STIMBER | Novel veneer-wrapped steel columns

Project description

Timber is increasingly recognised as a renewable and environmentally sustainable building material. However, it still presents inherent mechanical limitations, such as lower strength compared to steel and long-term degradation under sustained loading. The STIMBER project explored an innovative hybrid structural concept that combines the advantages of both materials in a single load-bearing member.

In this study, a novel steel–timber composite column was developed, consisting of a slender hollow steel section wrapped with multiple thin layers of timber veneer. The veneer acts as a passive confinement shell around the steel core, delaying local buckling and improving the overall stability of the column. The fabrication process itself required appropriate methods for wrapping, bonding, and curing the veneers to ensure effective mechanical interaction between steel and timber. An extensive experimental programme was conducted on short and slender column specimens, investigating parameters such as veneer thickness, fibre orientation, and column slenderness. The tests confirmed that the veneer wrapping significantly enhanced both stiffness and load-bearing capacity compared to bare steel columns. Finite element simulations reproduced the global and local response of the test specimens and extended the findings of the experimental campaign to further configurations.

By integrating fabrication research, laboratory testing, and advanced numerical modelling, the project demonstrated the technical feasibility and structural efficiency of veneer-wrapped steel-timber composite columns.