. Furthermore, an optimal thickness ratio for the structure that maximizes the damping ratio of the structure is identified. It is important to note that this optimal thickness ratio of the structure varies with the order of vibration modes. This research provides valuable insights into the design of structures using STF and also contributes to the development of dynamic constitutive models for STF.