Finite Element numerical modelling of the fire resistance of log-house walls

This paper presents a Finite Element (FE) numerical investigation performed on timber log‐house walls with partial thermal insulation, subjected to in‐plane compression and exposed to fire on one side. A key aspect for the design of log‐house walls is represented by geometrical details, like cross‐sectional properties of logs (typically characterised by high depth‐to‐width ratios) and outriggers. The latter ones act as mechanical restraints for the main walls and hence markedly affect their overall load‐carrying capacity. As a result, careful consideration should be given to the choice of these details, due to the possible occurrence of local structural and/or thermo‐mechanical mechanisms. This is the case of exceptional loading conditions like fire load, as the fire resistance of log‐house systems could be affected by a multitude of variables. The FE investigation herein presented follows and extends an earlier research study on an unprotected log‐house wall, where thermal insulation panels (gypsum fibreboard layers) were added to protect part of the wall. The FE method is assessed and validated against a full‐scale furnace test, including a critical discussion of comparative results.