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Toshiyuki Sawa - One of the best experts on this subject based on the ideXlab platform.
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numerical analysis on load bearing capacity and damage of double Scarf adhesive joints subjected to combined loadings of tension and bending
International Journal of Adhesion and Adhesives, 2014Co-Authors: Lijuan Liao, Toshiyuki Sawa, Chenguang HuangAbstract:The load-bearing capacity and the damage level of the double Scarf joint (DSJ) under combined loadings of tension and bending were investigated numerically, which takes into account the effects of Scarf Angle and adhesive type. A finite element method (FEM), which includes a mixed-mode cohesive zone model (CZM) with a bilinear shape, was employed to govern the interface separation behaviors. At the point corresponding to the ultimate loading, it was observed that the interface damage level of DSJ with the ductile adhesive is higher and more uniform than that of the joint with the brittle one. More than that, the numerical results illustrated that the failure of DSJ is controlled not only by the ultimate loading, but also by the applied displacement until complete failure. Therefore, the failure energy, which is defined as the integral of the loading with respect to the displacement, was adopted to estimate the joint performance. Subsequently, the numerical results showed that the failure energy of the joint with the ductile adhesive is higher than that of the joint with the brittle one. Furthermore, all the discussed characteristic parameters of a DSJ with a given adhesive, including ultimate loading, the von-Mises equivalent stress and interface damage level corresponding to the ultimate loading, and the failure energy, were inversely proportional to the Scarf Angle. Finally, through comparing with the existing experimental measurements, the adoptive method was validated. (C) 2014 Elsevier Ltd. All rights reserved.
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effect of adhesive thickness adhesive type and Scarf Angle on the mechanical properties of Scarf adhesive joints
International Journal of Solids and Structures, 2013Co-Authors: Lijuan Liao, Chenguang Huang, Toshiyuki SawaAbstract:The effects of adhesive thickness, adhesive type and Scarf Angle, which are determined as the main control parameters by the dimensional analysis, on the mechanical properties of a Scarf adhesive joint (SJ) subjected to uniaxial tensile loading are examined using a mixed-mode cohesive zone model (CZM) with a bilinear shape to govern the interface separation. Particularly, the adhesive-dependence of the vital cohesive parameters of CZM, which mainly include initial stiffness, total fracture energy and separation strength, is introduced emphatically. The numerical results demonstrate that the ultimate tensile loading increases as the adhesive thickness decreases. Cross the ultimate tension, the joint loses the load-bearing capacity when adopting the brittle adhesive but sustains partial load-bearing capacity while selecting the ductile adhesive. In addition, for the joint with the ductile adhesive, the maximum applied displacement until the complete failure of it is directly proportional to the adhesive thickness, which is different from the case using the brittle adhesive. Taking the combination of the ultimate loading and applied displacement into account, failure energy is employed to evaluate the joint performances. The results show that the failure energy of the joint with the brittle adhesive increases as the adhesive thickness decreases. Conversely, the situation of the joint using the ductile adhesive is vice versa. Moreover, the effect of the adhesive thickness becomes more noticeable with decreasing the Scarf Angle owing to the variation of the proportion of each component of the mixed-mode. Furthermore, all the characteristic parameters (the ultimate tensile loading, the maximum applied displacement and the failure energy) that adopted to describe the performances of SJ increase as the Scarf Angle decreases. Finally, the numerical method employed in this study is validated by comparing with existing experimental results. ? 2013 Elsevier Ltd. All rights reserved.
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Analysis on Failure Mechanism of Scarf Joints With Brittle-Ductile Adhesives Subjected to Uniaxial Tensile Loads
Volume 2B: Advanced Manufacturing, 2013Co-Authors: Lijuan Liao, Toshiyuki Sawa, Chenguang HuangAbstract:The failure mechanism of Scarf joints with a series of Angles and brittle-ductile adhesives subjected to uniaxial tensile loads is analyzed by using a numerical method which employs a cohesive zone model (CZM) with a bilinear shape in mixed-mode (mode I and II). The adopted methodology is validated via comparisons between the present simulated results and the existing experimental measurements, which illustrate that the load-bearing capacity increases as the Scarf Angle decreases. More important, it is observed that the failure of the joint is governed by not only the ultimate tensile loads, but also the applied tensile displacement until complete failure, which is related to the brittle-ductile properties of the adhesive layer. In addition, failure energy, which is defined by using the area of the load-displacement curve of the joint, is adopted to estimate the joint strength. Subsequently, the numerical results show that the strength of the joint adopting ductile adhesive with higher failure energy is higher than that of the joint using brittle adhesive with lower failure energy.
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fem stress analysis and strength prediction of Scarf adhesive joints under static bending moments
International Journal of Adhesion and Adhesives, 2013Co-Authors: Hiroko Nakano, Yasuhisa Sekiguchi, Toshiyuki SawaAbstract:Abstract The stress distributions at the interfaces in the Scarf adhesive joints under static bending moments were analyzed using two-dimensional and three-dimensional finite element (FEM) calculations. The effects of the Scarf Angle, adhesive Young's modulus and the adhesive thickness on the interface stress distribution were examined. It was found that the singular stress at the edges of the interfaces decreased as the adhesive Young's modulus increased and the adhesive thickness decreased. The singular stress at the edges of the interfaces obtained from the 3-D was larger than that from the 2-D FEM. The joint strength was also predicted using the elasto-plastic 3-D FEM calculations. For verification of the FEM calculation results, the strains in the adherends and the joint strengths were measured. The measured results of the strains and the joint strengths were fairly consistent with the results obtained from the 3-D FEM calculations and indicated that the rupture bending moment (joint strength) was the maximum when the Scarf Angle was around 60°.
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fem stress analysis and strength prediction of stepped lap adhesive joints of similar hollow cylinders under static tensile loadings
ASME 2011 International Mechanical Engineering Congress and Exposition, 2011Co-Authors: Kazunari Kotajima, Yasuhisa Sekiguchi, Takashi Kobayashi, Yuta Ueda, Toshiyuki SawaAbstract:This paper deals with an FEM stress analysis of stepped-lap adhesive joints of similar hollow cylinders under static tensile loadings. The effects of Young’s modulus ratio between the adherends and adhesive, the thickness of the adhesive, Scarf Angle, the number of steps, and singular stress on the interface stress distributions are calculated using FEM. The code of FEM employed is ANSYS. The singular stress is found to occur at the edge of the interfaces. The singular stress at the inside edge is larger than that at the outside edge. It is shown that the maximum principal stress at the edge of the interface decreases as Young’s modulus ratio between the adherend and the adhesive and the adhesive thickness decreases while it decreases as the number of steps increases. Using the obtained interface stress distribution, we can predict the joint strength. For verification of the strength prediction, experiments to measure the joint strength were carried out. The numerical results of the joint strength are in a fairly good agreement with the experimental results.Copyright © 2011 by ASME
Hamit Adin - One of the best experts on this subject based on the ideXlab platform.
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effect of overlap length and Scarf Angle on the mechanical properties of different adhesive joints subjected to tensile loads
Materials Testing-Materials and Components Technology and Application, 2017Co-Authors: Hamit AdinAbstract:Abstract In this study, the effect of adherend dimensions and Scarf Angle on mechanical behavior of different adhesively bonded joints was analyzed. The adhesive joints were subjected to tensile lo...
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the investigation of the effect of Angle on the failure load and strength of Scarf lap joints
International Journal of Mechanical Sciences, 2012Co-Authors: Hamit AdinAbstract:Abstract In this study, the effect of Scarf Angle on tensile strength of an epoxy adhesive was investigated both experimentally and numerically. Tensile tests were carried out using Scarf Lap Joints (SLJs). Commercially available epoxy (Atlac 580) was used as adhesive and fiber reinforced epoxy/glass (Hgw 2372 Grade G10 EP GC 203) was used as adherends. The stress analyses were performed using a three-dimensional Finite Element Method (FEM). The FEM analyses were executed with Ansys (V.14.0.1). Experimental results were compared with the FEM results and found quite reasonable. The results have indicated that when overlap Angle increases, the failure load values also decrease in all joints.
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the effect of Angle on the strain of Scarf lap joints subjected to tensile loads
Applied Mathematical Modelling, 2012Co-Authors: Hamit AdinAbstract:Abstract In this paper, the mechanical behavior of the Scarf lap joints (SLJs) bonded with adhesive (Vinylester Atlac 580) under a tensile load was analyzed. The effects of Scarf Angle at the interface strain distributions of SLJs were examined. The stress analyses were performed via three dimensional Finite Element Method (3D-FEM). The 3D-FEM code employed was Ansys (12.0). Experimental results were compared with the 3D-FEM results and were found quite reasonable. The results indicated that the maximum values of the normalized e x strain values were determined at θ = 60° in all joints.
Chenguang Huang - One of the best experts on this subject based on the ideXlab platform.
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numerical analysis of effects of adhesive type and geometry on mixed mode failure of adhesive joint
International Journal of Adhesion and Adhesives, 2016Co-Authors: Lijuan Liao, Chenguang HuangAbstract:In the present study, the effects of the adhesive type and geometry (adhesive thickness and Scarf Angle) on mixed-mode failure of double Scarf adhesive joint (DSJ) under uniaxial tensile loading were numerically examined using the finite element subroutine which coupled with a mixed-mode cohesive zone model (CZM). Especially, the effects of the adhesive type, which actually represent the influences of the cohesive parameters in mode I and mode II, on the mechanical properties of DSJ were discussed systematically. The numerical results reveal that the ultimate tensile loading and the necessary energy for failure of DSJ are controlled by the intrinsic components in mode I and mode II with different rates. Accordingly, the mathematical expressions for the ultimate tensile loading and the failure energy of DSJ with respect to the thickness-dependency cohesive parameters in two modes (I and II) and the Scarf Angle were deduced to identify each contribution in each mode component for a given type of adhesive. In addition, the numerical results also demonstrate that relationship between the interface damage level (corresponding to the ultimate tensile loading) and the adhesive thickness is not monotonous. However, as an increase of the adhesive thickness, the uniformity of damage level distribution is enhanced. Furthermore, the variation of the interface damage level with respect to the Scarf Angle is also not monotonous for each adhesive thickness. It can be concluded that the effects of the Scarf Angle and the adhesive thickness on the mixed-mode failure of DSJ are coupled rather than independently. (C) 2015 Elsevier Ltd. All rights reserved.
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numerical analysis of effect of cohesive parameters on mixed mode failure of double Scarf adhesive joint subjected to uniaxial tensile loadings
ASME 2015 International Mechanical Engineering Congress and Exposition, 2015Co-Authors: Lijuan Liao, Chenguang HuangAbstract:In the present study, the effects of cohesive parameters on the mixed-mode failure of double-Scarf adhesive joint (DSAJ) subjected to uniaxial tensile loadings were examined and discussed numerically. For DSAJ with no perpendicular or parallel with the external loading direction, complex stress state (mixture of tensile and shear stresses) occurs at the adhesive interface. In addition, adhesive joint failure, which is a gradually process rather than a sudden transition, is accompanied by energy dissipates gradually at the crack tip. Correspondingly, cohesive zone model (CZM) coupled with finite element method (FEM) was implemented to verify the mechanism of crack from initiation to the complete failure. As the constitutive relation of the adhesive layer, the traction-separation (T-S) law determines the interface damage evolution. Additionally, the shape of T-S curves in mode I and mode II are crucially decided by the cohesive strengths and critical fracture energies in each mode, respectively. Firstly, the non-dimensional-normalized form of ultimate tensile loading of DSAJ was obtained using dimensional analysis. Then, three cases of cohesive parameters (case of constant anisotropy extent & case of constant critical fracture energy in each mode & case of constant cohesive strength in each mode) according to the non-dimensional-normalized form of adhesive properties were designed. Two types adhesives (brittle and ductile) were chosen to examine the effects of adhesive properties on the failure of DSAJ in this study. To avoid the influence of the geometries on DSAJ mechanical behaviors, the thickness of the adhesive layer and the Scarf Angle θ were held constantly, respectively. In numerical calculations, the change trends of the ultimate tensile loading (Fu), the failure energy (Ef) and the damage level (D) corresponding to Fu with respect to the cohesive parameters were discussed. It can be observed the cohesive strengths in mode I and mode II codetermine Fu of DSAJ with unequal rates. Moreover, Ef of DSAJ, which is the necessary energy for the joint failure, is governed by the critical fracture energies in mode I and mode II with different contributions. Besides, it also obtained that the evolutions of D corresponding to Fu of DSAJ with brittle and ductile adhesives are certain different. Generally, D of DSAJ with brittle adhesive is higher and more uneven than that of DSAJ with ductile adhesive. Accordingly, it can be concluded that DSAJ with brittle adhesive has lower ability to distribute the loading over a smaller cohesive zone with less uniform distribution. In addition, the numerical results revealed that with the increment of ratio in each case set in this paper, D of DSAJ does not rise obviously.Copyright © 2015 by ASME
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numerical analysis on load bearing capacity and damage of double Scarf adhesive joints subjected to combined loadings of tension and bending
International Journal of Adhesion and Adhesives, 2014Co-Authors: Lijuan Liao, Toshiyuki Sawa, Chenguang HuangAbstract:The load-bearing capacity and the damage level of the double Scarf joint (DSJ) under combined loadings of tension and bending were investigated numerically, which takes into account the effects of Scarf Angle and adhesive type. A finite element method (FEM), which includes a mixed-mode cohesive zone model (CZM) with a bilinear shape, was employed to govern the interface separation behaviors. At the point corresponding to the ultimate loading, it was observed that the interface damage level of DSJ with the ductile adhesive is higher and more uniform than that of the joint with the brittle one. More than that, the numerical results illustrated that the failure of DSJ is controlled not only by the ultimate loading, but also by the applied displacement until complete failure. Therefore, the failure energy, which is defined as the integral of the loading with respect to the displacement, was adopted to estimate the joint performance. Subsequently, the numerical results showed that the failure energy of the joint with the ductile adhesive is higher than that of the joint with the brittle one. Furthermore, all the discussed characteristic parameters of a DSJ with a given adhesive, including ultimate loading, the von-Mises equivalent stress and interface damage level corresponding to the ultimate loading, and the failure energy, were inversely proportional to the Scarf Angle. Finally, through comparing with the existing experimental measurements, the adoptive method was validated. (C) 2014 Elsevier Ltd. All rights reserved.
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effect of adhesive thickness adhesive type and Scarf Angle on the mechanical properties of Scarf adhesive joints
International Journal of Solids and Structures, 2013Co-Authors: Lijuan Liao, Chenguang Huang, Toshiyuki SawaAbstract:The effects of adhesive thickness, adhesive type and Scarf Angle, which are determined as the main control parameters by the dimensional analysis, on the mechanical properties of a Scarf adhesive joint (SJ) subjected to uniaxial tensile loading are examined using a mixed-mode cohesive zone model (CZM) with a bilinear shape to govern the interface separation. Particularly, the adhesive-dependence of the vital cohesive parameters of CZM, which mainly include initial stiffness, total fracture energy and separation strength, is introduced emphatically. The numerical results demonstrate that the ultimate tensile loading increases as the adhesive thickness decreases. Cross the ultimate tension, the joint loses the load-bearing capacity when adopting the brittle adhesive but sustains partial load-bearing capacity while selecting the ductile adhesive. In addition, for the joint with the ductile adhesive, the maximum applied displacement until the complete failure of it is directly proportional to the adhesive thickness, which is different from the case using the brittle adhesive. Taking the combination of the ultimate loading and applied displacement into account, failure energy is employed to evaluate the joint performances. The results show that the failure energy of the joint with the brittle adhesive increases as the adhesive thickness decreases. Conversely, the situation of the joint using the ductile adhesive is vice versa. Moreover, the effect of the adhesive thickness becomes more noticeable with decreasing the Scarf Angle owing to the variation of the proportion of each component of the mixed-mode. Furthermore, all the characteristic parameters (the ultimate tensile loading, the maximum applied displacement and the failure energy) that adopted to describe the performances of SJ increase as the Scarf Angle decreases. Finally, the numerical method employed in this study is validated by comparing with existing experimental results. ? 2013 Elsevier Ltd. All rights reserved.
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Analysis on Failure Mechanism of Scarf Joints With Brittle-Ductile Adhesives Subjected to Uniaxial Tensile Loads
Volume 2B: Advanced Manufacturing, 2013Co-Authors: Lijuan Liao, Toshiyuki Sawa, Chenguang HuangAbstract:The failure mechanism of Scarf joints with a series of Angles and brittle-ductile adhesives subjected to uniaxial tensile loads is analyzed by using a numerical method which employs a cohesive zone model (CZM) with a bilinear shape in mixed-mode (mode I and II). The adopted methodology is validated via comparisons between the present simulated results and the existing experimental measurements, which illustrate that the load-bearing capacity increases as the Scarf Angle decreases. More important, it is observed that the failure of the joint is governed by not only the ultimate tensile loads, but also the applied tensile displacement until complete failure, which is related to the brittle-ductile properties of the adhesive layer. In addition, failure energy, which is defined by using the area of the load-displacement curve of the joint, is adopted to estimate the joint strength. Subsequently, the numerical results show that the strength of the joint adopting ductile adhesive with higher failure energy is higher than that of the joint using brittle adhesive with lower failure energy.
Lijuan Liao - One of the best experts on this subject based on the ideXlab platform.
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numerical analysis of effects of adhesive type and geometry on mixed mode failure of adhesive joint
International Journal of Adhesion and Adhesives, 2016Co-Authors: Lijuan Liao, Chenguang HuangAbstract:In the present study, the effects of the adhesive type and geometry (adhesive thickness and Scarf Angle) on mixed-mode failure of double Scarf adhesive joint (DSJ) under uniaxial tensile loading were numerically examined using the finite element subroutine which coupled with a mixed-mode cohesive zone model (CZM). Especially, the effects of the adhesive type, which actually represent the influences of the cohesive parameters in mode I and mode II, on the mechanical properties of DSJ were discussed systematically. The numerical results reveal that the ultimate tensile loading and the necessary energy for failure of DSJ are controlled by the intrinsic components in mode I and mode II with different rates. Accordingly, the mathematical expressions for the ultimate tensile loading and the failure energy of DSJ with respect to the thickness-dependency cohesive parameters in two modes (I and II) and the Scarf Angle were deduced to identify each contribution in each mode component for a given type of adhesive. In addition, the numerical results also demonstrate that relationship between the interface damage level (corresponding to the ultimate tensile loading) and the adhesive thickness is not monotonous. However, as an increase of the adhesive thickness, the uniformity of damage level distribution is enhanced. Furthermore, the variation of the interface damage level with respect to the Scarf Angle is also not monotonous for each adhesive thickness. It can be concluded that the effects of the Scarf Angle and the adhesive thickness on the mixed-mode failure of DSJ are coupled rather than independently. (C) 2015 Elsevier Ltd. All rights reserved.
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numerical analysis of effect of cohesive parameters on mixed mode failure of double Scarf adhesive joint subjected to uniaxial tensile loadings
ASME 2015 International Mechanical Engineering Congress and Exposition, 2015Co-Authors: Lijuan Liao, Chenguang HuangAbstract:In the present study, the effects of cohesive parameters on the mixed-mode failure of double-Scarf adhesive joint (DSAJ) subjected to uniaxial tensile loadings were examined and discussed numerically. For DSAJ with no perpendicular or parallel with the external loading direction, complex stress state (mixture of tensile and shear stresses) occurs at the adhesive interface. In addition, adhesive joint failure, which is a gradually process rather than a sudden transition, is accompanied by energy dissipates gradually at the crack tip. Correspondingly, cohesive zone model (CZM) coupled with finite element method (FEM) was implemented to verify the mechanism of crack from initiation to the complete failure. As the constitutive relation of the adhesive layer, the traction-separation (T-S) law determines the interface damage evolution. Additionally, the shape of T-S curves in mode I and mode II are crucially decided by the cohesive strengths and critical fracture energies in each mode, respectively. Firstly, the non-dimensional-normalized form of ultimate tensile loading of DSAJ was obtained using dimensional analysis. Then, three cases of cohesive parameters (case of constant anisotropy extent & case of constant critical fracture energy in each mode & case of constant cohesive strength in each mode) according to the non-dimensional-normalized form of adhesive properties were designed. Two types adhesives (brittle and ductile) were chosen to examine the effects of adhesive properties on the failure of DSAJ in this study. To avoid the influence of the geometries on DSAJ mechanical behaviors, the thickness of the adhesive layer and the Scarf Angle θ were held constantly, respectively. In numerical calculations, the change trends of the ultimate tensile loading (Fu), the failure energy (Ef) and the damage level (D) corresponding to Fu with respect to the cohesive parameters were discussed. It can be observed the cohesive strengths in mode I and mode II codetermine Fu of DSAJ with unequal rates. Moreover, Ef of DSAJ, which is the necessary energy for the joint failure, is governed by the critical fracture energies in mode I and mode II with different contributions. Besides, it also obtained that the evolutions of D corresponding to Fu of DSAJ with brittle and ductile adhesives are certain different. Generally, D of DSAJ with brittle adhesive is higher and more uneven than that of DSAJ with ductile adhesive. Accordingly, it can be concluded that DSAJ with brittle adhesive has lower ability to distribute the loading over a smaller cohesive zone with less uniform distribution. In addition, the numerical results revealed that with the increment of ratio in each case set in this paper, D of DSAJ does not rise obviously.Copyright © 2015 by ASME
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numerical analysis on load bearing capacity and damage of double Scarf adhesive joints subjected to combined loadings of tension and bending
International Journal of Adhesion and Adhesives, 2014Co-Authors: Lijuan Liao, Toshiyuki Sawa, Chenguang HuangAbstract:The load-bearing capacity and the damage level of the double Scarf joint (DSJ) under combined loadings of tension and bending were investigated numerically, which takes into account the effects of Scarf Angle and adhesive type. A finite element method (FEM), which includes a mixed-mode cohesive zone model (CZM) with a bilinear shape, was employed to govern the interface separation behaviors. At the point corresponding to the ultimate loading, it was observed that the interface damage level of DSJ with the ductile adhesive is higher and more uniform than that of the joint with the brittle one. More than that, the numerical results illustrated that the failure of DSJ is controlled not only by the ultimate loading, but also by the applied displacement until complete failure. Therefore, the failure energy, which is defined as the integral of the loading with respect to the displacement, was adopted to estimate the joint performance. Subsequently, the numerical results showed that the failure energy of the joint with the ductile adhesive is higher than that of the joint with the brittle one. Furthermore, all the discussed characteristic parameters of a DSJ with a given adhesive, including ultimate loading, the von-Mises equivalent stress and interface damage level corresponding to the ultimate loading, and the failure energy, were inversely proportional to the Scarf Angle. Finally, through comparing with the existing experimental measurements, the adoptive method was validated. (C) 2014 Elsevier Ltd. All rights reserved.
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effect of adhesive thickness adhesive type and Scarf Angle on the mechanical properties of Scarf adhesive joints
International Journal of Solids and Structures, 2013Co-Authors: Lijuan Liao, Chenguang Huang, Toshiyuki SawaAbstract:The effects of adhesive thickness, adhesive type and Scarf Angle, which are determined as the main control parameters by the dimensional analysis, on the mechanical properties of a Scarf adhesive joint (SJ) subjected to uniaxial tensile loading are examined using a mixed-mode cohesive zone model (CZM) with a bilinear shape to govern the interface separation. Particularly, the adhesive-dependence of the vital cohesive parameters of CZM, which mainly include initial stiffness, total fracture energy and separation strength, is introduced emphatically. The numerical results demonstrate that the ultimate tensile loading increases as the adhesive thickness decreases. Cross the ultimate tension, the joint loses the load-bearing capacity when adopting the brittle adhesive but sustains partial load-bearing capacity while selecting the ductile adhesive. In addition, for the joint with the ductile adhesive, the maximum applied displacement until the complete failure of it is directly proportional to the adhesive thickness, which is different from the case using the brittle adhesive. Taking the combination of the ultimate loading and applied displacement into account, failure energy is employed to evaluate the joint performances. The results show that the failure energy of the joint with the brittle adhesive increases as the adhesive thickness decreases. Conversely, the situation of the joint using the ductile adhesive is vice versa. Moreover, the effect of the adhesive thickness becomes more noticeable with decreasing the Scarf Angle owing to the variation of the proportion of each component of the mixed-mode. Furthermore, all the characteristic parameters (the ultimate tensile loading, the maximum applied displacement and the failure energy) that adopted to describe the performances of SJ increase as the Scarf Angle decreases. Finally, the numerical method employed in this study is validated by comparing with existing experimental results. ? 2013 Elsevier Ltd. All rights reserved.
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Analysis on Failure Mechanism of Scarf Joints With Brittle-Ductile Adhesives Subjected to Uniaxial Tensile Loads
Volume 2B: Advanced Manufacturing, 2013Co-Authors: Lijuan Liao, Toshiyuki Sawa, Chenguang HuangAbstract:The failure mechanism of Scarf joints with a series of Angles and brittle-ductile adhesives subjected to uniaxial tensile loads is analyzed by using a numerical method which employs a cohesive zone model (CZM) with a bilinear shape in mixed-mode (mode I and II). The adopted methodology is validated via comparisons between the present simulated results and the existing experimental measurements, which illustrate that the load-bearing capacity increases as the Scarf Angle decreases. More important, it is observed that the failure of the joint is governed by not only the ultimate tensile loads, but also the applied tensile displacement until complete failure, which is related to the brittle-ductile properties of the adhesive layer. In addition, failure energy, which is defined by using the area of the load-displacement curve of the joint, is adopted to estimate the joint strength. Subsequently, the numerical results show that the strength of the joint adopting ductile adhesive with higher failure energy is higher than that of the joint using brittle adhesive with lower failure energy.
Yuya Hirayama - One of the best experts on this subject based on the ideXlab platform.
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stress analysis and strength evaluation of Scarf adhesive joints subjected to static tensile loadings
International Journal of Adhesion and Adhesives, 2010Co-Authors: Dan He, Takeshi Iwamoto, Toshiyuki Sawa, Yuya HirayamaAbstract:Abstract The stress distributions in Scarf adhesive joints under static tensile loadings are analyzed using three-dimensional finite-element calculations. The effects of adhesive Young’s modulus, adhesive thickness and Scarf Angle in the adherend on the interface stress distributions are examined. As the results, it is found that the maximum value of the maximum principal stress occurs at the edge of the interfaces. The differences in the interface stress distributions between the 2-D and the 3-D FEM results are demonstrated. It is also observed from the 3-D FEM results that the maximum value of the maximum principal stress is the smallest when the Scarf Angle is around 60 degree, while it is around 52 degree in the 2-D FEM when the singular stress at the edges vanishes. In addition, the joint strength is estimated using the interface stress distribution obtained from the FEM calculations. For verification of the FEM calculations, experiments were carried out to measure the strengths and the strains in the joints under static tensile loadings using strain gauges. Fairly good agreements were observed between the 3-D FEM and the measured results for strains. Therefore, for the joint strength, the results remain conservative.
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stress analysis and strength evaluation of Scarf adhesive joints subjected to static tensile loadings
International Journal of Adhesion and Adhesives, 2010Co-Authors: Dan He, Takeshi Iwamoto, Toshiyuki Sawa, Yuya HirayamaAbstract:Abstract The stress distributions in Scarf adhesive joints under static tensile loadings are analyzed using three-dimensional finite-element calculations. The effects of adhesive Young’s modulus, adhesive thickness and Scarf Angle in the adherend on the interface stress distributions are examined. As the results, it is found that the maximum value of the maximum principal stress occurs at the edge of the interfaces. The differences in the interface stress distributions between the 2-D and the 3-D FEM results are demonstrated. It is also observed from the 3-D FEM results that the maximum value of the maximum principal stress is the smallest when the Scarf Angle is around 60 degree, while it is around 52 degree in the 2-D FEM when the singular stress at the edges vanishes. In addition, the joint strength is estimated using the interface stress distribution obtained from the FEM calculations. For verification of the FEM calculations, experiments were carried out to measure the strengths and the strains in the joints under static tensile loadings using strain gauges. Fairly good agreements were observed between the 3-D FEM and the measured results for strains. Therefore, for the joint strength, the results remain conservative.
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a stress analysis and strength evaluation of Scarf adhesive joints subjected to static tensile loading
American Society of Mechanical Engineers Design Engineering Division (Publication) DE, 2006Co-Authors: Toshiyuki Sawa, Masahiro Sasaki, Yuya HirayamaAbstract:Scarf adhesive joints used in practice. However, the stress distributions and the joints strengths have not yet been fully elucidate. Important issues are how to determine the Scarf Angle in adherend and how to determine the adhesive properties. In this study, the stress distributions in Scarf adhesive joints under static tensile loadings are analyzed using three-dimensional finite-element calculations. In the FEM calculations, the effects of Young's modulus of the adhesive, adhesive thickness, Scarf Angle of the adherend on the stress distributions at the adhesive interfaces are examined. The maximum principal stresses were calculated at every element at the interfaces. As the results, it is found that the maximum value of the maximum principal stress occurs at the edge of the adhesive interfaces (z=0, 1/s=1). It is also observed that the maximum value of the stress is the smallest, when the Scarf Angle is 60 degree. In addition, the joint strength is estimated using the interface stress. For the verification of the FEM calculations, the experiments were carried out to measure the strengths and the strains in the joints under static tensile loadings using strain gauges. Fairly good agreements are observed between the numerical and the measured results concerning the joint strength and the strains.Copyright © 2006 by ASME
