Comparative study of modeling methods used to simulate initial stresses in prestressed beams towards manual analysis

Numerical modeling of the prestressing element that generates prestressed effect in beams has always been considered a big challenge. This research compares two methods of modeling; In the first method we used initial stresses predefined stress and in the second method we used the temperature strain. Concrete damage plasticity model (CDP) was used to model the non-linear behavior of concrete material and an elasto-plastic behavior was applied to ordinary and prestressed reinforcement. Truss elements were used to model ordinary and prestressed reinforcement embedded inside the concrete. As a result, Initial Temperature load method showed less error in bottom and top stresses and cambering of beam in comparison with the basic concept method, than predefined method

Effect of Successive Impact Loads From a Drop Weight on a Reinforced Concrete Flat Slab

Lebanon is one of the countries which are at high risk of experiencing rock falls. In order to ensure public safety, engineers must take into consideration this risk. In the past years, numerous researches were conducted on the behavior of horizontal structural elements, slabs, of different types under dynamic impact load. Reinforced concrete flat slabs are commonly used slabs in residential buildings. To build a profound understanding of the structural behavior of the slabs under such loadings, it is important to investigate the effect of energy dissipation on the equivalent impact force, mid-span deflection and damage pattern. In this study a sample reinforced concrete slab of 500 x 1000 x 100 mm dimensions is considered. The aim of this paper is to find how these factors vary with the increase in energy as the drop load resembling the real rock fall is left to drop freely from different heights 0.6 m and 1 m