This article summarises an integral part (Chapter III) of the authors’ PhD study that emphasises the importance of time or loading rate effects on the behaviour of welds and welded connection when exposed to fire.
Weld is a metal joining material that is commonly used in steel connections and can affect their governing failure modes during fire events. Despite the importance of welds, very limited studies have been conducted to examine the time-dependent or creep behaviour of welds and welded connections when subjected to elevated temperatures. To address this issue, two experimental programs were conducted to examine the implicit and explicit time-dependent thermal creep behaviour of weld material in transverse welded lap joints.
To investigate the implicit creep behaviour of transverse welded lap joints in fire, two different loading rate scenarios (fast and slow) were used. Peak load capacities for the weld material under both fast and slow loading rates were computed for all temperatures.
To investigate the explicit creep behaviour, the transverse welded lap joints were subjected to a constant load at a specific temperature for 120 min or until failure. Critical times, loads, and temperatures at which weld material fails due to creep were examined.
The experimental results showed that the creep of weld material under implicit and explicit modelling approaches has a large impact on the welded connections for temperatures greater than 450°C and becomes more prominent for larger elevated temperatures.
Read the full article: Time-dependent Behaviour of Welds in Steel Structures Subjected to Fire Temperatures
ABOUT THE AUTHOR
Ahmad is an Associate member of the American Society of Civil Engineering (A.M. ASCE) and has been published in a number of highly ranked journal and peer-reviewed conference publications such as: Journal of Constructional Steel Research (Elsevier), Journal of Structural Engineering (ASCE), Journal of Material in Civil Engineering (ASCE), Journal of Structural Fire Engineering (Emerald), Fire Safety Journal (Elsevier), and Fire Technology (Springer). Ahmad’s work has been also presented in prestigious conferences in the United States, such as: Structures in Fire (SiF), Structure Congress (ASCE), and EMI (ASCE).
Ahmad is an Associate in the Hawkins Built Environment team. Hawkins can investigate the cause of a failure or collapse of a structure during and after a fire. We also provide post-fire analysis for any structure to check its integrity and provide detailed reports for repairing purposes. Our team can provide visual inspection, displacement measurements, test sampling, laboratory testing and examination, and Finite Element Analysis.