Modeling Vertically Mechanically Laminated Lumber

Abstract

A nonlinear, two‐dimensional, finite element program for analyzing vertically mechanically laminated lumber is presented. Nodal load‐displacement relationships are formulated for a frame‐to‐frame connector element and a gap element. Frame‐to‐frame connector elements are used to model nails and/or any other discrete mechanical connector used to join individual layers. Each layer may be composed of one or more pieces of lumber butt‐jointed together. A gap element is used to control the transfer of forces across a butt joint once the members forming the joint make contact. Each individual piece of lumber within an assembly is modeled as a series of conventional‐plane frame elements. To determine the accuracy of the nonlinear finite element method of analysis, 10 laboratory‐tested assemblies were modeled. Computer‐predicted deflections were compared with deflections measured up to ultimate assembly loads. Overall good agreement was obtained between predicted and measured load‐point deflections.