FRP reinforcement of stone arch bridges: Unilateral contact models and limit analysis

Summarization: A method for the estimation of the limit load and the failure mode of fiber-reinforced polymer (FRP) reinforced stone arch bridges is hereby presented. Unilateral contact interfaces with friction simulating potential cracks are considered in the finite element model of the bridge. FRP strips are then applied to the intrados and/or the extrados of the arch. The possible failure modes of the reinforced structure are sliding of the masonry, crushing, debonding of the reinforcement and FRP rupture. Identical failure modes arise from the computer simulation and from experiments on reinforced arches published in the literature.Παρουσιάστηκε στο: Composites Part B: Engineerin

Limit load of a masonry arch bridge based on finite element frictional contact analysis

Summarization: The limit load of a stone arch bridge can be identified by the lack of solvability of a finite element analysis including contact interfaces that simulate potential cracks. Opening or sliding at some of them indicates crack initiation. The ultimate load has been calculated by using a path - following (load incrementation) technique. The method is applied on the Strathmashie stone bridge and the results are comparable with the ultimate failure load prediction of the collapse mechanism method and with experimental data published in the literature.Παρουσιάστηκε στο: 5th GRACM International Congress on Computational Mechanic

Shape control and damage identification of beams using piezoelectric actuation and genetic optimization

Summarization: This paper deals with the shape control of beams under general loading conditions, using piezoelectric patch actuators that are surface bonded onto beams to provide the control forces. The mathematical formulation of the model is based on the shear deformation beam theory (Timoshenko theory) and the linear theory of piezoelectricity. The numerical solution of the model is based on the development of superconvergent (locking-free) finite elements using the form of the exact solution of the Timoshenko beam theory and Hamilton’s principle. The optimal values for the locations of the piezo-actuators are determined and optimal voltages for shape control are obtained for cantilever beams by using a genetic optimization procedure. Finally, a simplified related damage identification problem is formulated and solved using static data and genetic optimization.Presented on