Optimal Material Model for Analysis of Wood Guardrail

Abstract

The overall performance of guardrail systems is mostly dependent on the strength of the wood posts. Therefore, developing an accurate model of wood post components of guardrail systems is essential. Wood posts are among the most common materials currently used in highway construction. Accurately simulating the breakaway characteristics of wood material posts is necessary for design. In this study, different material models are evaluated to determine their accuracy of representing the wood post behavior including, the failure behaviors of southern yellow pine wood. The material models are evaluated for a controlled release terminal (CRT) post and a standard guardrail post being impacted by a pendulum. Finite-element software LS-Dyna is one method that can be used to analyze the failure behavior. A description is provided of the development of the material models for the CRT and standard wood post. The simulation results are compared with data from tests performed by Texas A&M Transportation Institute (TTI) to find the material model which best matches the experimental data. The accuracy of the results was based on a qualitative comparison. This research shows that material model - 143 wood pine responded with more accuracy compared to the other material models.