ACCIDENTESCO | Accidental loading in Timber-Encased Steel COmposite members

Project description

The construction sector is increasingly incorporating timber into structural systems to reduce environmental impact and support sustainable building practices. At the same time, modern structures must be designed to withstand accidental actions such as fire, explosions, and impact events, whose frequency and consequences are expected to increase in the coming decades. Timber-Encased Steel Composite (TESC) members represent a promising solution in this context, combining the strength and ductility of steel with the thermal insulation and sustainability of engineered timber. However, their structural performance under extreme thermal and dynamic loading conditions remains largely unexplored.

This research project investigates the behaviour of TESC members subjected to accidental loading scenarios, including fire, blast, impact, and their possible combinations. The timber encasement provides load-bearing thermal protection and represents a sustainable alternative to conventional fire protection systems. Besides, the steel core ensures most of the required structural capacity and ductility. The main objective of the project is to establish the scientific basis for the safe design of TESC members under extreme loading conditions.

For this purpose, the project will evaluate heat transfer mechanisms and thermal degradation, as well as the structural behaviour of steel, timber, and structural adhesives at elevated temperatures and high strain rates. Particular attention will be given to the response of adhesively-bonded steel–timber connections and composite members under fire and dynamic actions, including combined multi-hazard scenarios such as fire-induced explosions. Experimental evidence will be complemented by the development and validation of physics-based models to predict the behaviour of TESC members beyond the benchmark configurations. The research combines thermal and thermomechanical testing of materials and connections, material characterisation at high strain rates, impact and dynamic testing of composite members, and advanced numerical simulations of heat transfer and structural response. Through the integration of experimental investigations and modelling, the project aims to provide fundamental insights into the behaviour of timber-encased steel composite members subjected to accidental loading.

Doctoral students

Marius Hümmer, M.Sc.