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Abstract
The purpose of this research project was to design a coupling beam connection to be utilized in mid- to high-rise mass timber framed buildings. Coupling beams connect two shear walls together and transfer shear forces between the two, forcing them to work together as one composite member, allowing the structure to resist higher lateral loads. The connections analyzed during this project include an I-shape connection, and two knife plate connections. The goal of the analysis was to create a steel connection that would yield and exhibit ductile behavior prior to any other connection elements, in this case CLT and bolts, yielding. After analyzing the I-shape model, the connection was able to withstand a shear force greater than that of the CLT member. The knife plate iterations had different results. Preliminary calculations were conducted, and the conclusion was that a shear force of 30 kip applied to either knife plate configuration would result in a ductile failure of the steel plate, prior to any yielding of the CLT member or bolts. Table 7 summarizes the data values from the analysis. Figure 45 and Figure 63 show that both connections were able to transition from the elastic region to the plastic on the nonlinear force versus displacement graph. The maximum deformation for the knife plate connection at yield point is [KP] 0.224 inches at a load of 36 kip. For the knife plate with reduced cross section [KPRC] connection, the maximum deformation is 0.123 inches with a 15.6 kip load applied. The maximum stresses at yield point for KP and KPRC are 47 ksi and 38 ksi, respectively. Additional future work would involve creating more connection iterations and putting together a design guide for the connections to implement these designs in mass timber construction projects.