engleski

The effects of plaster on the behavior of masonry-infilled steel frames under in-plane horizontal loading

Firstly, the effects of plaster on the behavior of one-storey masonry-infilled steel frames under horizontal in-plane static force were experimentally investigated. Tested structures were made in a reduced scale (1:4), with realistic material properties and construction methods. Two types of steel frames were considered: one with high and other with low flexural rigidity of beams and columns. Each type of a frame was tested with three variants of the masonry: (i) only masonry infill, (ii) masonry infill with conventional plaster on both sides and (iii) masonry infill with fiber reinforced plaster on both sides. Masonry elements made of lightweight concrete were used. All frames were loaded successively by a horizontal force in the beam direction, until the collapse of the structure. Characteristic displacements of the frame, strains in steel and masonry, as well as states of cracking in masonry were established for each force increment. After that, previously developed numerical model for nonlinear static and dynamic analysis of planar structures made of concrete, steel and masonry is briefly described. Herein, structures can be made from a single material or from combination of above-mentioned materials. The numerical model is quite simple and it is based on a small number of material parameters. The model can simulate all the main nonlinear effects of individual material, nonlinear behavior on the contact surface between different materials, changes in the system geometry (geometric nonlinearity) and different phases of construction. Lateral structural stability is not included in the model. In this paper, the model was improved by including the effect of plaster on the overall stiffness and strength of the masonry. Full compatibility of displacements between the plaster and the masonry is assumed. The improved model was verified on the previously performed experimental tests. Finally, the most important results of the research were presented.

masonry-infilled frame ; plaster ; static load ; numerical model

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