Predicting the Durability of Aircraft Electric Wires with Irradiated Polyolefin Insulation

The article presents a theoretical approach to calculating the durability of the BPDO type (where B stands for onboard, P for wire, and DO for insulation made of thermally stabilized cross-linked polyethylene and a protective layer of fluoroplastic) wires with irradiated polyolefin insulation, which are most widely used in aircraft applications. Earlier studies have shown that for low-voltage wires with a small thickness of insulation, its destruction is in most cases caused by gradual thermal oxidative destruction of the polymer. Therefore, by determining the induction period or an indicator associated with it through a correlation, it is possible to predict the cable product durability. A theoretical substantiation of the appearance of the structurally sensitive insulation parameter TIO, obtained as the temperature value at the intersection of the tangents to the base (baseline) and the left arm of the exothermic peak on the curve of thermal analysis of polyolefin insulation samples, is considered. Calculation formulas and kinetic parameters for aging of BPDO type onboard wires are proposed.