Innflytelsen av KLT-forbindelsers stivhet på konstruksjoners globale stabilitet

Abstract

This master’s thesis investigates how the stiffness of joints in cross-laminated timber (CLT) affects the global stability of buildings. The main research question addressed is “How is the global stability of CLT structures affected by the stiffness of the connections?” CLT is highlighted as a sustainable and structurally efficient material in response to climate change and urbanization. The focus is on horizontal diaphragms, a less explored area compared to shear walls.

A literature study was conducted to collect stiffness and capacity data from a range of experimental tests, which were then compared to calculated values. An analytical method was developed to calculate the deformation of horizontal CLT-diaphragms, and a sensitivity study was conducted to assess the key parameters on diaphragm deflection. The diaphragm was further evaluated as part of the overall bracing system by analyzing a case building subjected to wind loads.

This thesis concludes that the stiffness and configuration of the horizontal diaphragm influence the distribution of forces to the shear walls, but the connection within the shear walls are the dominant factor governing the building’s overall deformation. Inclined screws showed a great potential for reducing the numbers of fasteners required. The analytical method provided results consistent with FEM-analysis. Further development of the method may enable complete CLT systems to be accurately and efficienty design in spreadsheets, thereby optimizing both structural performance and resource use.