Combined Tension and Bending Loading in Bottom Chord Splice Joints of Metal-Plate-Connected Wood Trusses
Combined Tension and Bending Loading in Bottom Chord Splice Joints of Metal-Plate-Connected Wood Trusses by Philip J. O’Regan
Thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Biological Systems Engineering
APPROVED:
Frank E. Woeste, Chairman
Joseph R. Loferski
Audrey G. Zink
John V. Perumpral
May, 1997 Blacksburg, Virginia
Keywords: wood truss, combined loading, truss plate, splice joints, truss design
Combined Tension and Bending Loading in Bottom Chord Splice Joints of Metal-Plate-Connected Wood Trusses by Philip J. O’Regan Frank E. Woeste, Chair Biological Systems Engineering (ABSTRACT)
Metal-plate-connected (MPC) splice joints were tested in combined tension and bending to generate data that were used in the development of a design procedure for determining the steel net-section strength of bottom chord splice joints of MPC wood trusses. Several common wood truss splice joint configurations were tested at varying levels of combined tension and bending loading. The joint configurations were 2x4 lumber with 20-gauge truss plates, 2x6 lumber with 20-gauge truss plates, and 2x6 lumber with 16-gauge truss plates. All the joints tested failed in the steel net-section of the truss plates. The combined loading was achieved by applying an eccentric axial tension load to the ends of each splice joint specimen. Three structural models were developed to predict the ultimate strength of the steel net-section of the splice joints tested under combined tension and bending loading. The test data were fitted to each model, and the most accurate model was selected. Data from other published tests of splice joints were used to validate the accuracy of the selected model. A design procedure for determining the allowable design strength of the steel net-section of a splice joint subjected to combined tension and bending was
Thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Biological Systems Engineering
APPROVED:
Frank E. Woeste, Chairman
Joseph R. Loferski
Audrey G. Zink
John V. Perumpral
May, 1997 Blacksburg, Virginia
Keywords: wood truss, combined loading, truss plate, splice joints, truss design
Combined Tension and Bending Loading in Bottom Chord Splice Joints of Metal-Plate-Connected Wood Trusses by Philip J. O’Regan Frank E. Woeste, Chair Biological Systems Engineering (ABSTRACT)
Metal-plate-connected (MPC) splice joints were tested in combined tension and bending to generate data that were used in the development of a design procedure for determining the steel net-section strength of bottom chord splice joints of MPC wood trusses. Several common wood truss splice joint configurations were tested at varying levels of combined tension and bending loading. The joint configurations were 2x4 lumber with 20-gauge truss plates, 2x6 lumber with 20-gauge truss plates, and 2x6 lumber with 16-gauge truss plates. All the joints tested failed in the steel net-section of the truss plates. The combined loading was achieved by applying an eccentric axial tension load to the ends of each splice joint specimen. Three structural models were developed to predict the ultimate strength of the steel net-section of the splice joints tested under combined tension and bending loading. The test data were fitted to each model, and the most accurate model was selected. Data from other published tests of splice joints were used to validate the accuracy of the selected model. A design procedure for determining the allowable design strength of the steel net-section of a splice joint subjected to combined tension and bending was
References: Appendix B Tables of Ratios of the Median to the Fifth Percentile of the Compression Parallel-To-Grain Strength for Five Species Groups of Dimension Lumber, Adapted from Green and Evans (1987) Table B.1 Moisture Content (%) 12 12 12 12 12 12 12 12 12 15 15 15 15 15 15 15 15 15 Summary of compression property estimates for Douglas Fir-Larch lumber, adapted from Green and Evans (1987) Table B.2 Moisture Content (%) 12 12 12 12 12 12 12 12 12 15 15 15 15 15 15 15 15 15 Summary of compression property estimates for Douglas Fir (South) lumber, adapted from Green and Evans (1987) Table B.3 Moisture Content (%) 12 12 12 12 12 12 12 12 12 15 15 15 15 15 15 15 15 15 Summary of compression property estimates for Hem-Fir lumber, adapted from Green and Evans (1987)