Moment Connection for Quick Assembly of Timber Portal Frame Buildings: Theory and Validation

Abstract

This paper provides an overview of a moment connection for use in prefabricated timber portal frame buildings. The connection, known as the quick-connect joint, uses rods housed in timber sleeves that are placed on the outside of the main portal members to create a semirigid moment connection similar to those used in steel portal frames. Timber sleeves are connected to the main portal members using fully threaded, self-drilling timber screws that have high strength and stiffness characteristics. These characteristics limit connection slip and limit joint rotation. The quick-connect connection allows manufacture to take place offsite, thus reducing onsite plant and labor costs. A proposed design procedure is introduced in this paper. This procedure uses individual component deflections to calculate the overall rotation of members at the joint. Accurate rotation predictions allow for more efficient member design. Full-scale testing of a timber beam to steel column, and timber beam to timber column knee joint, is discussed. Results show that the quick-connect joint does not constrain the portal member sizes. Full-scale test results are used to verify the proposed design procedure. Test and analytical results show good correlation. The authors believe the quick-connect connection allows for more efficient and competitive design, manufacture, and erection of timber portal frame buildings by providing a joint and design procedure that is as easily used as those in the steel industry.