Fatigue Assessment of Concrete Members Strengthened by FRP Materials

2014 ◽  
Vol 617 ◽  
pp. 221-224 ◽  
Author(s):  
Alena Čavojcová ◽  
Martin Moravcik
Keyword(s):  
Fatigue Damage ◽  
Cross Section ◽  
Theoretical Approach ◽  
Material Properties ◽  
Beam Cross Section ◽  
European Standard ◽  
Fatigue Assessment ◽  
Concrete Members ◽  
Damage Structure ◽  
T Beam

Fatigue and fatigue damage leads to a change in material properties that can lead to the element failures. Generally, it is necessary to verify the influence of the fatigue effects on the concrete members according to European standard EC2, [1]. FRP materials have been possibly used for the fatigue damage structure rehabilitation. There we can apply the condition of the limit boundaries stress on concrete and limit force in FRP material theoretical approach. Fatigue assessment will be analyzed for T-beam cross section with reinforcement and strengthened FPR material in this paper.

scholarly journals A Theoretical Approach to Predict the Fatigue Life of Flexible Pipes

2012 ◽  
Vol 2012 ◽  
pp. 1-29 ◽  
Author(s):  
José Renato M. de Sousa ◽  
Fernando J. M. de Sousa ◽  
Marcos Q. de Siqueira ◽  
Luís V. S. Sagrilo ◽  
Carlos Alberto D. de Lemos
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Cross Section ◽  
Time Domain ◽  
Theoretical Approach ◽  
Flexible Pipe ◽  
Stress Effects ◽  
Flexible Pipes ◽  
Counting Methods ◽  
Mean Stresses

This paper focuses on a theoretical approach to access the fatigue life of flexible pipes. This methodology employs functions that convert forces and moments obtained in time-domain global analyses into stresses in their tensile armors. The stresses are then processed by well-known cycle counting methods, andS-Ncurves are used to evaluate the fatigue damage at several points in the pipe’s cross-section. Finally, Palmgren-Miner linear damage hypothesis is assumed in order to calculate the accumulated fatigue damage. A study on the fatigue life of a flexible pipe employing this methodology is presented. The main points addressed in the study are the influence of friction between layers, the effect of the annulus conditions, the importance of evaluating the fatigue life in various points of the pipe’s cross-section, and the effect of mean stresses. The results obtained suggest that the friction between layers and the annulus conditions strongly influences the fatigue life of flexible pipes. Moreover, mean stress effects are also significant, and at least half of the wires in each analyzed section of the pipe must be considered in a typical fatigue analysis.

On the Analysis of Damping in Elastic-plastic Inhomogeneous Beams

2021 ◽  
Vol 1046 ◽  
pp. 59-64
Author(s):  
Victor Iliev Rizov
Keyword(s):  
Cross Section ◽  
Material Properties ◽  
Analytical Approach ◽  
Strain Curve ◽  
Cyclic Stress ◽  
Beam Cross Section ◽  
Stress Strain Curve ◽  
Beam Structure ◽  
Elastic Plastic ◽  
Axial Forces

This paper describes an analytical approach for analyzing of the total damping energy for a continuously inhomogeneous elastic-plastic beam structure subjected to cyclic axial forces. The mechanical behaviour of the material is treated by using a cyclic stress-strain curve of the Ramberg-Osgood form. The beam cross-section is a rectangle. The material properties are distributed continuously along the height of the beam cross-section. The unit damping energy is integrated in the beam volume in order to derive the total damping energy. The analytical solution obtained is applied to carry-out a parametric study of the total damping energy in the beam structure.

Piezoelectric T-Beam Microactuators

2008 ◽  
Author(s):  
Hareesh K. R. Kommepalli ◽  
Andrew D. Hirsh ◽  
Christopher D. Rahn ◽  
Srinivas A. Tadigadapa
Keyword(s):  
Cross Section ◽  
Fabrication Process ◽  
Mems Fabrication ◽  
Out Of Plane ◽  
Cantilevered Beam ◽  
Piezoelectric Mems ◽  
The Cross ◽  
T Beam ◽  
Cross Section Geometry

This paper introduces a novel T-beam actuator fabricated by a piezoelectric MEMS fabrication process. ICP-RIE etching from the front and back of a bulk PZT chip is used to produce stair stepped structures through the thickness with complex inplane shapes. Masked electrode deposition creates active and passive regions in the PZT structure. With a T-shaped crosssection, and bottom and top flange and web electrodes, a cantilevered beam can bend in-plane and out-of-plane with bimorph actuation in both directions. One of these T-beam actuators is fabricated and experimentally tested. An experimentally validated model predicts that the cross-section geometry can be optimized to produce higher displacement and blocking force.

Probabilistic Fatigue Assessment of a Mooring Line Based on Station-Keeping Trials in Ice

2021 ◽  
Author(s):  
Chana Sinsabvarodom ◽  
Bernt J. Leira ◽  
Wei Chai ◽  
Arvid Naess
Keyword(s):  
Fatigue Damage ◽  
Probabilistic Models ◽  
Full Scale ◽  
Mooring Line ◽  
Stress Range ◽  
Station Keeping ◽  
Probability Models ◽  
Line System ◽  
Fatigue Assessment ◽  
Rainflow Counting

Abstract The intention of this work is to perform a probabilistic fatigue assessment of a mooring line due to loads associated with the station-keeping of a ship in ice. In March 2017, the company Equinor (Statoil) conducted full-scale tests by means of station-keeping trials (SKT) in drifting ice in the Bay of Bothnia. The vessel Magne Viking was employed in order to represent a supply vessel equipped with a mooring line system, and the realtime loading during the full-scale measurement was recorded. The second vessel Tor Viking was serving as an ice breaker in order to maintain the physical ice management activities with different ice-breaking schemes, i.e. square updrift pattern, round circle pattern, circular updrift pattern and linear updrift pattern. The fatigue degradation corresponding to these different patterns were investigated. The peaks and valleys of the mooring tension are determined using the min peak prominence method. For the purpose of probabilistic fatigue assessment, the Rainflow-counting algorithm is applied to estimate the mooring stress range. Fatigue assessment based both on Rainflow counting and fitted probabilistic models were performed. For the latter, the stress range distributions from the observed data of mooring loads are fitted to various probability models in order to estimate the fatigue damage. It is found that the stress ranges represented by application of the Weibull distribution for the probabilistic fatigue approach provides results of the fatigue damage most similar to the Rainflow counting approach. Among the different scenarios of Ice management schemes, the circular updrift pattern provides the lowest magnitude of the fatigue degradation.

Formation of given field distribution in laser-beam cross section

1984 ◽  
Vol 27 (5) ◽  
pp. 411-413
Author(s):  
V. B. Korshikov ◽  
P. R. Lakhno ◽  
V. N. Rozhdestvin
Keyword(s):  
Laser Beam ◽  
Cross Section ◽  
Field Distribution ◽  
Beam Cross Section

Fatigue damage in bending of reinforced concrete frames using non-destructive tests for dynamic strength of the cylinder

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dragan D. Milašinović ◽  
Aleksandar Landović ◽  
Danica Goleš
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Damage ◽  
Cross Section ◽  
Modal Parameters ◽  
The Finite Element Method ◽  
Concrete Frames ◽  
Content Type ◽  
Non Destructive

PurposeThe purpose of this paper is to contribute to the solution of the fatigue damage problem of reinforced concrete frames in bending.Design/methodology/approachThe problem of fatigue damage is formulated based on the rheological–dynamical analogy, including a scalar damage variable to address the reduction of stiffness in strain softening. The modal analysis is used by the finite element method for the determination of modal parameters and resonance stability of the selected frame cross-section. The objectivity of the presented method is verified by numerical examples, predicting the ductility in bending of the frame whose basic mechanical properties were obtained by non-destructive testing systems.FindingsThe modal analysis in the frame of the finite element method is suitable for the determination of modal parameters and resonance stability of the selected frame cross-section. It is recommended that the modulus of elasticity be determined by non-destructive methods, e.g. from the acoustic response.Originality/valueThe paper presents a novel method of solving the ductility in bending taking into account both the creep coefficient and the aging coefficient. The rheological-dynamical analogy (RDA) method uses the resonant method to find material properties. The characterization of the structural damping via the damping ratio is original and effective.

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