Public defence, Civil Engineering, MSc Morteza Gholami Haghighi Fard

Title of the thesis: Multi-dimensional modeling of thermal conditions and pyrolysis dynamics in electrical cable fire

Thesis defender: Morteza Gholami Haghighi Fard
Opponent: Prof. Lukas Arnold, University of Wuppertal, Germany 
Custos: Prof. Simo Hostikka, Aalto University School of Engineering

Electrical cables are present in almost every modern building, industrial facility, and transportation system. When exposed to fire, they can contribute to fire development by releasing heat and combustible gases. Understanding and predicting their behaviour is therefore important for improving fire safety and designing safer electrical installations.

Numerical simulations are valuable tools for predicting cable fire behaviour. However, conventional modelling approaches often represent cables as flat materials, whereas real cables have cylindrical geometries and consist of several layers of different materials. This simplification to a flat representation can lead to uncertainties in predicting heat transfer and the thermal decomposition of cables.

This doctoral research develops and validates a two-dimensional numerical modelling approach to better predict the heating, thermal decomposition and fire behaviour of cylindrical materials and electrical cables. The approach was developed progressively through experiments and simulations involving plastic rods, charring wooden rods and, finally, industrial multi-layer electrical cables.

The results demonstrate that accounting for the actual cylindrical geometry and non-uniform heating improves predictions of heat transfer and fire development compared with conventional one-dimensional models. The research also shows that sufficiently intense external heating can overcome the protective capacity of a flame-retardant cable sheath, allowing the inner insulation to ignite and produce an additional peak in heat release.

The developed modelling framework provides a more realistic representation of the physical processes governing cable fire behaviour. It advances cable fire simulations beyond simplified flat-material approximations and provides new possibilities for evaluating and designing safer electrical cables. The findings can support fire safety research and improve the reliability of fire hazard assessments in buildings, industrial facilities, and other environments where electrical cables are present.

Key words: Cable Fire, cone calorimetry modeling, Fire Dynamics Simulator

Thesis available for public display 7 days prior to the defence at Aalto University's public display page. 

Contact information: morteza.gholamihaghighifard@aalto.fi