Experimental, analytical, and numerical investigation of multi-chambered fluid-filled barrier for highway crash attenuators

Abstract

Guardrail end terminals and roadside crash cushions are common technologies deployed to absorb and redirect the energy of a colliding vehicle. The purpose of these devices is to reduce damage to structures and vehicles while limiting the effects these collisions have on motorists. The primary mode of energy absorption of these structures is through physical deformation. This physical deformation can often create hazardous scenarios for vehicle occupants. This paper shows the study of a new (patent pending) crash attenuator composed of a multi-chambered, fluid-filled barrier. Kinetic energy of the colliding vehicle is transferred to the fluid and through the internal structure. As fluid moves through the structure, energy is dissipated through viscous friction; therefore, reducing the peak forces experienced by the vehicle and its occupants and reducing damage to the structure and the vehicle. Experiments were conducted using a mechanical ram to impact a dual-chambered cylindrical plastic container partially filled with water. The impact event was recorded using a high-speed camera and the acceleration impulse was measured using an accelerometer attached to the ram. The results of this study show that the addition of interior chambers and fluid decreased the reaction forces by nearly 50% and a two-fold increase in energy absorbing efficiency as compared to an empty structure. Analytical and numerical approaches were used to assess the energy dissipation due to plastic deformation of the structure. The addition of fluid and internal chamber reduced the plastic deformation of the sample by 9.1% as compared to the empty structure. This confirms the ability of the present structure to maintain low reaction forces while reducing damage to the structure and in turn increasing barrier lifetime. The present barrier technology can potentially replace existing guardrail end terminal and crash cushion systems and due to its small footprint, can be utilized in areas where traditional systems cannot be deployed due to space constraints.