Model-Based Optimization of Coupled Thermo-Electro-Magneto-Mechanical Behavior of Load-Bearing Antennas

Abstract

Load-bearing antennas are multi-functional sensing (actuating) and receiving (detecting) devices that are integrated with a load-bearing structure. These antennas are appealing for military applications, importantly Unmanned Aerial Vehicles (UAV). The antenna structure is subjected to mechanical forces, temperature gradients, and electromagnetic fields, giving rise to highly-coupled nonlinear thermo-electro-magneto-mechanical (TEMM) behavior. In the present work, we have developed analytical techniques and computational tools for multi-scale, multi-physics modeling of composite load-bearing antennas, specific to UAV applications. Our mathematical model, based predominantly on first principles, employs the thermomechanical governing equations (i.e., conservation of mass, momentum, angular momentum, energy and second law of thermodynamics) coupled with Maxwells equations. The macro-scale coupling terms that characterize the thermo-mechanical and electromagnetic interactions are deduced from micro-scale behavior. Our modeling has identified 92 nondimensional numbers which quantify the competition between physical effects in the operation of load-bearing antenna. Depending on the design of the structure and nature of the excitation, only a subset of physical effects are dominant, which dictates the appropriate computational model. A fixed relative ordering of all competing effects as quantified by nondimensional numbers, determines a regime of antenna/environment interaction. The mathematical structure of leading-order equations for various physical regimes is presented for use in the optimization and analysis of coupled TEMM behavior of load-bearing antennas.