A computer simulation and analysis of strength and failure for glue-laminated beam

As one of the major engineering construction materials, glue laminated timber beams with significant advantages over other structural materials have been used worldwide for more than five decades. In order to fully utilize this engineered material, computer modeling based on the material orthotropic behavior and failure modes under loading will provide useful information for the evaluation and manufacture.;The objectives of this dissertation research are: (1) to develop a computer tool for industrial users to design, analyze, and test glue laminated timber beams, (2) to apply finite element methods, failure theory, and fracture mechanics into the glue laminated timber beam analysis and design process, and (3) to develop a computer-generated graphic system that would illustrate the property characteristics and failure behavior of a loaded glue laminated beam.;Examinations and modifications of previous finite element programs that were developed to determine stresses and displacements of the glue laminated beam have been conducted. A comprehensive computer program in FORTRAN, set up specifically for the Macintosh IIcx and above computer systems, has been developed. Failure theories and fracture mechanics have been applied in simulation and the models included the Norris and the Tsai-Hill failure theories and the fracture mechanics of mode I and mode II. Simulations of the beam lay-ups, properties, and failure behavior are the most important feature in this computer program. A graphic system was developed that would assist in the visualization of the simulation process of beam assembly, loading, and failing. Glue laminated timber beams with visual grade classifications such as 24f-v4 and with dimensions as large as 57 ft long by 3 ft deep by 5.125 in. wide can be processed by the finite element program and presented in graphical form. Distributions of joints and knots in an assembled and loaded beam, as well as the stress field, deflection, and failure characteristics can be displayed as graphic simulations.;The computer package developed through this dissertation provides users with a valuable tool to analyze failure behaviors and to determine strengths for glue laminated beams. This flexible and cost-effective program can be adopted by both the wood industry and the academic community.