There are many modern technologies for strengthening concrete. One of them is Carbon Fiber Reinforcement Polymer (CFRP) sheets. cases that require concrete strengthening, including the weakness from design strength due to exposure elements fires or less control quality. This research provides a theoretical study analyze behavior low RC beams strengthened with CFRP sheets using ANSYS software. T...

This paper presents two time methods to identify weak non-linearities on damping and stiffness of a free vibrating system. Only the displacement is known. The first method is a direct parameter estimation method : using the measured displacement data of the system we obtain by numerical differentiation velocity and acceleration. A linear system containing the parameters is then derived. A least...

Recently, a large amount of studies have been related to nonlinear systems with multi-degrees of freedom as well as continuous systems. The purpose of this paper is to optimize passive vibration absorbers in linear and nonlinear states for an Euler-Bernoulli beam with a nonlinear vibratory behavior under concentrated moving load. The goal parameter in the optimization is maximum deflection of t...

We investigate theoretically the generation of extreme-ultraviolet (EUV) beams carrying fractional orbital angular momentum. To this end, we drive high-order harmonic generation with infrared conical refraction (CR) beams. We show that the high-order harmonic beams emitted in the EUV/soft x-ray regime preserve the characteristic signatures of the driving beam, namely ringlike transverse intensi...

Non-linear modal interactions in the dynamics of a vibrating drop are examined. The partial di!erential equations governing the drop vibrations are formulated assuming potential #ow and incompressibility. The solution is expressed in terms of the eigenfunctions of the (linearized) Laplace operator in spherical coordinates. A small parameter e is introduced to scale the (small) deformation of th...

This paper describes the use of digital photogrammetry for measurement of deflections in concrete beams during destructive testing. A two-video camera system was used to measure vertical deflections with a precision of ±0.25mm (1σ). The system, network design and processing methods are described in detail. Results are presented from several tests of different types of beams. Some of the advanta...

Finite element formulations based generally on classical beam theories such as Euler-Bernoulli or Timoshenko. Sometimes, these two formulations could be problematic expressed in terms of restrictions of Euler-Bernoulli beam theory, in case of thicker beams due to non-consideration of transverse shear; phenomenon that is known as shear locking characterized the Timoshenko beam theory, in case of...

Enhancement of the response of reinforced concrete (RC) beams using fiber-reinforced polymer (FRP) reinforcement bars has become a popular structural technique over the past two decades due to the well-known advantages of FRP composites including their high strength-to-weight ratio and excellent corrosion resistance. Thisstudy presents n...

in this study, application of adaptive neuro-fuzzy inference system (anfis) in forecasting three perspectives (1, 2, and 4 years) ahead of iran’s agricultural products export was compared with arima as the most common econometrics linear forecasting method. for this purpose, iran’s agricultural products export revenues related to 1959-2010, and forecast performance measures such as r2, mad, and...