Professor Santiago Hernandez from the University of La Coruña, School of Civil Engineering, gave a special lecture at Ashurst Lodge on the “Design Optimization of Large Engineering Structures”, with particular reference to the Messina Bridge.
Professor Hernandez, a renowned specialist in Optimum Design, is also a member of the Board of Directors of WIT and Adjunct Professor at the Institute.
He has participated in the design of the Messina Bridge on behalf of one of the consulting engineering companies which tendered for this ground-breaking project.
An important part of the design is achieving the optimization of the deck, which is subject to flutter forces as well as other usual loads. The general shape and dimensions of the deck were defined by the optimal requirements, and hence the most important optimization parameters are the plate thickness.
Optimum design of the deck requires not only the static sensitivity analysis problems but also the sensitivity of the design to frequencies and modeshapes, and the resultant sensitivity analysis for flutter. These parameters are then used in the optimizing algorithm.
Professor Hernandez’s group has pioneered the sensitivity analysis of dynamic problems subjected to flutter.
Another interesting application of structural optimization studied by his group involves the rear part of the Airbus A380. This is the section towards the tail and is comprised of a large number of stringers and panels. The optimization of the panels, although composites, is done using Von-Mises stresses. The objective function in this case is the skin thickness. There are nearly 30,000 shell elements involved, plus a similar quantity of stringers.
The presentation helped to highlight the importance of the work being carried out by Professor Hernandez’s group in La Coruña, and its emphasis on industrial applications.
Wessex Institute