Much previous experimentation related to wood structures has employed monotonic loading to replicate static situations. However, instances of natural hazards have raised interest in the response of structural connections to dynamic loads. This increased interest led the Consortium of Universities for Research in Earthquake Engineering (CUREE) to develop a testing protocol for reverse-cyclic loading, which involves cycling loads through zero in order to test specimens in both tension and compression. With the CUREE testing protocol in place, recent research has been devoted to understanding the effects of reverse-cyclic loading on multiple-fastener connections. Experimentation by Heine (2001), Anderson (2002), Billings (2004) and others contributed to a better understanding of bolted connection behavior under reverse-cyclic loading. However, some questions remained. Billings was unable to consistently produce yield modes III and IV, meaning that her suggested bolt spacing of seven times the bolt diameter (7D) could not be applied to connections subject to these yield modes without further testing. In addition, the work of Anderson and Billings raised questions regarding the proper measurement of bending yield strength in bolts and the relationship between the bending yield strength and the tensile yield strength. These topics are each addressed by this project and thesis report. Results of the connection testing presented in this report can be used in conjunction with the work of Anderson and Billings to critically evaluate the 4D between-bolt spacing recommended by the National Design Specification (NDS) for Wood Construction (AF&PA, 2001). Results of the bolt testing provide a supplement to the search for a reliable method for the measurement of bending yield strength in bolts. / Master of Science

This thesis presents the results of testing to determine if spacing between bolts in a multiple-bolt, single-shear connection subjected to natural hazard loading affects seven strength and serviceability parameters: maximum load, failure load, E.E.P. yield load, 5% offset load, elastic stiffness, E.E.P. energy, and ductility ratio. This research also determines if a statistical difference exists between previously published research for 4D spacing as compared to results produced by this research for five alternate spacings: 8D, 7D, 6D, 5D, and 3D. Finally, this research determines which of the spacings examined: 8D, 7D, 6D, 5D, 3D; produced the most optimal results for each examined strength and serviceability parameter where optimization is based on economy and performance. Three connection configurations with five different spacings between bolts were subjected to reverse cyclic loading for a total of one hundred and fifty tests. The reverse cyclic protocol was based on recommendations by the Consortium of Universities for Research in Earthquake Engineering (CUREE) for testing woodframe structures. The same connection configurations were also subjected to monotonic loading for an additional forty-five tests. Results of this research can be used to evaluate the current design recommendation presented in the National Design Specification (NDS) for Wood Construction (AF&PA, 2001) of spacing bolts at four times the bolt diameter (4D) to determine if a different spacing should be recommended for natural hazard loading conditions. / Master of Science