Corrosion of steel reinforcement in concrete structures and bridges is a major problem facing the departments of transportation worldwide. In the United States, maintenance and replacement costs are measured in billions of dollars. Salt environment in hot climate and the use of deicing salts in cold regions have resulted in steady deterioration of bridge decks due to corrosion. These concerns h...

In this paper, the extended finite element method (XFEM) is employed to investigate the statics and vibration problems of cracked isotropic bars and beams. Three kinds of elements namely the standard, the blended and the enriched elements are utilized to discretize the structure and model cracks. Two techniques referred as the increase of the number of Gauss integration points and the rectangle...

In this study, the natural frequencies and mode shapes of beams without cracks and cracked Timoshenko beams is calculated with different boundary conditions using finite element method. The energy method is used to solve the equations. Hardness and softness matrices for Timoshenko beam without crack are obtained by solving the potential and kinetic energy equations. Then for investigation of cr...

The utilization of unbounded external reinforcing bars is one of the strengthening methods used after loading stage and before failure. The method has been used in different forms to strengthen members of reinforced concrete structures. To investigate the effect of utilization of post-tensioned reinforcing bars in this method of strengthening, a number of reinforced concrete beams was tested. S...

concrete beams reinforced with glass fiber reinforced polymer (gfrp) bars exhibit large deflections and crack widths as compared with steel reinforced concrete beams due to the low modulus of elasticity of gfrp bars. different studies show that aci 318 equation for the effective moment of inertia ie does not predict deflection well for frp reinforced concrete beams. the purpose of this paper is...

The application of external post-tensioned steel bars as an effective way to strengthen an existing bridge has been so far used in many different countries. In recent decades, however, they have been replaced by bars made from Carbon Fiber Reinforced Polymer (CFRP), as a material with high tensile strength and corrosion resistance, to address several concerns with steel bars such as their appli...

in this paper, the crack detection and depth ratio estimation method are presented in beamlikestructures using elman networks. for this purpose, by using the frequencies of modes asinput, crack depth ratio of each element was detected as output. performance of the proposedmethod was evaluated by using three numerical scenarios of crack for fixed-simply supportedbeam consisting of a single crack...

Cracks cause to change dynamic response of beams and make discontinuity in slope of the deflection of the beams. The dynamic analysis of the Euler-Bernoulli cracked beam on the elastic foundation subjected to the concentrated load is presented in this paper. The stiffness of the elastic foundation and elastic supports influence on vibrational characteristics of the cracked beam. The Dynamic Gre...

Abstract:   The use of Concrete beams reinforced with a combination of fiber reinforced polymer (FRP) and steel bars has increased dramatically in recent years, due to improvement in strength and flexural ductility simultaneously. In this paper, we proposed a new equation for estimating the effective moment of inertia of hybrid FRP-steel reinforced concrete (RC) beams on the basis of the...