The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Bel Abbes Bachir Bouiadjra - One of the best experts on this subject based on the ideXlab platform.

  • effect of the patch length on the effectiveness of one sided bonded Composite Repair for aluminum panels
    International Journal of Adhesion and Adhesives, 2018
    Co-Authors: A Albedah, Bel Abbes Bachir Bouiadjra, Sohail Khan M A Mohammed, F Benyahia
    Abstract:

    Abstract This study analyzes the effect of the patch length the Repair performance of bonded Composite Repair. Experimental and numerical approaches are used. In the experimental part of the study, fatigue tests with a constant amplitude were performed on notched specimens of 2024 T3 and 7075 T6 aeronautical aluminum alloys. Two stress ratios of R = 0 and R=0.1 were applied. The value of the patch length was varied to highlight its effect on the fatigue life. In the numerical part, the stress intensity factor and adhesive stresses were computed for different sizes of the patch length. The experimental results show that the fatigue life of Repaired plates is significantly reduced with increases in patch length irrespective of the type of aluminum alloy and the stress ratio. The numerical results show that the stress intensity factor increases with increases in the patch length, and this is in agreement with the experimental results. This effect is explained by the presence of a secondary bending moment generated by the application of a single sided Composite patch.

  • experimental and numerical analysis of bonded Composite patch Repair in aluminum alloy 7075 t6
    Materials & Design, 2015
    Co-Authors: F Benyahia, Bel Abbes Bachir Bouiadjra, A Albedah, L Aminallah, Tahar Achour
    Abstract:

    Abstract In this study, the performances of aged bonded Composite Repair of aircraft structures have been evaluated by conducting experimental and numerical investigations. The accelerating aging of the patch was realized by immersion in water for 120 days. The performance of aged and non-aged bonded Composite patches in the Repair of cracked structures was evaluated. The experimental results showed that the fatigue life of the aircraft structures can be significantly improved with the patch Repair. The patch aging reduces the Repair performances because of the reduction of the Composite rigidity by humidity absorption. Numerical results show that the stress intensity factor at the crack tip is significantly reduced by the presence of the patch. The humidity absorption increases the stress intensity factor at the crack tip and decreases the adhesive stresses. Nevertheless, the Repair durability cannot be improved by the humidity absorption because it leads to a reduction of the mechanical resistance of the adhesive.

  • elliptical and circular bonded Composite Repair under mechanical and thermal loading in aircraft structures
    Materials Research-ibero-american Journal of Materials, 2014
    Co-Authors: F Benyahia, A Albedah, Bel Abbes Bachir Bouiadjra
    Abstract:

    In this study, the three-dimensional finite element method is used to achieve a comparison between the semi circular and semi elliptical patch Repairs in aircraft structures. The comparison was done by the analysis of : the mechanical and thermal stress intensity factors (SIF and TSIF) at the tip of Repaired crack and the distribution of the adhesive stresses for the two patch shapes. The obtained results show that the semi circular shape of the patch presents lower stress intensity factor at the crack tip, which is beneficial for the fatigue life and lower adhesives stresses, which is beneficial for the Repair durability. In addition the circular patch is subjected to less significant thermal residual stresses compared to the elliptical shapes.

  • effect of water absorption on the adhesive damage in bonded Composite Repair of aircraft structures
    Materials & Design, 2014
    Co-Authors: F Benyahia, Bel Abbes Bachir Bouiadjra, A Albedah, Fari M Bouanani, Tahar Achour
    Abstract:

    Abstract In this study, the mechanical properties of the aged adhesive Adekit A140 epoxy were used in a finite element model to evaluate the effect of water absorption on the adhesive damage in bonded Composite Repair of aircraft structures. The damage zone theory was implemented in the finite element code in order to achieve this objective. In addition, the effect of the water absorption, by the adhesive, on the Repair efficiency was analyzed by computing the stress intensity factor at the crack tip. The obtained results show that, when the water absorption increases the adhesive loses its rigidity, which reduces the Repair durability. Besides, it leads to the increase of the stress intensity factor at the crack tip indicating a reduction in the Repair efficiency.

  • analysis of the adhesive damage for different patch shapes in bonded Composite Repair of aircraft structures
    Materials & Design, 2014
    Co-Authors: F Benyahia, A Albedah, Bel Abbes Bachir Bouiadjra
    Abstract:

    Abstract In this study, the adhesive damage in bonded Composite Repair of aircraft structures is analyzed using a three dimensional finite element method. Four different patch shapes were chosen to analyze the adhesive damage: rectangular, trapezoidal, circular and elliptical. The modified damage zone theory was implemented in the FE code to evaluate the adhesive damage. The obtained results show that the rectangular shape is beneficial for the Repair durability but it presents a disadvantage for the Repair efficiency. The elliptical patch is found the optimal whereas the trapezoidal patch represents the worst shape among the four types analyzed in this paper.

M Belhouari - One of the best experts on this subject based on the ideXlab platform.

  • analysis of the adhesive failure in bonded Composite Repair of aircraft structures using modified damage zone theory
    Materials & Design, 2013
    Co-Authors: Fari M Bouanani, Bel Abbes Bachir Bouiadjra, F Benyahia, A Albedah, M Belhouari
    Abstract:

    Abstract Adhesives play important roles in bonded Composite Repair as it ensures the transfer of load between the Composite patch and the cracked aluminum component. Also, it holds the two structures together. The damage of the adhesive can thus reduce significantly the efficiency and the durability of the bonded Composite Repair. The adhesive damage models using critical zone have proven their effectiveness due to simplicity and applicability of the damage criteria in these models. The scope of this study is the estimation of the adhesive damage and failure in bonded Composite Repair of aircraft structures using modified damage zone theory. The effect of this damage on the Repair efficiency was analyzed. In order to achieve these objectives, non-linear finite element analyses of adhesive joints considering the material nonlinearity of the adhesive layer were performed. The obtained results show that adhesive damage is principally located at the free edges of the patch and over the crack region. The damage zone ratios depends on the applied load, it affects the Repair efficiency when its value approaches the critical value of 0.22.

  • optimisation of the sizes of bonded Composite Repair in aircraft structures
    Materials & Design, 2012
    Co-Authors: S.m. Fekih, Bel Abbes Bachir Bouiadjra, F Benyahia, A Albedah, M Belhouari, A Miloudi
    Abstract:

    Abstract In this study the three-dimensional nonlinear finite element method is used to determine the J integral variation along the front of Repaired crack with bonded Composite patch in aircraft structures. It is known that several parameters influence the Repair quality such as the size and the intrinsic properties of the adhesive, the patch and the plate. The experimental design method is used to investigate the effects of patch dimensions (length, width and thickness) in order to achieve an optimisation of the Repair operation. This optimisation allows us to determine the most influencing parameters on the Repair performances. One can thus help the patch designers to improve the Repair quality and durability.

  • numerical analysis of the patch shape effects on the performances of bonded Composite Repair in aircraft structures
    Composites Part B-engineering, 2012
    Co-Authors: Mhamdia Rachid, Bel Abbes Bachir Bouiadjra, Boualem Serier, M Belhouari
    Abstract:

    Abstract In this study, the three-dimensional finite element method is used to analyze the effects of the patch shape on the efficiency end the durability of bonded Composite Repairs of aircraft structures. The stress intensity factor at the crack tip is used as fracture criteria. The determination of this factor allows us to estimate the Repair efficiency. The analysis of the stresses distribution in the adhesive layer allows us to estimate the durability of the adhesion between the damaged plate and the Composite patch. The obtained results show that the Repair performances are closely related to the patch shape. It was demonstrated that the rectangular shape of the patch could be improved using an “H” shape of the patch. This last shape could also be improved using an arrow shape.

  • effect of Composite hygrothermal aging on the sif variation in bonded Composite Repair of aircraft structures
    Journal of Reinforced Plastics and Composites, 2010
    Co-Authors: L Rezgani, Bel Abbes Bachir Bouiadjra, M Belhouari, Boualem Serier, K. Madani, Xavier Feaugas
    Abstract:

    In this study, the finite element method is used to analyze the effect of hygrothermal aging of Composite on the stress intensity factor variation for the crack Repaired with bonded Composite patch. The obtained results show that moisture absorption has a negative effect on the Repair performance. Indeed, the stress intensity factor increases with an increase in the water absorption in both mode I and mixed mode of crack propagation. The fatigue life of the Repaired structures decreases with the increase in water absorption by the Composite patch.

  • Analysis of the plastic zone size ahead of Repaired cracks with bonded Composite patch of metallic aircraft structures
    Computational Materials Science, 2009
    Co-Authors: Wahid Oudad, S. Touzain, Bel Abbes Bachir Bouiadjra, M Belhouari, Xavier Feaugas
    Abstract:

    In this study, the three-dimensional and non-linear finite element method is used to estimate the performance of the bonded Composite Repair of metallic aircraft structures by analyzing the plastic zone size ahead of Repaired cracks. Several calculations have been realized to extract the plasticized elements around the crack tip of Repaired crack. The obtained results show that the presence of the Composite patch reduces considerably the size of the plastic zone ahead of the crack. The effects of the adhesive properties and the patch thickness on the plastic zone size ahead of Repaired cracks were analyzed.

F Benyahia - One of the best experts on this subject based on the ideXlab platform.

  • effect of the patch length on the effectiveness of one sided bonded Composite Repair for aluminum panels
    International Journal of Adhesion and Adhesives, 2018
    Co-Authors: A Albedah, Bel Abbes Bachir Bouiadjra, Sohail Khan M A Mohammed, F Benyahia
    Abstract:

    Abstract This study analyzes the effect of the patch length the Repair performance of bonded Composite Repair. Experimental and numerical approaches are used. In the experimental part of the study, fatigue tests with a constant amplitude were performed on notched specimens of 2024 T3 and 7075 T6 aeronautical aluminum alloys. Two stress ratios of R = 0 and R=0.1 were applied. The value of the patch length was varied to highlight its effect on the fatigue life. In the numerical part, the stress intensity factor and adhesive stresses were computed for different sizes of the patch length. The experimental results show that the fatigue life of Repaired plates is significantly reduced with increases in patch length irrespective of the type of aluminum alloy and the stress ratio. The numerical results show that the stress intensity factor increases with increases in the patch length, and this is in agreement with the experimental results. This effect is explained by the presence of a secondary bending moment generated by the application of a single sided Composite patch.

  • experimental and numerical analysis of bonded Composite patch Repair in aluminum alloy 7075 t6
    Materials & Design, 2015
    Co-Authors: F Benyahia, Bel Abbes Bachir Bouiadjra, A Albedah, L Aminallah, Tahar Achour
    Abstract:

    Abstract In this study, the performances of aged bonded Composite Repair of aircraft structures have been evaluated by conducting experimental and numerical investigations. The accelerating aging of the patch was realized by immersion in water for 120 days. The performance of aged and non-aged bonded Composite patches in the Repair of cracked structures was evaluated. The experimental results showed that the fatigue life of the aircraft structures can be significantly improved with the patch Repair. The patch aging reduces the Repair performances because of the reduction of the Composite rigidity by humidity absorption. Numerical results show that the stress intensity factor at the crack tip is significantly reduced by the presence of the patch. The humidity absorption increases the stress intensity factor at the crack tip and decreases the adhesive stresses. Nevertheless, the Repair durability cannot be improved by the humidity absorption because it leads to a reduction of the mechanical resistance of the adhesive.

  • elliptical and circular bonded Composite Repair under mechanical and thermal loading in aircraft structures
    Materials Research-ibero-american Journal of Materials, 2014
    Co-Authors: F Benyahia, A Albedah, Bel Abbes Bachir Bouiadjra
    Abstract:

    In this study, the three-dimensional finite element method is used to achieve a comparison between the semi circular and semi elliptical patch Repairs in aircraft structures. The comparison was done by the analysis of : the mechanical and thermal stress intensity factors (SIF and TSIF) at the tip of Repaired crack and the distribution of the adhesive stresses for the two patch shapes. The obtained results show that the semi circular shape of the patch presents lower stress intensity factor at the crack tip, which is beneficial for the fatigue life and lower adhesives stresses, which is beneficial for the Repair durability. In addition the circular patch is subjected to less significant thermal residual stresses compared to the elliptical shapes.

  • effect of water absorption on the adhesive damage in bonded Composite Repair of aircraft structures
    Materials & Design, 2014
    Co-Authors: F Benyahia, Bel Abbes Bachir Bouiadjra, A Albedah, Fari M Bouanani, Tahar Achour
    Abstract:

    Abstract In this study, the mechanical properties of the aged adhesive Adekit A140 epoxy were used in a finite element model to evaluate the effect of water absorption on the adhesive damage in bonded Composite Repair of aircraft structures. The damage zone theory was implemented in the finite element code in order to achieve this objective. In addition, the effect of the water absorption, by the adhesive, on the Repair efficiency was analyzed by computing the stress intensity factor at the crack tip. The obtained results show that, when the water absorption increases the adhesive loses its rigidity, which reduces the Repair durability. Besides, it leads to the increase of the stress intensity factor at the crack tip indicating a reduction in the Repair efficiency.

  • analysis of the adhesive damage for different patch shapes in bonded Composite Repair of aircraft structures
    Materials & Design, 2014
    Co-Authors: F Benyahia, A Albedah, Bel Abbes Bachir Bouiadjra
    Abstract:

    Abstract In this study, the adhesive damage in bonded Composite Repair of aircraft structures is analyzed using a three dimensional finite element method. Four different patch shapes were chosen to analyze the adhesive damage: rectangular, trapezoidal, circular and elliptical. The modified damage zone theory was implemented in the FE code to evaluate the adhesive damage. The obtained results show that the rectangular shape is beneficial for the Repair durability but it presents a disadvantage for the Repair efficiency. The elliptical patch is found the optimal whereas the trapezoidal patch represents the worst shape among the four types analyzed in this paper.

Boualem Serier - One of the best experts on this subject based on the ideXlab platform.

  • numerical analysis of the patch shape effects on the performances of bonded Composite Repair in aircraft structures
    Composites Part B-engineering, 2012
    Co-Authors: Mhamdia Rachid, Bel Abbes Bachir Bouiadjra, Boualem Serier, M Belhouari
    Abstract:

    Abstract In this study, the three-dimensional finite element method is used to analyze the effects of the patch shape on the efficiency end the durability of bonded Composite Repairs of aircraft structures. The stress intensity factor at the crack tip is used as fracture criteria. The determination of this factor allows us to estimate the Repair efficiency. The analysis of the stresses distribution in the adhesive layer allows us to estimate the durability of the adhesion between the damaged plate and the Composite patch. The obtained results show that the Repair performances are closely related to the patch shape. It was demonstrated that the rectangular shape of the patch could be improved using an “H” shape of the patch. This last shape could also be improved using an arrow shape.

  • stress intensity factor for Repaired crack with bonded Composite patch under thermo mechanical loading
    Journal of Reinforced Plastics and Composites, 2011
    Co-Authors: R Mhamdia, Xavier Feaugas, Boualem Serier, Bachir B Bouadjra, W Ouddad, S. Touzain
    Abstract:

    In this study, the finite element method is used to analyze the effect of the thermal residual stresses resulting from adhesive curing on the performances of the bonded Composite Repair in aircraft structures. The stress intensity factor at the crack tip is chosen as the fracture criterion in order to estimate the Repair performances. The effects of the curing temperature, the geometrical properties of the patch, and the adhesive properties on the variation of the stress intensity factor are analyzed. The obtained results show a significant negative effect of the thermal residual stresses on the Repair efficiency and this effect can be reduced if the different Repair parameters are optimized.

  • effect of Composite hygrothermal aging on the sif variation in bonded Composite Repair of aircraft structures
    Journal of Reinforced Plastics and Composites, 2010
    Co-Authors: L Rezgani, Bel Abbes Bachir Bouiadjra, M Belhouari, Boualem Serier, K. Madani, Xavier Feaugas
    Abstract:

    In this study, the finite element method is used to analyze the effect of hygrothermal aging of Composite on the stress intensity factor variation for the crack Repaired with bonded Composite patch. The obtained results show that moisture absorption has a negative effect on the Repair performance. Indeed, the stress intensity factor increases with an increase in the water absorption in both mode I and mixed mode of crack propagation. The fatigue life of the Repaired structures decreases with the increase in water absorption by the Composite patch.

  • Energy Release Rate for Repaired Inclined Cracks with Bonded Composite Patch Having Two Adhesive Bands in Aircraft Structures
    Journal of Reinforced Plastics and Composites, 2008
    Co-Authors: Bel Abbes Bachir Bouiadjra, Hamida Fekirini, M Belhouari, Boualem Serier, Mohamed Benguediab
    Abstract:

    Adhesive in bonded Composite Repair plays two opposite roles. The first consists in ensuring the transfer of load between the Composite patch and the cracked aluminum component. The second role is to ensure the connection between these two structures in order to avoid the adhesive failure. In this study, a method of Repair is proposed; it consists in dividing the adhesive layer into two bands with different properties. The first band is bonded on the crack region to ensure the stress transfer and the second band is bonded beyond the crack region to avoid the adhesive failure. The case of mixed mode loading (inclined crack) is studied. The energy release rate at the crack tip is computed for this Repair configuration using the finite element method. The obtained results show that the energy release rate at the crack tip is considerably reduced by the difference of properties between the two adhesive bands, which can imply the improvement of fatigue life of cracked structures.

  • numerical analysis of the performances of bonded Composite Repair with two adhesive bands in aircraft structures
    Composite Structures, 2008
    Co-Authors: Hamida Fekirini, M Belhouari, Benali Boutabout, Boualem Serier
    Abstract:

    Adhesive in bonded Composite Repair plays two opposite roles. The first consists in ensuring the transfer of load between the Composite patch and the cracked aluminium component. The second role is to ensure the connection between these two structures in order to avoid the adhesive failure. In this study, a method of Repair is proposed; it consists in dividing the adhesive layer into two bands with different properties. The first band is used on the crack region to ensure the stress transfer and the second band is used beyond the crack region to avoid the adhesive failure. The stress intensity factor at the crack tip is computed for this Repair configuration using the finite element method. The obtained results show that the SIF at the crack tip is highly reduced by the difference of properties between the two adhesive bands, what can involve the improvement of fatigue life of cracked structures.

A Albedah - One of the best experts on this subject based on the ideXlab platform.

  • effect of the patch length on the effectiveness of one sided bonded Composite Repair for aluminum panels
    International Journal of Adhesion and Adhesives, 2018
    Co-Authors: A Albedah, Bel Abbes Bachir Bouiadjra, Sohail Khan M A Mohammed, F Benyahia
    Abstract:

    Abstract This study analyzes the effect of the patch length the Repair performance of bonded Composite Repair. Experimental and numerical approaches are used. In the experimental part of the study, fatigue tests with a constant amplitude were performed on notched specimens of 2024 T3 and 7075 T6 aeronautical aluminum alloys. Two stress ratios of R = 0 and R=0.1 were applied. The value of the patch length was varied to highlight its effect on the fatigue life. In the numerical part, the stress intensity factor and adhesive stresses were computed for different sizes of the patch length. The experimental results show that the fatigue life of Repaired plates is significantly reduced with increases in patch length irrespective of the type of aluminum alloy and the stress ratio. The numerical results show that the stress intensity factor increases with increases in the patch length, and this is in agreement with the experimental results. This effect is explained by the presence of a secondary bending moment generated by the application of a single sided Composite patch.

  • experimental and numerical analysis of bonded Composite patch Repair in aluminum alloy 7075 t6
    Materials & Design, 2015
    Co-Authors: F Benyahia, Bel Abbes Bachir Bouiadjra, A Albedah, L Aminallah, Tahar Achour
    Abstract:

    Abstract In this study, the performances of aged bonded Composite Repair of aircraft structures have been evaluated by conducting experimental and numerical investigations. The accelerating aging of the patch was realized by immersion in water for 120 days. The performance of aged and non-aged bonded Composite patches in the Repair of cracked structures was evaluated. The experimental results showed that the fatigue life of the aircraft structures can be significantly improved with the patch Repair. The patch aging reduces the Repair performances because of the reduction of the Composite rigidity by humidity absorption. Numerical results show that the stress intensity factor at the crack tip is significantly reduced by the presence of the patch. The humidity absorption increases the stress intensity factor at the crack tip and decreases the adhesive stresses. Nevertheless, the Repair durability cannot be improved by the humidity absorption because it leads to a reduction of the mechanical resistance of the adhesive.

  • elliptical and circular bonded Composite Repair under mechanical and thermal loading in aircraft structures
    Materials Research-ibero-american Journal of Materials, 2014
    Co-Authors: F Benyahia, A Albedah, Bel Abbes Bachir Bouiadjra
    Abstract:

    In this study, the three-dimensional finite element method is used to achieve a comparison between the semi circular and semi elliptical patch Repairs in aircraft structures. The comparison was done by the analysis of : the mechanical and thermal stress intensity factors (SIF and TSIF) at the tip of Repaired crack and the distribution of the adhesive stresses for the two patch shapes. The obtained results show that the semi circular shape of the patch presents lower stress intensity factor at the crack tip, which is beneficial for the fatigue life and lower adhesives stresses, which is beneficial for the Repair durability. In addition the circular patch is subjected to less significant thermal residual stresses compared to the elliptical shapes.

  • effect of water absorption on the adhesive damage in bonded Composite Repair of aircraft structures
    Materials & Design, 2014
    Co-Authors: F Benyahia, Bel Abbes Bachir Bouiadjra, A Albedah, Fari M Bouanani, Tahar Achour
    Abstract:

    Abstract In this study, the mechanical properties of the aged adhesive Adekit A140 epoxy were used in a finite element model to evaluate the effect of water absorption on the adhesive damage in bonded Composite Repair of aircraft structures. The damage zone theory was implemented in the finite element code in order to achieve this objective. In addition, the effect of the water absorption, by the adhesive, on the Repair efficiency was analyzed by computing the stress intensity factor at the crack tip. The obtained results show that, when the water absorption increases the adhesive loses its rigidity, which reduces the Repair durability. Besides, it leads to the increase of the stress intensity factor at the crack tip indicating a reduction in the Repair efficiency.

  • analysis of the adhesive damage for different patch shapes in bonded Composite Repair of aircraft structures
    Materials & Design, 2014
    Co-Authors: F Benyahia, A Albedah, Bel Abbes Bachir Bouiadjra
    Abstract:

    Abstract In this study, the adhesive damage in bonded Composite Repair of aircraft structures is analyzed using a three dimensional finite element method. Four different patch shapes were chosen to analyze the adhesive damage: rectangular, trapezoidal, circular and elliptical. The modified damage zone theory was implemented in the FE code to evaluate the adhesive damage. The obtained results show that the rectangular shape is beneficial for the Repair durability but it presents a disadvantage for the Repair efficiency. The elliptical patch is found the optimal whereas the trapezoidal patch represents the worst shape among the four types analyzed in this paper.