부산대학교 도서관

A physical and mathematical model for predicting the workability of an electrically conductive sphere valve under short-term induction heating by an unstable electromagnetic field is proposed. Initial relations of centrally symmetric problem of thermomechanics for a solid electrically conductive sphere are obtained. Azimuthal component of the magnetic field strength vector, temperature, and radial component of the displacement vector were chosen as determining functions. The change in time of azimuthal component of stress tensor and intensity of stresses in the sphere depending on the amplitude-frequency characteristics of unstable electromagnetic action and time of its duration is numerically analyzed. Limit values of amplitude-frequency characteristics of unsteady electromagnetic action and time of its duration at which the considered sphere loses operability as a constructive element are established.