الفهرس | Only 14 pages are availabe for public view |
Abstract Many older structures were designed for static loads, but recently, there has been a growing awareness that some must be designed to resist both dynamic and static loads. Impact load is one of the most dangerous dynamic loads, which can affect structural components. Hence, recently, there is an accelerating interest for researchers to understand the behavior of different structural components under impact loading in order to provide design methods that can withstand this load condition. A large proportion of the surfaces of concrete structures are covered by reinforced concrete slabs (plates) which are often slender elements and consequently are vulnerable to flexural, shear, or a combination of both modes of failure when subjected to impact loading. Concrete slabs usually have openings for different structural and architectural purposes. So, the main aim of this research is to investigate impact load effects on RC plates with openings. For this purpose, a 3D finite element model using Abaqus 6.13 software is presented. The work was established in three stages: In the first stage, the generated FE model was verified against three previously published experimental investigations on RC plates under impact. All verified plates were without openings. The presented FE model was capable of predicting the real behavior of plates under impact as it showed good agreement with the published experimental work results. In the second stage, one analysis of the verified model was selected to investigate dynamic behavior of plates with openings under impact; a series of FE model runs with different positions, numbers and shapes of openings were built and analyzed under the same conditions of the original one. It was concluded that the worst performance of plates regarding to failure pattern and maximum mid-point deflection, was for those with circular and square openings at mid side of plate. Based on previous stage, the last step was to execute an experimental program which was mainly designed to investigate the effect of enhancing plate’s behavior which showed the worst one using two types of reinforcing metal meshes; welded and expanded. The program included casting and testing seven specimens of RC plates with dimensions 1100 × 1100 × 30 mm and reinforced with 1Ø6 every 150 mm. The measured results obtained from experimental investigations were verified with the results of generated FE model runs and an excellent agreement was achieved. It was concluded that using expanded and welded metal meshes, improve the behavior of all plates and reduces effect of opening on deflection and cracking pattern. |