Date of this Version
Report # MATC-UNL: 220
An improved LS-DYNA model of ¾-in. (19-mm) diameter 3x7 wire rope commonly used in roadside cable guardrail installations has been developed. A Belytschko-Schwer beam element was selected along with material *MAT_166. Numerical noise was reduced using part stiffness damping with a coefficient of 2%, and frequency range damping with a coefficient of 12%. The optimum element length based on timestep, accuracy, and computational cost was determined to be between 0.4 and 0.8 in. (10-20 mm). Dynamic component tests were conducted on wire rope to determine material properties. These tests were simulated and the results compared to the physical tests. The new proposed wire rope model more accurately simulated the wire rope tension and bogie vehicle motion than other previously-developed wire rope models. The wire rope was also modeled in full-scale crash test models using a Chevrolet C2500 pickup model, consistent with NCHRP Report No. 350 TL-3 impact conditions. Results of the crash test and simulation were compared, and the wire rope response was determined to be accurate. Therefore the new wire rope model was determined to be an improvement over existing models of wire rope and is recommended for use in cable guardrail simulations.