Energy Absorption in a 1D Array of Axially Aligned Pendulums With Linear Torsional Coupling

This paper evaluates wave propagation and energy absorption in a 1D array of axially aligned pendulums under various forms of base excitation. In the system studied, each pair of pendulums comprising a single unit cell is connected through linear torsional coupling, and asymmetry is introduced by varying their masses. Similar to translational systems, when subjected to harmonic base excitation, band gaps are observed in this rotational system over predictable frequency ranges. It is observed that varying the uncoupled restoring force parameters (mass and gravitational strength) shifts the expected band gap regions under harmonic excitation. This asymmetry in pendulum masses can also be exploited for the purposes of energy absorption when the system is subjected to base excitation in the form of an impulse. Numerical simulations are performed to demonstrate the accuracy of analytical solutions for both types of external forcing.