A Monte Carlo-Based Probabilistic Barrier Failure Model for Arbitrary Fire Environment

Failure of building assemblies is a combined results of both heat attack and the mechanical response of the assembly components. The latter could change the integrity of a fire barrier and the pattern of heat transfer. The prediction of failure becomes more complicated when it comes to non-standard fires where real-world experiments are limited. 2-D or 3-D numerical models may provide useful results but their sophistication of use still drives the needs for simple models that offer quick results. A probabilistic barrier failure model is developed to simulate the dynamic process of barrier failure and reflect its stochastic nature. The model comprises a deterministic heat transfer and component response submodel that calculates one-dimensional heat transfer and component responses in fire such as the fall-off of gypsum boards. Further, a Monte Carlo-based probabilistic barrier failure model is created by sampling the influential factors that affect the failure of components. The fire barriers applied in the model include light timber frame and light steel frame assemblies as well as cross laminated timber assembly, but the model is open to other assemblies where data are available. The model results are validated against five room fire tests with good agreements, and an example calculation demonstrates that in a real fire the failure of fire barriers may occur earlier or later than that in the standard fire.