scholarly journals A Moving Interface Finite Element Formulation to Predict Dynamic Edge Debonding in FRP-Strengthened Concrete Beams in Service Conditions

Fibers ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 42 ◽  
Author(s):  
Marco Francesco Funari ◽  
Saverio Spadea ◽  
Francesco Fabbrocino ◽  
Raimondo Luciano
Keyword(s):  
Finite Element ◽  
Concrete Beams ◽  
Load Condition ◽  
Adhesive Layer ◽  
Element Formulation ◽  
Interface Elements ◽  
Moving Interface ◽  
Cohesive Interfaces ◽  
Fibre Reinforced Polymer ◽  
Frp Strengthening

A new methodology to predict interfacial debonding phenomena in fibre-reinforced polymer (FRP) concrete beams in the serviceability load condition is proposed. The numerical model, formulated in a bi-dimensional context, incorporates moving mesh modelling of cohesive interfaces in order to simulate crack initiation and propagation between concrete and FRP strengthening. Interface elements are used to predict debonding mechanisms. The concrete beams, as well as the FRP strengthening, follow a one-dimensional model based on Timoshenko beam kinematics theory, whereas the adhesive layer is simulated by using a 2D plane stress formulation. The implementation, which is developed in the framework of a finite element (FE) formulation, as well as the solution scheme and a numerical case study are presented.

Experimental testing and finite element modeling on continuous concrete beams reinforced with fibre reinforced polymer bars and stirrups

2013 ◽  
Vol 40 (11) ◽  
pp. 1091-1102 ◽  
Author(s):  
Mostafa El-Mogy ◽  
Amr El-Ragaby ◽  
Ehab El-Salakawy
Keyword(s):  
Finite Element ◽  
Concrete Beams ◽  
Experimental Testing ◽  
Steel Corrosion ◽  
Element Model ◽  
Elastic Behaviour ◽  
Transverse Reinforcement ◽  
Moment Redistribution ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Continuous concrete beams are common elements in structures such as parking garages and overpasses, which might be exposed to extreme weather. Using the non-corrodible fibre reinforced polymer (FRP) bars is a viable alternative to avoid steel corrosion problems. Due to the linear-elastic behaviour of FRP materials, the possibility of moment redistribution in FRP-reinforced beams is questionable. In this paper, the experimental results of ten full-scale continuous concrete beams are summarized followed by a finite element parametric study using ANSYS software. Steel, glass fibre reinforced polymer, and carbon fibre reinforced polymer bars were used in different combinations as longitudinal and transverse reinforcement. The main investigated parameters were the ratio and type of longitudinal and transverse reinforcement. Results showed that moment redistribution in such beams is possible if the reinforcement configuration is chosen properly. The developed finite element model predicted the response of tested beams with a reasonable degree of accuracy and was used to expand the range of investigated parameters.

Mechanics of fibre-reinforced polymer - concrete interfaces

2007 ◽  
Vol 34 (3) ◽  
pp. 367-377 ◽  
Author(s):  
U A Ebead ◽  
K W Neale
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Concrete Block ◽  
Polymer Concrete ◽  
Element Analysis ◽  
Interface Elements ◽  
Frp Composite ◽  
Reinforced Polymer ◽  
Interfacial Behaviour ◽  
Fibre Reinforced Polymer

A finite element model is developed for analyzing the interfacial behaviour for fibre-reinforced polymer (FRP) laminates externally bonded to concrete prisms and subjected to direct shear. The element sizes of the FRP, adhesive, and concrete at the interface were chosen to be very small (0.25–0.5 mm) so that the debonding behaviour could be properly captured. The behaviour at the interface between the FRP composite and the concrete is modelled using truss elements connecting the FRP laminate to the concrete block. The truss elements incorporate a nonlinear bond stress-slip relationship controlled by several parameters related to the characteristics of the FRP composite, adhesive, and concrete. Results are given in terms of the load capacity of the joint and the stress and strain distributions in the FRP, at the interface, and in the concrete. In addition, the transfer lengths, as well as the force transfer between the FRP laminate and the concrete block, are investigated. Comparisons between the finite element results and available experimental data are presented.Key words: nonlinear finite element analysis, FRP-to-concrete bonded joints, interface elements, debonding, interfacial behaviour, transfer lengths.

Some Remarks on the Numerical Modelling of Localized Failure

2013 ◽  
Vol 535-536 ◽  
pp. 147-151 ◽  
Author(s):  
Otto T. Bruhns
Keyword(s):  
Finite Element ◽  
Crack Path ◽  
Three Dimensional ◽  
Predictive Ability ◽  
Strong Discontinuity ◽  
Element Formulation ◽  
Material Failure ◽  
Interface Elements ◽  
Continuous Crack ◽  
Positive Feature

An efficient numerical framework suitable for three-dimensional analyses of brittle material failure is presented. The proposed model is based on an (embedded) Strong Discontinuity Approach (SDA). Hence, the deformation mapping is elementwise additively decomposed into a conforming, continuous part and an enhanced part associated with the kinematics induced by material failure. To overcome locking effects and to provide a continuous crack path approximation, the approach is extended and combined with advantages known from classical interface elements. More precisely, several discontinuities each of them being parallel to a facet of the respective finite element are considered. By doing so, crack path continuity is automatically fulfilled and no tracking algorithm is necessary. However, though this idea is similar to that of interface elements, the novel SDA is strictly local (finite element level) and thus, it does not require any modification of the global data structure, e.g., no duplication of nodes. An additional positive feature of the advocated finite element formulation is that it leads to a symmetric tangent matrix. It is shown that several simultaneously active discontinuities in each finite element are required to capture highly localized material failure. The performance and predictive ability of the model are demonstrated by means of two benchmark examples.

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