Timber-concrete composite structures in fire conditions - Finite Element numerical modelling of tensile tests

The structural behavior of Timber‐Concrete Composite (TCC) slabs, as known, is mainly governed by the load‐bearing capacity of the metal connection between timber and concrete components. There, a key role is assigned to possible changes in stiffness and strength, especially for TCC systems exposed to fire loading. While simplified formulae are available in the literature for the calculation of strength and stiffness properties of screwed connections, most of the influencing parameters for TCC structural systems should be preferably assessed via time and cost consuming experiments in fire conditions. In this regard, the use of refined Finite Element (FE) models can provide strong support for design developments. Key input features ‐ including thermal and mechanical material properties, as well as boundary thermo‐mechanical conditions and interactions ‐ should be however properly assessed and calibrated, including connection detailing. In this paper, an advanced FE approach inclusive of cohesive contacts and damage laws is taken into account, from recent literature applications on timber composites in cold conditions, and preliminarily extended to TCC samples in fire. FE results are assessed towards literature test results, with special care for tensile experiments, including a critical discussion of issues and potentials.