Nonlinear numerical analysis of nine reinforced concrete beams with dimensions (150 x 200 x 1200) width, height and length, respectively, was carried out through the finite element theory using the ANSYS software (version 15) to know the effect of different properties of layers in the one beam on the flexural behavior of reinforced concrete beams. The beams are consisting from two layers for the one cross-section. three beams are similar properties layers and the other six are with different properties layers. The beams differ among them depending on the percentage of Polyethylene terephthalate (PET) fibers added, the location of the fibrous concrete layer as well as the thickness of the layer. PET fibers were added in proportions (0%,0.5%, and 1%) from volume of the one layer, with dimension (50 x 4 x 0.3) mm length, width, and thickness respectively. All beams are reinforced with steel reinforcement (6 mm diameter at the top, 10 mm diameter for reinforcement against shear and 12 mm diameter in the tension area). The mechanical properties of each type of mixture have been studied. It was found that the different properties of the layers significantly affected the flexural behavior of reinforced concrete beams. Also the results of the numerical modeling were very close to the laboratory results obtained from the practical study, where the largest difference between the two studies was 8% and 11% for the load and deflection respectively at the ultimate point
AbstractIn this paper a nonlinear finite element analysis is presented to simulate the fire resistance of reinforced concrete slabs at elevated temperatures. An eight node layered degenerated shell element utilizing Mindlin/Reissner thick plate theory with initial stiffness technique is employed. The proposed model considered cracking, crushing, and yielding of concrete and steel at high temperatures. More complicated phenomena like concrete transient thermal strain and concrete spalling are excluded in the present analysis. The validation of the proposed model is examined against experimental data of previous researches and shows good agreement.Keywords: Fire resistance, Material nonlinearity, Reinforced Concrete Slabs
ABSTRACT: In this study an attempt is made to derive governing equations satisfying equilibrium and compatibility, for multi-layer composite beams with different layers, materials properties and dimensions for linear material and shear connector behavior in which the slip (horizontal displacement) and uplift force (vertical displacement) are taken into consideration. The analysis led to a set of number differential equations containing derivatives of the fourth and third order, number of these equations depending on number of layers forming the beam section. The theory developed for three, four, and five layers. A general formula were derived to find the governing equations (compatibility and equilibrium equations) for any layered composite beam.
ABSTRACT: In this study an attempt is made to derive governing equations satisfying equilibrium and compatibility, for multi-layer composite beams with different layers, materials properties and dimensions for linear material and shear connector behavior in which the slip (horizontal displacement) and uplift force (vertical displacement) are taken into consideration. The analysis led to a set of number differential equations containing derivatives of the fourth and third order, number of these equations depending on number of layers forming the beam section. The theory developed for three, four, and five layers. A general formula were derived to find the governing equations (compatibility and equilibrium equations) for any layered composite beam.