DYNA3D Simulations of Pendulum Impact Tests on Steel Guardrails

The response of a G4(1S) strong post steel w-beam guardrail system to dynamic impact has been investigated in a series of full-size physical tests and in simulated experiments using LLNL-DYNA3D. The physical tests were conducted at the Federal Outdoor Impact Laboratory (FOIL) at the Turner Fairbank Highway Research Center of the Federal Highway Administration (FHWA) in McLean, Virginia using a pendulum. In the pendulum tests, an 880 kg mass was used to strike the rail perpendicular to its face. The rail section was attached to steel posts and blockouts and supported in a specially designed fixture. Initial velocities of the pendulum at impact were 9.25, 20, 30 and 35 km/h. From acceleration data taken during the testing, acceleration, force, velocity and displacement histories of the impact event were calculated. Data from the LLNL-DYNA3D simulations of the impact tests compared well with the data obtained from the full-scale testing. Animations of the deformed shapes of the rails at 25 msec intervals compared favorably with high speed film images. Force versus displacement histories showed good agreement with those obtained from quasi-static experiments.