Analysis of Low Temperature Anti-Cracking Property of Epoxy Materials for Cable Intermediate Joints

Abstract

Abstract In this paper, multi-channel strain sensors are used to in-situ monitor the changes of strain with temperature under low temperatures for different stress angles in epoxy cladded metal inserts and the low temperature anti-cracking performances of the epoxy materials used for cable intermediate joint were analyzed. Compared with the foreign epoxy EP-0, the self-prepared toughed epoxy EP-1 has higher tensile strength, larger elongation at break and smaller modulus, showing a stronger toughness. The glass transition temperature of EP-0 and EP-1 epoxy materials are approximately the same. Besides, although the epoxy cladded metal inserts for EP-0 and EP-1 were both uncracked and intact when the temperature decreased from 0 to -70 °C, the strain and the stress at the stress angle R2 of EP-0 increased more rapidly with the decrease of the temperature than that of EP-1, which can be inferred that the cracking temperature of EP-0 is lower than that of EP-1. Thus, the low-temperature anti-cracking performance of self-made toughed epoxy material is better than that of commonly used foreign epoxy material.