The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
J G Teng - One of the best experts on this subject based on the ideXlab platform.
-
Finite element modelling of Debonding failures in steel beams flexurally strengthened with CFRP laminates
Engineering Structures, 2015Co-Authors: J G Teng, Dilum Fernando, Tao YuAbstract:A steel beam may be strengthened in flexure by bonding a carbon fibre-reinforced polymer (CFRP) plate to the tension face. Such a beam may fail by Debonding of the CFRP plate that initiates at one of the plate ends (i.e. plate end Debonding) or by Debonding that initiates at a local damage (e.g. a crack or concentrated yielding) away from the plate ends (intermediate Debonding). This paper presents the first finite element (FE) approach that is capable of accurate predictions of such Debonding failures, with particular attention to plate-end Debonding. In the proposed FE approach, a mixed-mode cohesive law is employed to depict interfacial behaviour under a combination of normal stresses (i.e. mode-I loading) and shear stresses (i.e. mode-II loading); the interfacial behaviour under pure mode-I loading or pure mode-II loading is represented by bi-linear traction–separation models. Damage initiation is defined using a quadratic strength criterion, and damage evolution is defined using a linear fracture energy-based criterion. Detailed FE models of steel beams tested by previous researchers are presented, and their predictions are shown to be in close agreement with the test results. Using the proposed FE approach, the behaviour of CFRP-strengthened steel beams is examined, indicating that: (1) if the failure is governed by plate end Debonding, the use of a CFRP plate with a higher elastic modulus and/or a larger thickness may lead to a lower ultimate load because plate end Debonding may then occur earlier; (2) plate end Debonding is more likely to occur when a short CFRP plate is used, as is commonly expected; and (3) the failure mode may change to intermediate Debonding or other failure modes such as compression flange buckling if a longer plate is used.
-
Finite element modelling of Debonding failures in steel beams flexurally strengthened with CFRP laminates
Pergamon Press, 2015Co-Authors: J G Teng, Fernando D, Yu TAbstract:A steel beam may be strengthened in flexure by bonding a carbon fibre-reinforced polymer (CFRP) plate to the tension face. Such a beam may fail by Debonding of the CFRP plate that initiates at one of the plate ends (i.e. plate end Debonding) or by Debonding that initiates at a local damage (e.g. a crack or concentrated yielding) away from the plate ends (intermediate Debonding). This paper presents the first finite element (FE) approach that is capable of accurate predictions of such Debonding failures, with particular attention to plate-end Debonding. In the proposed FE approach, a mixed-mode cohesive law is employed to depict interfacial behaviour under a combination of normal stresses (i.e. mode-I loading) and shear stresses (i.e. mode-II loading); the interfacial behaviour under pure mode-I loading or pure mode-II loading is represented by bi-linear traction-separation models. Damage initiation is defined using a quadratic strength criterion, and damage evolution is defined using a linear fracture energy-based criterion. Detailed FE models of steel beams tested by previous researchers are presented, and their predictions are shown to be in close agreement with the test results. Using the proposed FE approach, the behaviour of CFRP-strengthened steel beams is examined, indicating that: (1) if the failure is governed by plate end Debonding, the use of a CFRP plate with a higher elastic modulus and/or a larger thickness may lead to a lower ultimate load because plate end Debonding may then occur earlier; (2) plate end Debonding is more likely to occur when a short CFRP plate is used, as is commonly expected; and (3) the failure mode may change to intermediate Debonding or other failure modes such as compression flange buckling if a longer plate is used.Department of Civil and Environmental Engineerin
-
Finite element modelling of Debonding failures in steel beams flexurally strengthened with CFRP laminates
'Elsevier BV', 2015Co-Authors: J G Teng, Fernando D, Yu TAbstract:A steel beam may be strengthened in flexure by bonding a carbon fibre-reinforced polymer (CFRP) plate to the tension face. Such a beam may fail by Debonding of the CFRP plate that initiates at one of the plate ends (i.e. plate end Debonding) or by Debonding that initiates at a local damage (e.g. a crack or concentrated yielding) away from the plate ends (intermediate Debonding). This paper presents the first finite element (FE) approach that is capable of accurate predictions of such Debonding failures, with particular attention to plate-end Debonding. In the proposed FE approach, a mixed-mode cohesive law is employed to depict interfacial behaviour under a combination of normal stresses (i.e. mode-I loading) and shear stresses (i.e. mode-II loading); the interfacial behaviour under pure mode-I loading or pure mode-II loading is represented by bi-linear traction-separation models. Damage initiation is defined using a quadratic strength criterion, and damage evolution is defined using a linear fracture energy-based criterion. Detailed FE models of steel beams tested by previous researchers are presented, and their predictions are shown to be in close agreement with the test results. Using the proposed FE approach, the behaviour of CFRP-strengthened steel beams is examined, indicating that: (1) if the failure is governed by plate end Debonding, the use of a CFRP plate with a higher elastic modulus and/or a larger thickness may lead to a lower ultimate load because plate end Debonding may then occur earlier; (2) plate end Debonding is more likely to occur when a short CFRP plate is used, as is commonly expected; and (3) the failure mode may change to intermediate Debonding or other failure modes such as compression flange buckling if a longer plate is used.Department of Civil and Environmental Engineering2014-2015 > Academic research: refereed > Publication in refereed journa
-
Plate end Debonding failure loads of FRP-or steel-plated RC beams
2008Co-Authors: Jian Yao, J G TengAbstract:Plate end Debonding failure loads of RC beams strengthened in flexure by bonding an FRP or steel plate to the tension face were investigated in detail.Based on studies of the controlling parameters,the available test data and comparisons of these test data with existing Debonding strength models,a simple,rationally-based predictive model for plate end Debonding failure loads was presented.In this model,pure flexural Debonding for a plate end located in a pure bending region and pure shear Debonding for a plate end located in a high-shear zero(or low)-moment region are first dealt with.The general case of a plate end under the combined action of shear and bending is treated as the interaction of these two extreme conditions.The proposed model is shown to be accurate through comparisons with available test results.The model relates the Debonding failure load to the shear capacity of the beam and a number of well-defined parameters,and can be easily incorporated in future design codes and guidelines,and may be used in practical applications.
-
plate end Debonding in frp plated rc beams ii strength model
Engineering Structures, 2007Co-Authors: J G TengAbstract:RC beams strengthened in flexure by bonding an FRP or steel plate to the tension face can fail by Debonding at or near the plate end in a number of different modes. This paper presents a simple, rationally-based predictive model for such plate end Debonding failures. In this model, pure flexural Debonding for a plate end located in a pure bending region and pure shear Debonding for a plate end located in a high-shear zero (or low)-moment region are first dealt with. The general case of a plate end under the combined action of shear and bending is treated as the interaction of these two extreme conditions. The proposed model is shown to be accurate through comparisons with available test results. The model relates the Debonding failure load to the shear capacity of the beam and a number of well-defined parameters, and can be easily incorporated in any national or international design codes and guidelines.
Masoud Motavalli - One of the best experts on this subject based on the ideXlab platform.
-
Debonding failure modes of flexural frp strengthened rc beams
Composites Part B-engineering, 2008Co-Authors: Mohammad Reza Aram, Christoph Czaderski, Masoud MotavalliAbstract:Abstract In this paper, different types of Debonding failure modes are described. Then, experimental results of four-point bending tests on FRP strengthened RC beams are presented and Debonding failure mechanisms of strengthened beams are investigated using analytical and finite element solutions. Reasonable results could be obtained for modelling of Debonding failure load of tested beams. Existing international codes and guidelines from organizations such as ACI, fib , ISIS, JSCE, SIA, TR55, etc. are presented and compared with the results from the experiments and calculations. A discrepancy of up to 250% was seen between different codes and guidelines for predicting the Debonding load. Furthermore, a new recommendation for Debonding control is given.
Tomasz Sadowski - One of the best experts on this subject based on the ideXlab platform.
-
influence of skin core Debonding on free vibration behavior of foam and honeycomb cored sandwich plates
International Journal of Non-linear Mechanics, 2010Co-Authors: Vyacheslav N. Burlayenko, Tomasz SadowskiAbstract:The dynamic behavior of partially delaminated at the skin/core interface sandwich plates with flexible cores is studied. The commercial finite element code ABAQUS is used to calculate natural frequencies and mode shapes of the sandwich plates containing a Debonding zone. The influence of the Debonding size, Debonding location and types of Debonding on the modal parameters of damaged sandwich plates with various boundary conditions is investigated. The results of dynamic analysis illustrated that they can be useful for analyzing practical problems related to the non-destructive damage detection of partially debonded sandwich plates.
Philippe H Geubelle - One of the best experts on this subject based on the ideXlab platform.
-
the uniaxial tension of particulate composite materials with nonlinear interface Debonding
International Journal of Solids and Structures, 2007Co-Authors: Henry Tan, Yonggang Huang, C Liu, G. Ravichandran, H M Inglis, Philippe H GeubelleAbstract:Debonding of particle/matrix interfaces can significantly affect the macroscopic behavior of composite material. We have used a nonlinear cohesive law for particle/matrix interfaces to study interface Debonding and its effect on particulate composite materials subject to uniaxial tension. The dilute solution shows that, at a fixed particle volume fraction, small particles lead to hardening behavior of the composite while large particles yield softening behavior. Interface Debonding of large particles is unstable since the interface opening (and sliding) displacement(s) may have a sudden jump as the applied strain increases, which is called the catastrophic Debonding. A simple estimate is given for the critical particle radius that separates the hardening and softening behavior of the composite.
-
the mori tanaka method for composite materials with nonlinear interface Debonding
International Journal of Plasticity, 2005Co-Authors: Henry Tan, Yonggang Huang, C Liu, Philippe H GeubelleAbstract:We have used the Mori–Tanaka method to study the effect of nonlinear interface Debonding on the constitutive behavior of composite material with high particle volume fraction. The interface Debonding is characterized by a nonlinear cohesive law determined from the fracture test of the high explosive PBX 9501. Using the example of the composite material with spherical particles subject to hydrostatic tension, we show that the particle size has an important effect on the behavior of the composite material, namely hardening for small particles and softening for large particles. The critical particle size that separates the hardening and softening behavior of the composite material is determined. For the composite material with large particles, the particle/matrix interface may undergo catastrophic Debonding, i.e., sudden, dynamic Debonding even under static load. The energy release during catastrophic Debonding can be very large, thus may trigger the reaction or detonation of high explosives. For the high explosive PBX 9501, the energy release due to catastrophic Debonding of coarse (large)
-
the mori tanaka method for composite materials with nonlinear interface Debonding
International Journal of Plasticity, 2005Co-Authors: Henry Tan, Yonggang Huang, C Liu, Philippe H GeubelleAbstract:Abstract We have used the Mori–Tanaka method to study the effect of nonlinear interface Debonding on the constitutive behavior of composite material with high particle volume fraction. The interface Debonding is characterized by a nonlinear cohesive law determined from the fracture test of the high explosive PBX 9501. Using the example of the composite material with spherical particles subject to hydrostatic tension, we show that the particle size has an important effect on the behavior of the composite material, namely hardening for small particles and softening for large particles. The critical particle size that separates the hardening and softening behavior of the composite material is determined. For the composite material with large particles, the particle/matrix interface may undergo catastrophic Debonding, i.e., sudden, dynamic Debonding even under static load. The energy release during catastrophic Debonding can be very large, thus may trigger the reaction or detonation of high explosives. For the high explosive PBX 9501, the energy release due to catastrophic Debonding of coarse (large) particles is equivalent to the free drop of the high explosive from a height of 110 m. This value become much higher, 455 m, once the Debonding of fine (small) particle is accounted for.
Oded Rabinovitch - One of the best experts on this subject based on the ideXlab platform.
-
modeling of interfacial Debonding propagation in sandwich panels
International Journal of Solids and Structures, 2017Co-Authors: Itay Odessa, Y Frostig, Oded RabinovitchAbstract:Abstract The paper presents a nonlinear model for the analysis of the process of Debonding between a face sheet and the core in sandwich panels. The model incorporates the Extended High-Order Sandwich Panel Theory with a cohesive interface modeling of the crack nucleation and propagation at the interface between a face sheet and the core. The derivation of the model combines the first order shear deformation kinematic assumptions for the face sheets with the high order small deformations kinematic assumptions that include out of plane compressibility for the core. The cohesive interfaces combine the components of the sandwich panel together and introduce the nonlinearity and the interfacial failure process into the model by means of nonlinear traction-separation laws. The properties of the cohesive interface are calibrated and the proposed model is validated through comparison with experimental results taken from the literature. Two cases that include the Double Cantilever Beam (DCB) and the Cracked Sandwich Beam (CSB) specimens are considered. In the DCB test, the panel is subjected to a global mode I loading, while in the CSB test is subjected to a loading scheme that yields a global mode II. On the local scale, a mixed mode is observed in the two tests. For the CSB case, contact constraints between the debonded face sheet and the core are also included. The comparison of the analytical results with the experimental ones focuses on the initial linear response, the nucleation of the interfacial Debonding crack, and the propagation of the crack. The comparison validates the model and explores the deobnding failure process in sandwich panels.
-
Impact of thermal loads on interfacial Debonding in FRP strengthened beams
International Journal of Solids and Structures, 2010Co-Authors: Oded RabinovitchAbstract:The effect of thermal loads on the Debonding mechanisms in beams strengthened with externally bonded composite materials is analytically investigated. The analytical approach adopts a high-order stress analysis model and a fracture mechanics model that uses the concept of the energy release rate through the thermo-mechanical form of the J-integral. The two models are combined to synthesize the relation between the energy release rate, the mechanical loads, the thermal loads, and the interfacial crack length simulating the thermo-mechanical Debonding process. The model is supported through comparison with experimental results taken from the literature. The comparison quantifies and explains various phenomena observed in the experiments and mainly the non-monotonic dependency of the Debonding failure load on the temperature. The impact of the temperature on the interfacial stresses and on the stability of the Debonding process is also studied. Finally, the effect of an uniform thermal load on the Debonding behavior of a strengthened beam is studied revealing the impact of the thermal load on the Debonding stability and strength characteristics.
