Non-linear energy absorbing column assembly

Abstract

A non-linear energy-absorbing column assembly has tunable force gradient which enables a non-linear collapse response under rapid dynamic loading. The column assembly includes the cooperating components of an outer sleeve, an inner tube, and a bearing sleeve, the inner tube received within the bearing sleeve, and the bearing sleeve received within the outer sleeve. Radially spaced serrations are made in an insert end of the inner tube to form one or more deflection tabs at an end of the inner tube. The bearing sleeve holds one or more spherical elements in contact with one or more deflection tabs of the inner tube, and in contact with an interior surface of the outer sleeve. Variable deflection of the deflection tabs in response to the changing location of the spherical elements on the deflection tabs produces a non-linear collapse response under an axial load applied to the assembly, which eliminates peak load spikes or other abrupt linear transition from initial loading to a substantially constant collapse mode. Variable arrangements of spherical elements in the bearing sleeve are also described and claimed.

Dependencies are inferred from the claim text.