According to a new study performed at The University of Alabama in Huntsville (UAH), when a bomb explodes or fire breaks out, a building constructed or modified with an engineered composite presently confined to unique applications could buy the occupants extra time to get out.
Dr. Elias Ali says he thinks functionally graded material will be the future of engineered materials. Image Credit: Michael Mercier | University of Alabama in Huntsville.
Functionally graded material (FGM), which is a recently developed composite marked by the slow variation of material properties throughout its thickness, is considered to be an efficient bomb-resistant material in structural uses. This is in accordance with a new study headed by Dr. Elias Ali, a lecturer in the Department of Civil Engineering at UAH, a part of the University of Alabama System.
The composite increased the collapse load by around 12% for cold-formed steel beams and 18% for columns. A previous study headed by Dr. Ali discovered that FGM utilized as the sheathing material for buildings could retard the spread of fire from reaching the primary structural parts of a building by up to 14% when compared to gypsum board.
FGM has been dubbed as the so-called “the holy grail” of composite materials. At present, its high manufacturing cost and the difficulties of mass production and forming it into complicated shapes restrict its use to advanced technologies like those in the naval ship construction, aerospace industry and on-demand fabricated uses.
The challenge the material science and structural engineering research community faces in terms of FGM composite is the lack of availability. So far, there are only a few companies devoted to manufacturing it, and they are confined mainly to the aerospace and defense industries.
Dr. Elias Ali, Lecturer, Department of Civil Engineering, The University of Alabama in Huntsville
Ali is also a part of the University of Alabama System.
FGM consists of a special and different material property obtained from its separate constituent materials, yet preserves their advantages.
Because of the improved mechanical properties, FGM can be useful in extreme loading environments with high thermal, chemical or mechanical stresses that would cause a single-material part to fail.
Dr. Elias Ali, Lecturer, Department of Civil Engineering, The University of Alabama in Huntsville
Dr. Ali and his collaborator, Dr. Fadi Althoey, the Department of Civil Engineering program head and an assistant professor at Najran University in Saudi Arabia, made use of computer modeling and simulation to study a metal or ceramic composite material used for fire protection and blast resistance. They carried out broad material gradation sensitivity parametric studies on the performance of the composite material in extreme loading surroundings.
The same qualities that are shown by the study make FGM appealing for bomb-hardened buildings and it also could prove useful in an earthquake and severe weather zones, states Dr. Ali, though his study did not include these kinds of tests.
From our numerical investigation, this composite material can result in a resilient structural system in fire and blast cases. Their performance in earthquakes and hurricanes needs to be further investigated. However, we can predict from our study that they can be useful in such extreme events.
Dr. Elias Ali, Lecturer, Department of Civil Engineering, The University of Alabama in Huntsville
The numerical simulation results offer a new material solution for structures in extreme loading surroundings. According to Dr. Ali, an experimental investigation is required to make the research complete.
According to Dr. Ali, the application of material having a graded interface in structural engineering is still in the initial stage. Numerous methods could be employed in the manufacturing of FGMs.
Ali stated, “As an emerging technology, additive manufacturing (AM) is capable of producing fully functional parts in a wide range of materials including metallic, ceramic, polymers, and their combination in the form of composite, hybrid or functionally graded materials. AM also offers a high degree of control over spatial variation of materials.”
Ali expects that performing additional studies into the materials will ultimately result in the extensive availability of FGM for applications on structures and crucial infrastructures.
Ali added, “Since FGM is a multi-functional material, I would anticipate the use of the material in many applications including new buildings as well as in retrofit works. I would envision that it will be the future of engineered materials.”
Journal Reference:
Ali, E & Althoey, F (2022) Numerical Investigation on Blast Response of Cold-Formed Steel Framing Protected with Functionally Graded Composite Material. Buildings. doi.org/10.3390/buildings12020118.