Compressive testing of reinforced Nomex honeycomb at elevated temperatures

Abstract

The effect of varying temperature on the compressive properties of a Nomex honeycomb core reinforced with small diameter composite tubes and rods has been investigated experimentally. Compression tests have been undertaken on a commercially-available Nomex core reinforced with tubes or rods at temperatures between 20 and 140 °C. Tests were also undertaken on unreinforced Nomex cores in order to assess the benefits associated with localized reinforcement of the core. Compression tests on the unreinforced cores have shown that the strength decreased steadily with increasing temperature, passing from 4.8 MPa at room temperature to 3.8 MPa at 140 °C. Similarly, the specific energy absorption (SEA) of the plain core samples decreased slightly from 22.3 to 18.9 kJ/kg over this range of temperatures. Reinforcing the cores with either rods or tubes had a positive effect on the compressive properties of the cores over the range of temperatures considered. For example, the room temperature compression strengths of the rod reinforced cores were 70% higher those of the plain core. Similarly, at 140°C, the rod-reinforced systems were 20% stronger than the plain core. Finally, the energy-absorbing capacity of the tube reinforced cores was higher than that of the rod-reinforced cores.