Calculation Methods of CFRP Tendons Stress in Two-Span Prestressed Continuous Beams

2013 ◽  
Vol 859 ◽  
pp. 60-63
Author(s):  
Chong Xi Bai ◽  
Xin Yan Shao ◽  
Qiu Ping Wang
Keyword(s):  
Simulation Analysis ◽  
Full Range ◽  
Fiber Reinforced Polymer ◽  
Analysis Method ◽  
Stress Increment ◽  
Range Analysis ◽  
Reinforced Polymer ◽  
Continuous Beams ◽  
Unbonded Tendons ◽  
Deformation Compatibility

Crack width, deflection and load bearing capacity of two-span concrete continuous beams partially prestressed with unbonded carbon fiber reinforced polymer (CFRP) tendons can be calculated accurately, the first premise is to calculate reasonably the stress increment of CFRP tendons. However, the law of stress increment of unbonded tendons is unclear. Moment-curvature analysis method and deformation compatibility condition were used to compile nonlinear full-range analysis programs of this kind of continuous beam. The comparison between simulated results and tested results of stress in CFRP tendons indicates that the simulation analysis programs are reliable.

Research on Stress Increase of Unbonded Tendons at Ultimate in Prestressed Concrete Continuous Beams

2012 ◽  
Vol 166-169 ◽  
pp. 1554-1557
Author(s):  
Xiao Dong Wang ◽  
Wen Zhong Zheng ◽  
Ying Wang
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Simulation Analysis ◽  
Analysis Method ◽  
Stress Increase ◽  
Continuous Beams ◽  
Unbonded Tendons ◽  
Index Ratio ◽  
Prestressed Reinforcement ◽  
Rational Evaluation

Rational evaluation for stress increase of unbonded tendon at ultimate is the basis to exactly compute flexural load bearing capacity of unbonded prestressed concrete beams. Moment-curvature nonlinear analysis method is adopted to compile programs for calculating stress increase at ultimate in unbonded prestressed continuous beams. The precision of the method is proved by comparing results of 16 experimental two-span unbonded prestressed continuous beams to the prediction value of stress increase at ultimate. Based on the simulation analysis, law of the influence of some basic factors to stress increase at ultimate in unbonded tendons in continuous beams is obtained, such as non-prestressed reinforcement index, prestressed reinforcement index, ratio of span to depth and loading type. Then formulas for calculating stress increase at ultimate in unbonded tendons in prestressed concrete continuous beams were established.

scholarly journals Neural Networks—Deflection Prediction of Continuous Beams with GFRP Reinforcement

2021 ◽  
Vol 11 (8) ◽  
pp. 3429
Author(s):  
Željka Beljkaš ◽  
Nikola Baša
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Experimental Research ◽  
Fiber Reinforced Polymer ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Continuous Beams ◽  
Glass Fiber Reinforced ◽  
Gfrp Reinforcement

Deflections on continuous beams with glass fiber-reinforced polymer (GFRP) reinforcement are calculated in accordance with the appropriate standards (ACI 440.1R-15, CSA S806-12). However, experimental research provides results which differ from the values calculated pursuant to the standards, particularly when it comes to continuous beams. Machine learning methods can be applied for predicting a deflection level on continuous beams with GFRP (glass fiber-reinforced polymer) reinforcement and loaded with a concentrated load. This paper presents research on using artificial neural networks for deflection estimation and an optimal prediction model choice. It was necessary to first develop a database, in order to train the neural network. The database was formed based on the results of the experimental research on continuous beams with GFRP reinforcement. Using the best trained neural network model, high accuracy was obtained in estimating deflection, expressed over the mean absolute percentage error, 9.0%. This result indicates a high level of reliability in the prediction of deflection with the help of artificial neural networks.

Study on the stiffness degradation in concrete continuous beam with externally prestressed CFRP tendons under fatigue loading

2021 ◽  
pp. 136943322199249
Author(s):  
Xing Li ◽  
Jiwen Zhang ◽  
Jun Cheng
Keyword(s):  
Fatigue Life ◽  
Fatigue Loading ◽  
Load Level ◽  
Fiber Reinforced Polymer ◽  
Stiffness Degradation ◽  
Test Results ◽  
Reinforced Polymer ◽  
Continuous Beams ◽  
Practical Engineering ◽  
Good Agreement

This paper presents fatigue behaviors and the stiffness degradation law of concrete continuous beams with external prestressed carbon fiber-reinforced polymer (CFRP) tendons. Three specimens were tested under fatigue loading, and the influence of different load levels on the stiffness degradation and fatigue life were studied, and it was found that the stiffness degradation of three test specimens exhibited a three-stage change rule, namely rapid decrease, stable degradation, and sharp decline, but there are obvious differences in the rate and amplitude of stiffness degradation. The load level has a significant influence on the fatigue life of the test specimens. An analytical model with load level considered was proposed to calculate the residual stiffness and predict the stiffness degradation, which is in good agreement with the test results. The model of stiffness degradation presents a possible solution for practical engineering applications of concrete continuous beams with externally prestressed CFRP tendons subjected to different fatigue loadings.

Simulation Analysis of Secondary-Load Rc Square Columns Strengthened with IFRP

2014 ◽  
Vol 501-504 ◽  
pp. 578-582
Author(s):  
Liang Hsu ◽  
Ming Long Hu ◽  
Jun Zhi Zhang
Keyword(s):  
Finite Element ◽  
Simulation Analysis ◽  
Element Model ◽  
Fiber Reinforced Polymer ◽  
Experimental Result ◽  
Compression Process ◽  
Reinforced Polymer ◽  
Secondary Load ◽  
The Impact ◽  
The Finite Element Model

Considering secondary load, simulate the axial compression process of reinforced concrete square columns strengthened with igneous rock fiber reinforced polymer with Abaqus. Make a comparison between the simulation result and experimental result. The finite-element model can simulate the experiment preferably. And the impact of lagged strain is very obvious.

Buckling Analysis of Pultruded Fiber Reinforced Polymer Plastic Plate: Application of Simplified Buckling Analysis

2017 ◽  
Vol 753 ◽  
pp. 103-108
Author(s):  
Jong Ho Yoo ◽  
Sun Hee Kim ◽  
Won Chang Choi ◽  
Soon Jong Yoon
Keyword(s):  
Material Properties ◽  
Orthotropic Material ◽  
Geometric Mean ◽  
Buckling Analysis ◽  
Fiber Reinforced Polymer ◽  
Analysis Method ◽  
Fiber Reinforced ◽  
Buckling Strength ◽  
Advantages And Disadvantages ◽  
Reinforced Polymer

The pultruded fiber reinforced polymer plastic (PFRP) is one of the most actively studied materials for structural member in construction industries. In this study, a buckling analysis of PFRP plate is conducted by two analysis methods. First, a buckling strength of PFRP plate is calculated by the exact orthotropic plate buckling analysis. Second, simplified buckling analysis for PFRP plate is conducted by using approximate orthotropic material properties. The approximate orthotropic material properties are geometric mean value of longitudinal and transverse material properties of original PFRP plate. As a result of buckling analysis, buckling strength of PFRP plate for each analysis method can be obtained. From the comparison between these results, advantages and disadvantages of each analysis method are discussed. In addition, it is also discussed whether the simplified buckling analysis method for PFRP plate is applicable for the design.

Simulation Analysis on Wastewater Anaerobic Tank Stench in Collecting Hood with Properties of Environmental Materials

2014 ◽  
Vol 915-916 ◽  
pp. 913-916
Author(s):  
Zhao Du ◽  
Ning Du ◽  
Yu Jie Chen
Keyword(s):  
Simulation Analysis ◽  
Fiber Reinforced Polymer ◽  
Turbulent Model ◽  
Reinforced Polymer ◽  
Environmental Material ◽  
Environmental Materials ◽  
Computational Fluid Dynamics Cfd ◽  
The Relationship ◽  
Geometrical Boundary

The relationship is very important between geometrical boundary parameters and mechanical ventilation airflow pattern of wastewater gas-collecting hood. Computational fluid dynamics (CFD) is an effective approach to study with standard κε turbulent model. CFD predominate results show that: the exhaust flow, tuyere pressure, velocity and pollutant concentration had a greater influence on the flow field distribution. Fiber Reinforced Polymer (FRP) stench-collecting hood can be used to anaerobic tank in long-term because of its environmental material properties for acid and wet.

scholarly journals Experimental Analysis of Continuous Beams Made of Self-Compacting Concrete (Scc) Strengthened with Fiber Reinforced Polymer (Frp) Materials

2021 ◽  
Vol 11 (9) ◽  
pp. 4032
Author(s):  
Žarko Petrović ◽  
Bojan Milošević ◽  
Slobodan Ranković ◽  
Biljana Mladenović ◽  
Dragan Zlatkov ◽  
...  
Keyword(s):  
Experimental Analysis ◽  
Failure Modes ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Engineering Practice ◽  
Fiber Reinforced ◽  
Self Compacting Concrete ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Continuous Beams

Strengthening of concrete structures is applied as a solution for various deterioration problems in civil engineering practice. This also refers to the structures made of self-compacting concrete (SCC), which is increasingly in use, but there is a lack of research in this field. This paper presents an experimental analysis of flexural behavior of reinforced concrete (RC) continuous beams made of SCC, strengthened with fiber reinforced polymer (FRP) materials (glass (GFRP) and carbon (CFRP) bars, CFRP laminates), by the use of near surface mounted (NSM) and externally bonded (EB) methods. Six two-span continuous beams of a total length of 3200 mm, with the span between supports of 1500 mm and 120/200 mm cross section, were subjected to short-term load and tested. The displacements of beams and the strains in concrete, steel reinforcement, FRP bars and tapes were recorded until failure under a monotonically increasing load. The ultimate load capacities of the strengthened beams were enhanced by 22% to 82% compared to the unstrengthened control beam. The ductility of beams strengthened with GFRP bars was satisfactory, while the ductility of beams strengthened with CFRP bars and tapes was very small, so the failure modes of these beams were brittle.

scholarly journals NONLINEAR MULTILEVEL ANALYSIS OF REINFORCED CONCRETE FRAMES

2016 ◽  
Vol 7 (4) ◽  
pp. 168-176 ◽  
Author(s):  
Pui Lam Ng ◽  
Jeffery Yuet Kee Lam ◽  
Albert Kwok Hung Kwan
Keyword(s):  
Reinforced Concrete ◽  
Multilevel Analysis ◽  
Crack Opening ◽  
Full Range ◽  
Analysis Method ◽  
Concrete Frames ◽  
Range Analysis ◽  
Strength Deterioration ◽  
Rc Frames ◽  
Frame Member

Full range analysis of reinforced concrete (RC) members covering the post-crack and post-peak regimes is important for obtaining the deformation response and failure mode of structural members. When a RC member is subject to an increasing external load, the critical sections would exhibit cracking and/or softening. Due to stress relief effect in the proximity of crack opening and plastic hinging, unloading may occur at the adjacent regions. The variable stress states of discrete sections would lead to sectional variation of stiffness, which could not be accounted for by conventional structural analysis methods. In this paper, a nonlinear multilevel analysis method for RC frames whereby the frame members are divided into sub-elements and sectional analysis is utilised to evaluate stiffness degradation and strength deterioration is developed. At sectional level, the secant stiffness is determined from moment-curvature relation, where the curvature is evaluated based on both transverse displacements and section rotations of the frame member. Unloading and reloading behaviour of concrete and reinforcing steel is simulated. In implementing the multilevel analysis, secant iteration is performed in each step of displacement increment to obtain the convergent solution satisfying equilibrium. Numerical example of RC frame is presented to demonstrate the applicability and accuracy of the proposed nonlinear multilevel analysis method.

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