An analytical model for effective mechanical properties of multi-phase composite conductor

摘要

Compact and lightweight electromagnetic machinery (EM) has been envisioned as a critical component in future combat vehicles and weaponries. One of the integral elements in the system is the electromagnetic composite conductor. Materials used in the conductor Consist of electrical conducting core and outside insulating layers (Figure 1). The metallic conductor core are wrapped with the insulating composites and packed into a winding assembly. Accurate mechanical properties of the conductor are essentially important because they provide the fundamental material parameters in the design and analysis of the EM system structural responses under the combined mechanical, electromagnetic, and thermal loading. Due to the anisotropy of the insulation layers and the structural heterogeneity, these constants are difficult to be measured accurately, especially transverse and shear properties, as well as the Poisson's ratios. This paper introduces an analytical modeling and numerical approach to quantitatively predict the effective mechanical constants of the conductor unit cell. The analytical model was developed based on a two-step homogenizations and mechanics analysis for composite unit cell which derives the effective properties of the out-wrapped composite insulation layers and the homogenized conductor mechanical properties. The procedures of using numerical approach and finite element method to determine the unit cell effective constants were also described and the results of the FEA prediction were presented. The analytical predictions were compared well to the numerical results for the nine material constants that characterize the effective mechanical properties of the composite conductor.