Temperature Dependence of Young's Modulus and Internal Friction of Lucite and Karolith

Abstract

The Young's modulus and specific energy loss of Lucite and Karolith were measured at different frequencies in the neighborhood of 50 kc/sec. as a function of temperature. The temperature range for Lucite was from −55°C to 65°C, and for Karolith, 25°C to 110°C. It was found that the reciprocal of Young's modulus versus temperature curves showed positive curvatures at higher temperatures for both materials. At room temperature the Young's moduli of Lucite and Karolith were 4.72 and 6.14×10¹⁰ dynes/cm², respectively. The specific loss was found to vary with frequency for both materials and varied in a linear fashion for Lucite at room temperature. Absorbed water seemed to have a pronounced effect on the Young's modulus of Karolith.