Generalised scaling relations for dynamic centrifuge tests

The trend toward physical modelling of larger prototypes triggers a move towards expansion of the current capability of dynamic centrifuge tests. In this paper a method based on the concept of two-stage scaling is proposed that allows expanded use of the currently available facilities. In the first stage a prototype is scaled down into an intermediate virtual model based on the scaling relations in a 1g field with a scaling factor of μ (prototype/virtual model). In the second stage this model is scaled down into a physical model using the conventional scaling relations in the centrifugal field with a scaling factor of η (virtual model/physical model). In this manner, a large scaling factor λ = μη (prototype/physical model) can be broken down into the smaller scaling factors μ and η, and thus the centrifuge model tests can be performed with the smaller scaling factor η. In effect, the limits in the scaling factor for the currently available centrifuge facilities can be expanded by a factor of μ. Validation of the proposed method is provided by algebraic derivations based on the mechanics of model tests.