Elastic Rotational Stiffness of an Embedded Steel Plate-Timber Connection A Simplified Solution, Based on an Analytical Study Verified by Numerical Modeling

Abstract

Connections are among the most complex elements to analyze and design within struc tural engineering. They consist of multiple interacting components, involve intricate load-transfer mechanisms, and exhibit nonlinear behavior that is difficult to capture us ing simple assumptions. Although numerical modeling can be employed to evaluate connection behavior and stiffness, it is often computationally demanding and requires careful verification and interpretation. Consequently, connections are frequently idealized in the design phase as either perfectly pinned or fully fixed, and in some cases, assigned an intermediate stiffness. While such simplifications may be acceptable for simple structural systems, they offer limited insight into the governing parameters that influence connection stiff ness. These assumptions restrict the ability to optimize connection design and may be insufficient for structures with demanding performance requirements, such as high-rise hybrid buildings. The objective of this Master’s thesis is to develop a realistic analytical model for the internal parts of a steel-timber connection and the total rotational stiffness in the elastic state. The study considers an embedded steel plate connection, which is widely used due to its aesthetic appeal and ease of on-site installation. To achieve this objective, load paths and structural models are identified for internal parts in connection. By summing the resulting elastic deformations of each part, the total deformation and rotational response are obtained. The analytical results are sub sequently validated and calibrated against numerical simulations, including a 3D solid model and a 2D beammodel. Basedonthisprocess, asimplifiedandverifiedexpression for estimating the rotational stiffness of the embedded steel plate connection is derived. Keywords: embedded steel plate connections, slotted in steel plate-timber connection, elastic rotational stiffness, timber-concrete connection, connection rigidity.