Theoretical aspects of thermomechanical forces in power cables

A theoretical treatment of the mechanical forces developed in power cable conductors as a result of temperature changes is presented, using equations based upon classical beam theory. From considerations of flexural rigidity, it is shown that, in most practical cases, such conductors should have very little bending stiffness and possess considerable longitudinal stiffness. It is also proposed that a joint may be effectively represented as a very stiff spring. For single-core cables, the theory is in good agreement with previously published work, under most practical conditions. A brief extension of the analysis to cover the mechanical behaviour of multicore cables is given.