Modeling and Simulation of the Failure and Stiffness Degradation of a Graphite Epoxy in a Three Point Bending Test

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
E. H. Irhirane ◽  
M. Abousaleh ◽  
J. Echaabi ◽  
M. Hattabi ◽  
A. Saouab ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Experimental Approach ◽  
Failure Modes ◽  
Failure Criteria ◽  
Bending Test ◽  
Geometrical Parameters ◽  
Three Point Bending ◽  
Stiffness Reduction ◽  
Biaxial Tests ◽  
Macroscopic Failure

The use of composite materials with continuous fibers in the aeronautic and aerospace industries requires reliable and precise methods for the prediction of failure. Predicting failure stresses and failure modes in composite laminates is very difficult. The choice between failure criteria is complex, and there is a lack of experimental study to validate the result obtained partly because the biaxial tests are still difficult to perform. This work employs a mixed methodology based on a theoretical and an experimental approach to develop a procedure for the choice and the validation of the failure criterion. The comparison is concerned not only with the macroscopic failure but also with the succession of the failure, the failure mode, and the effect of the geometrical parameters of the test specimen. The most general failure criteria are tested by using two approaches of the stiffness reduction. A finite element code has been elaborated within our laboratory for postfailure treatment. The numerical simulation results are compared with the experimental ones and permit us to make a conclusion on the validity of the failure criteria used.

Nonlinear modeling of the failure of a graphite epoxy under a three-point bending test

2019 ◽  
Vol 28 (2) ◽  
pp. 119-139
Author(s):  
Youssef Benbouras ◽  
Mouad Bellahkim ◽  
Aziz Maziri ◽  
Elhassan Mallil ◽  
Jamal Echaabi
Keyword(s):  
Experimental Study ◽  
Analytical Modeling ◽  
Nonlinear Modeling ◽  
Laminated Composite ◽  
Failure Criteria ◽  
Anisotropic Materials ◽  
Bending Test ◽  
Geometrical Parameters ◽  
Three Point Bending ◽  
Biaxial Tests

The application of modeling theories and the choice of failure criteria are difficult in part because they are too varied and must be validated by biaxial tests, which are expensive to be performed. This article is devoted to the nonlinear modeling and failure criteria which are employed in the design and analysis of anisotropic materials. Indeed, in this work, a study of the macroscopic and microscopic behavior of a graphite epoxy under a three-point bending test is conducted, and the successive failures are also predicted. Experimentally, the damage progression and the effect of geometrical parameters are followed and identified in detail. The analytical modeling is based on a recently developed approximation for isotropic materials. This approximation is also valid for the studied quasi-isotropic laminated composite. A software program has been elaborated for the application of the most general failure criteria. The results obtained by this analytical modeling show a good correlation with those of the experimental study.

scholarly journals A review and application of the failure criteria on a graphite epoxy under three-point bending test

2019 ◽  
Vol 286 ◽  
pp. 02007
Author(s):  
Y. Benbouras ◽  
M. Bellahkim ◽  
A. Maziri ◽  
E. Mallil ◽  
J. Echaabi
Keyword(s):  
Experimental Study ◽  
Analytical Modeling ◽  
Failure Criteria ◽  
Bending Test ◽  
Three Point Bending ◽  
Biaxial Tests ◽  
Software Program

The application of failure criteria are difficult partly because they are too various and must be validated by biaxial tests, which are expensive to be achieved. In this work, an analytical modeling based on a software program has been elaborated for application of the most general failure criteria and prediction of successive failure. Finally, the results obtained by this analytical modeling show a good correlation with those carried out by experimental study.

An Experimental Study of Nonlinear Behavior of Graphite/Epoxy Laminate under a Three-Point Bending Test

2021 ◽  
Vol 900 ◽  
pp. 9-15
Author(s):  
Mouad Bellahkim ◽  
Youssef Benbouras ◽  
Aziz Maziri ◽  
El Hassan Mallil ◽  
Jamal Echaabi
Keyword(s):  
Experimental Study ◽  
Failure Modes ◽  
Nonlinear Behavior ◽  
Bending Test ◽  
Three Point Bending ◽  
Digital Microscope ◽  
Layer Orientation ◽  
Bending Behavior ◽  
The Relationship ◽  
Geometrical Dimensions

In this work, an attempt has been made to study the experimental of behavior for carbon/epoxy woven laminates under a three-point bending test by varying the support span and the geometrical dimensions of the specimens. Two principles stacking sequences are studied ([45 / 0]2s & [90 / 0]6 ) to observe the effect of the layer orientation in the failure modes. This study has allowed us to confirm the relationship between the bending behavior of the specimens and the span-to-thickness ratio (l/h). Finally, a digital microscope was selected in order to characterize the succession of the failure and the failure modes, mainly the delamination damage.

scholarly journals Stiffness Reduction of Composite Laminates under Combined Cyclic Stresses

2001 ◽  
Vol 10 (3) ◽  
pp. 096369350101000 ◽  
Author(s):  
T. P. Philippidis ◽  
A. P. Vassilopoulos
Keyword(s):  
Normal Stress ◽  
Composite Laminates ◽  
Failure Modes ◽  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Fibre Direction ◽  
Cyclic Stresses ◽  
Stiffness Reduction ◽  
Stress States ◽  
Modulus Reduction

Stiffness reduction due to fatigue of a [0/(±45)2/0]T Glass/Polyester (GRP) laminate under combined cyclic stress is investigated in this experimental study. Stress states combining all three components of in-plane stress tensor are induced by uniaxially testing specimens cut off-axis at various angles from the principal material coordinate system. Modulus reduction is related to the various failure modes exhibited under different states of combined stress. It is verified that shear and transverse normal stress induce more severe stiffness degradation compared to stress states where normal stress in the main fibre direction is dominant. For every loading condition and stress state, it is observed in general that stiffness decrease is more pronounced under lower stress levels than these inducing low cycle fatigue.

Experimental and numerical investigation of fatigue damage accumulation in composite laminates

2015 ◽  
Vol 26 (6) ◽  
pp. 840-858 ◽  
Author(s):  
Soran Hassanifard ◽  
Mohsen Feyzi
Keyword(s):  
Fatigue Life ◽  
Composite Laminates ◽  
Failure Modes ◽  
Three Dimensional ◽  
Load Ratio ◽  
Element Model ◽  
Failure Criteria ◽  
Damage Parameter ◽  
Fatigue Damage Accumulation ◽  
Three Dimensional Finite Element

In this study, a three-dimensional finite element model was developed to predict the fatigue life of composite bolted joints. In this model, progressive damage theory was used. The fatigue characterization was based on Hashin’s failure criteria which recognize the failure modes. To decrease the number of unidirectional tests, the effects of load ratio were considered based on Kawai’s criterion. A modified form of Miner’s rule was proposed to calculate the damage parameter. This equation corrected the effects of the fatigue failure cycles and included the effects of different load ratios. Also, this model could decrease the overestimation of the fatigue life predictions. All of the formulations were combined and used in a step-by-step solution. In this respect, a new iterative algorithm was developed so that at each step of solution, the material properties of all failed layers of each element were reduced according to the failure mode and sudden degradation rules. The estimated fatigue life was compared to the experimental data, and an excellent correlation between the results was observed. This model could monitor the damage propagation in fabricated joints.

scholarly journals An extended invariant approach to laminate failure of fibre-reinforced polymer structures

2022 ◽  
pp. 1-24
Author(s):  
G. Corrado ◽  
A. Arteiro ◽  
A.T. Marques ◽  
J. Reinoso ◽  
F. Daoud ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Failure Modes ◽  
Three Dimensional ◽  
Failure Criteria ◽  
Design Tool ◽  
Advanced Composite Materials ◽  
Failure Envelopes ◽  
Out Of Plane ◽  
Stress States

Abstract This paper presents the extension and validation of omni-failure envelopes for first-ply failure (FPF) and last-ply failure (LPF) analysis of advanced composite materials under general three-dimensional (3D) stress states. Phenomenological failure criteria based on invariant structural tensors are implemented to address failure events in multidirectional laminates using the “omni strain failure envelope” concept. This concept enables the generation of safe predictions of FPF and LPF of composite laminates, providing reliable and fast laminate failure indications that can be particularly useful as a design tool for conceptual and preliminary design of composite structures. The proposed extended omni strain failure envelopes allow not only identification of the controlling plies for FPF and LPF, but also of the controlling failure modes. FPF/LPF surfaces for general 3D stress states can be obtained using only the material properties extracted from the unidirectional (UD) material, and can predict membrane FPF or LPF of any laminate independently of lay-up, while considering the effect of out-of-plane stresses. The predictions of the LPF envelopes and surfaces are compared with experimental data on multidirectional laminates from the first and second World-Wide Failure Exercise (WWFE), showing a satisfactory agreement and validating the conservative character of omni-failure envelopes also in the presence of high levels of triaxiality.

scholarly journals Interaction between Edge-Crack and Aggregate in Silicate-Based Composite

2017 ◽  
Vol 17 (2) ◽  
pp. 59-64
Author(s):  
Lucie Malíková ◽  
Jan Klusák
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Edge Crack ◽  
Matrix Material ◽  
Interfacial Transition Zone ◽  
Bending Test ◽  
Geometrical Parameters ◽  
The Finite Element Method ◽  
Three Point Bending

Abstract The paper deals with investigation of the interaction between an edge-crack and an aggregate in a silicate-based composite, because adding of aggregates into basic matrix material can improve the fracture mechanical properties of the material significantly. In this work, the three-point-bending test is modelled by means of the finite element method and the dependences of fracture parameters on various material and geometrical parameters of the aggregate and the interfacial transition zone are studied. The results are discussed thoroughly.

scholarly journals Progressive Damage Numerical Modelling and Simulation of Aircraft Composite Bolted Joints Bearing Response

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5606
Author(s):  
Guoqiang Gao ◽  
Luling An ◽  
Ioannis K. Giannopoulos ◽  
Ning Han ◽  
Ende Ge ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Composite Laminates ◽  
Composite Structures ◽  
Failure Modes ◽  
Composite Plates ◽  
Failure Criteria ◽  
Bolted Joints ◽  
Progressive Damage ◽  
User Input ◽  
Product Cycles

Finite element numerical progressive damage modelling and simulations applied to the strength prediction of airframe bolted joints on composite laminates can lead to shorter and more efficient product cycles in terms of design, analysis and certification, while benefiting the economic manufacturing of composite structures. In the study herein, experimental bolted joint bearing tests were carried out to study the strength and failure modes of fastened composite plates under static tensile loads. The experimental results were subsequently benchmarked against various progressive damage numerical modelling simulations where the effects of different failure criteria, damage variables and subroutines were considered. Evidence was produced that indicated that both the accuracy of the simulation results and the speed of calculation were affected by the choice of user input and numerical scheme.

Finite Element and Experimental Study of the Fiber-Reinforced Composite Laminates under Low-Velocity Impact

2013 ◽  
Vol 535-536 ◽  
pp. 505-508
Author(s):  
Han Yang Liu ◽  
Xin Ming Qiu ◽  
Deng Yu Zhang ◽  
Yu Huai He ◽  
Jin Juan Fan
Keyword(s):  
Composite Laminates ◽  
Failure Modes ◽  
Failure Criteria ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Level ◽  
Nondestructive Examination ◽  
The Matrix ◽  
The Impact

Experimental and numerical studies of the 2D woven composite laminates under low-velocity impact with different energy are discussed in this paper. The traditional Hashin failure criteria are improved to cover the failure modes of fiber rupture and delamination. It is found that the damage level depend on the impact energy. The matrix deformation is the main reason of delamination. The simulating results are in good agreement with the experimental phenomenon observed by nondestructive examination (ultrasonic C scanning) and cross-section examination

scholarly journals Three-Point Bending Test for Three Different Bolt Diameters

2019 ◽  
Vol 4 (1) ◽  
pp. 41-53
Author(s):  
Nor Jihan Abd Malek ◽  
◽  
Sadiq Azizi Othman ◽  
Keyword(s):  
Failure Modes ◽  
Bending Strength ◽  
Construction Materials ◽  
Bending Test ◽  
Structural Element ◽  
Yield Model ◽  
Three Point Bending ◽  
Percentage Difference ◽  
R Value ◽  
Materials Used

Timber is one of the oldest materials used as main structural element prior concrete and steel which have greater ability to sustain load. The greater demand for timber as construction materials, the wood engineering introduced a new timber type called Engineered Wood Product (EWP). The crucial problem in the timber structure which focuses on the structural timber connection. The load-carrying capacity of the timber connection and the failure modes can be determined according to the European Yield Model (EYM). Three-point bending test was used to determine yield moment of the fastener, My, bolt bending strength, Fyb and average R-value for three selected different bolt diameters which are 12, 16 and 20 mm. The results were obtained for comparing between three bolt diameters with F2%, F5% and Fmax respectively. The F2% for 12, 16 and 20 mm yield moment of the fastener, My was obtained 596.4, 1631.5 and 4650 kNmm accordingly while for bolt bending strength, Fyb was 2.1, 2.4 and 3.5 kN correspondingly. The F5% for 12, 16 and 20 mm yield moment of the fastener, My was obtained 631.1, 1668.3 and 4895.6 kNmm accordingly while for bolt bending strength, Fyb was 2.2, 2.4 and 3.7 kN correspondingly. The Fmax for 12, 16 and 20 mm yield moment of the fastener, My was obtained 828.2, 2290.8 and 6545.4 kNmm accordingly while for bolt bending strength, Fyb was 2.9, 3.4 and 4.9 kN correspondingly. The average R-value for 12, 16 and 20 mm bolt diameter was 0.50214, 0.42768 and 0.42038 individually. In conclusion, the percentage difference for F2% bolt bending strength, Fyb between 12 and 16 mm has raised about 14% whereas 16 and 20 mm has shown 46% increased.

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