Abstract
Circular-arch specimens were produced from aluminium rings. By using suitable rigid inserts in a ring, only a small portion of it was allowed to deform freely. The rings were subjected to uniformly-distributed, radially-inward-directed impulsive forces. The forces were generated by a high-energy electrical discharge through a single-turn coil which surrounded the ring. The induced currents in the ring were high enough to engender large, transient, radially-directed magnetomotive forces which caused gross plastic deformation. The elastic–plastic response of the arches was predicted by using a finite-difference numerical technique to solve the equations of motion. The analysis allows for circumferential and shear forces, as well as large changes in geometry. It also incorporates strain-hardening, but it ignores the influence of rotary inertia. High-speed photographs were used to record the transient shape of the collapsing arches. These were found to be in good agreement with the predicted profiles.
Get full access to this article
View all access options for this article.