Why don't you cover plastic design considerations in your standards?


The short answer to this question is that, in general, engineered wood products and assemblies do not exhibit well-defined plastic characteristics. While some material properties show nonlinear stress-strain behavior (e.g., compression perpendicular to grain) as do many types of dowel-type wood connections, they do not exhibit the extended plastic region exhibited by mild steel. Neither do engineered wood products generally exhibit "transition" failure modes such as those of reinforced concrete (i.e., concrete cracking, load redistribution, etc.). As new engineered wood and non-wood composite products are developed and marketed that DO exhibit well-defined plastic characteristics, we hope to extend some of the classical plastic analysis techniques to these products in our LRFD documents.