Journal of Civil Engineering Research 2016, 6(2): 40-46 DOI: 10.5923/j.jce.20160602.03 Effect of High Temperature on the Strain Behavior in Post-Tensioning Concrete Beams by Using Finite Element Method (ANSYS Program) Amer Farouk Izzet, Zahra'a Hussein Dakel * B.Sc. in Civil Engineering, University of Baghdad College of Engineering Civil Engineering Department, Baghdad, Iraq Abstract This research is conducted to study the of effect of high temperature on the strain Behavior in post-tensioning concrete beams exposed to fire flame. The exposure of these beams to fire causes changes in their structural behavior. Finite element method was used to idealize the effect of burning by fire flame exposed to post-tensioning concrete beams. The beams that were subjected to fire flame at temperature levels of (300, 500 and 700 °C) for 1 hour period of exposure. A three-dimensional nonlinear finite element model was adopted to investigate the structural behavior of post-tensioning concrete beams specimens with and without exposure to burning. Good agreement was observed between the adopted finite element model results and experimental results of [11]. It is found that the theoretical values of beam strain exceeds values by a margin the experimental [11] ranging between (1-23%) after burning for the analyzed beams specimens. The adopted finite element analysis showed, also, good agreement with experimental results of [11] throughout the load-deflection behavior before and after burning. Keywords Post-Tension, Finite element, Burning 1. Introduction Pre-stressed concrete is widely used in the construction industry of buildings, bridges, towers, pressure vessels and offshore structures. For architecture requirements many buildings need long span with small depth, in this case the pre-stressed elements are the economic solution. Traditionally, laboratory testing was used to investigate the structural behavior of post-tensioned reinforced concrete beams under static loads. However, such reliance on time consuming and expensive laboratory testing has hindered progress in this area. The advances in the fields of computer aided engineering and finite element method during the last two decades have changed this situation significantly in many engineering fields. In the present study, three dimensional numerical analysis were used to analyses the tested seven pre-stressed post-tensioned concrete beams after exposing six of them to the effect of fire and static loads using finite element analysis (FEA) approach by using ANSYS 2011 software. The methodology and modeling techniques for the numerical analysis are presented in this paper. [10] Proposed relationships for normal concrete to * Corresponding author: engzahra67@yahoo.com (Zahra'a Hussein Dakel) Published online at http://journal.sapub.org/jce Copyright © 2016 Scientific & Academic Publishing. All Rights Reserved provide efficient modeling and to meet fire performance criteria of the behavior of concrete exposed to fire .the proposed relationships are for both the peak strain of concrete at elevated temperatures. T ) 6 ( ^ 10 2 0028 . 0 max      (1) Applying equation (1) gives the following peak strain as shown in Table (1): Table (1). Peak strain for concrete Temperature Peak strain value 300°C 0.0034 500°C 0.0038 700°C 0.0042 1.1. Numerical Methods There are many practical engineering problems for which the exact solution cannot be obtained. This may be attributed to either the complex nature of governing differential equations or the difficulties that arise from the boundary and initial conditions. To achieve the solution for this problem numerical approximation was adopted. There are two common numerical methods; these are:  Finite difference method.  Finite element method. Finite element method is a numerical procedure that can be applied to obtain solution to a variety of problems in