Application of New Concrete Model to Roadside Safety Barriers

The subject of roadside safety has been seeing a healthy growth in the use of nonlinear finite element analysis in designing and analyzing roadside hardware systems. Some factors that helped researchers include the expanded capabilities of LS-DYNA commercial finite element code, the availability of several public domain vehicle models and the availability of material models explicitly built and modified for roadside safety applications. One of these new material models is *MAT_CSCM (and the short input version *MAT_CSCM_CONCRETE) incorporated in LS- DYNA version 971 as material type 159. Material model *MAT_CSCM which was developed by APTEK INC. is a continuous surface cap material model with the ability of capturing concrete material behavior using minimal input like the compressive strength of concrete and maximum aggregate size. In this paper two examples of using LS- DYNA to simulate impacts with concrete barrier are presented. They are two different pendulum simulations of a concrete parapet with a steel railing on top. The deformation and damage profiles along with the force time history were used as measures for comparing tests and simulations. Both examples indicate a reasonable correlation between tests and simulations. Figure 1a shows the response of the concrete parapet as tested and figure 1b shows the response calculated from the LS-DYNA simulation.