Interstory Drift Stiffness of MEGANT E Connector
This White Paper is a supplement to a previously published White Paper, by referencing both monotonic and cyclic testing data obtained from Oregon State University (OSU) to evaluate the behavior of pre-engineered MEGANT E and custom glulam beam-to-column connections.
Beam-to-column connectors are primarily intended to withstand gravity shear forces. Nevertheless, during an earthquake, the connector needs to endure significant lateral deformations and rotations while supporting the gravity forces. These connectors can either be pre-engineered or custom designed, but it is necessary to understand and obtain accurate information about their behavior to ensure proper engineering design. Engineers should ensure that their widespread use in mass timber buildings is appropriate, regardless of the connector type employed.
In seismic design, the primary structural features that are of utmost importance include the natural period, stiffness, damping, and ductility. It is imperative to determine a structure’s fundamental period in advance, as it enables structural engineers to estimate the seismic design base shear force and acceleration response of the structure, which are crucial factors in ensuring the safety and resilience of the structure. An increase in connection stiffness leads to higher design base shear forces for the same ground motion, while the corresponding education in lateral drift does not occur in the same proportion. Furthermore, an increase in connection stiffness leads to a higher acceleration response of the structure, which can result in further structural and non-structural damage. Thus, a highly stiff connection may not be the best solution in mitigating dynamic loading since an optimal structure design should aim to minimize the acceleration response and associated base shear forces while maintaining an acceptable amount of lateral deformations.