Specification of a Specimen for Accelerated Thermal Aging Tests

Abstract

This document presents design considerations of a sample for accelerated thermal aging tests. The proposed specimen is a parallel wired solenoid that is evaluated by using an axi-symmetric 2D finite element (FE) model in Comsol multi-physics. The aim of the design model is visualizing an interior stress distribution of an idealized coil in order to interpret the physics-of-failure in a more complex system than twisted pairs of enameled wires. Design-for-manufacture and design-for-testability aspects are considered when developing the reference FE model. Fault development is the main concern when analyzing electric field distribution across electric insulation system (EIS), and the related mechanical and thermal stresses under thermal loading conditions from deterioration of EIS to inter-turn short-circuit. The significance of this theoretical kind of preparatory study is to design a test that can facilitate recognition of a fault development and identification of related diagnostic indicators.