Finite element simulation of mechanical bump shock absorber for sled tests

It has been observed that during sled tests with hydraulic decelerators, a non-programmed deceleration is generated from the rod inertia. This behavior is observed during the first contact, when the platform impacts the decelerator. This non-programed deceleration usually influences the development of the test, as it modifies the deceleration pulse, reaching levels high enough to activate the airbag pyrotechnics. To overcome the rod’s inertia it is common practice to use a hydraulic bump shock absorber. This absorber employs hydraulic fluid or air to dissipate the kinetic energy. This study, proposes using an alternative mechanical bump shock absorber, in which the kinetic energy is transformed to deformation energy through the plastic deformation of an aluminum honeycomb panel. While for the hydraulic bump shock absorber it is necessary to perform tests to adjust the absorbed energy, in the proposed mechanical bump shock absorber the absorbed energy is estimated through a nonlinear finite element simulation using Abaqus Explicit V6.8–2. Therefore, this non-conventional mechanical bump shock absorber can be used to minimize the effect of the rod’s inertia on the deceleration pulse.