Assessment of the Effect of Design Parameters of Pressurized Sand Dampers from Component Testing

Abstract

This study presents results from cyclic testing on various configurations of a recently developed pressurized sand damper in which a steel sphere is moving within a cylindrical tube filled with sand that is under pressure. The experimental campaign investigated the effects of the key design parameters of the damper, namely, the effect of the clearance between the moving sphere and the cylindrical tube and the effect of the overall length of the damper to its force output. The recorded force–displacement loops when normalized to the strength of the pressurized sand damper reveal remarkable order with stable behavior and confirm that the force output is nearly rate-independent. The paper also presents recorded force–displacement loops where the sphere mounted on the piston rod is replaced with a bolt where only the bolt head and nut are protruding from the moving piston rod. With this configuration, the pinching behavior of the pressurized sand damper at longer strokes is suppressed without generating large forces at longer strokes.