AN IRANIAN engineer this week promised improved earthquake resistance for steel framed structures with a new energy absorbing beam connection.
The bolt-on joint assembly - which takes the form of two tubular sections sandwiched between hinged parallel plates - can absorb twice the energy of a conventional welded joint, he claimed.
Developed by Dr Seyed Vahid Khonsari at the Sharif University of Technology in Iran, the joint has been patented by London's Imperial College. It is claimed to give buildings dramatically improved earthquake and blast resistance - and is replaceable - allowing easy structural repair and retrofitting.
The joint design can be extruded from aluminium or prefabricated from steel, where it can be annealed to reduce the embrittlement effects of welding.
'The energy absorption comes from both the geometry of the joint and from restoring the steel ductility through annealing, ' said Dr Khonsari, who has found through extensive laboratory testing that his design allows four times the axial rotation of a conventional welded joint.