Experimental Examination of Theory of CTE (Coefficient of Thermal Expansion) Control Technology

Abstract

A previously proposed lamination tailoring technique for precise control of a coefficient of thermal expansion (CTE) under a wide range of temperature is examined by detailed measurements of a CTE of two types of specimens : rectangular plates and tubes of carbon/epoxy composite. The theoretical basis of the technique consists of two concepts of the thermoelastic invariants and the lamination parameters. Experiments for verification are conducted with a specially designed measurement system. The results of 40% 0°and 60% ±45°plates fall between ±1×10^-7°C^-1 within the temperature range from -50°C to 40°C. Quite similar results are obtained for tubular specimens. It is also uncovered that the axial CTE is susceptible to variation of an off-axis angle. Precise control of the angle is a key point of the present technology .