FEM Stress Analysis and Strength of Scarf Adhesive Joints of Similar Adherend Subjected to Impact Tensile Loadings

Author(s):  
Toshiyuki Sawa ◽  
Yuya Hirayama ◽  
He Dan

The stress wave propagation and stress distribution in scarf adhesive joints have been analyzed using three-dimensional finite element method (FEM). The FEM code employed was LS-DYNA. An impact tensile loading was applied to the joint by dropping a weight. The effect of the scarf angle, Young’s modulus of the adhesive and adhesive thickness on the stress wave propagations and stress distributions at the interfaces have been examined. As the results, it was found that the point where the maximum principal stress becomes maximum changes between 52 degree and 60 degree under impact tensile loadings. The maximum value of the maximum principal stress increases as scarf angle decreases, Young’s modulus of the adhesive increases and adhesive thickness increases. In addition, Experiments to measure the strains and joint strengths were compared with the calculated results. The calculated results were in fairly good agreements with the experimental results.

1999 ◽  
Author(s):  
Jyo Shimura ◽  
Izumi Higuchi ◽  
Toshiyuki Sawa

Abstract The stress behavior in adhesive laminated cantilever beams subjected to impact loadings is analyzed using three-dimensional finite-element method (FEM) in the elastic region. The stress wave propagation and the stress distribution at the interfaces are examined. The effects of Young’s modulus of adherends, adhesive, the adherend thickness and the number of layers on the stress wave propagation at the interfaces are clarified. The following results are obtained. The maximum principal stress (σ1) is maximal at the adhesive interfaces. It is found that the maximum principal stress (σ1) at the adhesive interface increases as the Young’s modulus of the upper adherends increases. The maximum principal stress (σ1) at the adhesive interface increases as Young’s modulus of the adhesive increases. The maximum principal stress (σ1) at the adhesive interface decreases as the thickness of the adherend to which an impact load is applied increases. It is seen that the maximum principal stress (σ1) increases as number of layers increases. Experiments were carried out to measure the strain response of adhesive laminated cantilever beam using strain gauges. A fairly good agreement is seen between the analytical and experimental results.


2002 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Yoshihito Suzuki ◽  
Shoichi Kido

The stress variations in butt adhesive joints of dissimilar hollow cylinders under impact tensile loadings are analyzed in elastic and elasto-plastic deformation using a finite element method. The FEM code employed is DYNA3D. The effect of Young’s modulus of the adhesive, adhesive thickness and the inside diameter of the hollow cylinders and Young’s modulus ratio between dissimilar adherends on the stress variations at the interfaces are examined. In addition, a process in rupture at the interface of the joint is analyzed. The stress distributions in the joints under static loadings are also analyzed by an FEM. The characteristics of the stress variations in the joints under impact loadings are compared with those in the joints under the static loadings. Also, the joint strenths under impact loadings are estimated. As the results, it is found that the maximum value of the maximum principal stress σl occurs at the outside of the interface. It is also found that the maximum principal stress σl at the interface decreases as the inside diameter of the hollow cylinders increases. The characteristics of the joints subjected to the impact loadings are found to be opposite to those subjected to the static loadings. In addition, the experiments were carried out to measure the strain response of the butt adhesive joints under impact tensile loads using strain gauges. Furthermore, the joint strengths under impact loadings were measured. Fairly good agreements are observed between the numerical and the measured results.


2000 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Takahiro Ohmori

Abstract The stress wave propagation and the stress distribution in stepped-lap adhesive joints of similar adherends subjected to impact tensile loads and elastic deformation are analyzed using three-dimensional finite-element method (FEM). The impact load is applied to the joint by dropping a weight. One end of the upper adherend is fixed, and the other end of the lower adherend is subjected to an impact load. FEM code employed is DYNA3D. The effects of Young’s modulus of the adherends, the number of lapped steps, and the adhesive thickness on the stress wave propagation at the lapped, and fee butted interfaces are examined. It is also found that the maximum value of the maximum principal stress σ1 occurs at the end of the butted interface between the adhesive and the lower adherend to which the impact load is applied. As the number of the lapped steps increases, the maximum value of the maximum principal stress σ1 increases. It is found that the maximum value of the maximum principal stress σ1 increases as the adhesive thickness decreases. The maximum value of σ1 increases as Young’s modulus of the adherends increases. In addition, the experiments were carried out to measure the strain response of stepped-lap adhesive joints subjected to impact tensile loads using strain gauges. A fairly good agreement is seen between the analytical, and the experimental results.


Author(s):  
Toshiyuki Sawa ◽  
Kohei Ichikawa

The stress variations and stress distributions in stepped-lap adhesive joints of dissimilar adherends under impact tensile loadings were analyzed in elastic range using three-dimensional finite element method. The impact loadings were applied to the lower adherend by dropping a weight. The stress distributions in stepped-lap adhesive joints of dissimilar adherends under static tensile loadings were also analyzed using FEM. The effects of Young’s modulus of the adherends, the adhesive thickness and the number of butted steps of adherents ware examined under both impact and static loadings. As the results, The maximum value of stress σ1 increased as Young’s modulus of the adherends increased for the impact loadings. The maximum value of stress σ1 increased as the numbers of steps in the adherends increased for the static loadings. In addition, the experiments to measure the strain response of joints subjected to impact tensile loadings were carried out using strain gauges. A fairly good agreement was found between the numerical and the measured results concerning the strain responses.


Author(s):  
Toshiyuki Sawa ◽  
Masahiro Sasaki

The stress variations and stress distributions in scarf and stepped-lap adhesive joints of similar adherends under static and impact tensile loadings were analyzed in elastic range using three-dimensional finite element method. The impact loadings were applied to the lower adherend by dropping a weight. The stress distributions in scarf adhesive joints of similar adherends under static tensile loadings were also analyzed using FEM. The effects of Young’s modulus of the adherends, the adhesive thickness, and the angle of the adherends on the stress distributions at the interfaces between the adherends and the adhesive were examined under static loadings. The maximum value of σ1 decreased as young’s modulus of the adhesive increased in the stepped-lap adhesive joints under static loadings. However, the result of the scarf adhesive joints under static loadings was opposite to the above result. The value of σ1 became minimum when the scarf angle was 52°in the scarf adhesive joint. In addition, the experiments to measure the strain response and strain of joints subjected to impact and static tensile loadings were carried out using strain gauges. Fairly good agreements ware found between the numerical and the measured results.


Author(s):  
Toshiyuki Sawa ◽  
Masahiro Sasaki ◽  
Yuya Hirayama

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.


Author(s):  
Toshiyuki Sawa ◽  
Atsushi Karami

The stress distributions in scarf adhesive joints of dissimilar adherends under static bending moments are analyzed using three-dimensional finite-element calculations. The code employed is ANSYS. In 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 interface are examined. As the results, it is found that the maximum value of the maximum principal stress occurs at the edge of the scarf adhesive interface. It is also observed that the maximum value of the stress is minimum, when the scarf angle is 60 degree. In addition, the joint strength is estimated using the obtained stress distribution. For the verification of the FEM calculations, the experiments were carried out to measure the strengths and the strains in the joints under static bending moments using strain gauges. Fairly good agreements are observed between the numerical and the measured results concerning the joint strength and the strains.


2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 194-200
Author(s):  
Yakup Kantaci ◽  
Sabiha Zelal Ülkü

Aim: To evaluate the stress distribution in the cortical bone under parafunctional forces with different occlusal thicknesses, monolithic zirconia with different implant diameters, and number variations in implant-supported fixed prosthetic restorations applied in patients with bruxism. Methodology: The tomographic sections of the previously registered mandible were used in order to model the mandible. Modeled bone height is 30 mm, cortical bone thickness is 1.5 mm, and trabecular bone thickness is modeled as 13 mm. By placing two implants in the created bone model, a three-member main model (Group 1), the number of implants was increased, three implants supported the Group 2 models, the diameter of the implants was increased, and the Group 3 models were created. The created Group 1, 2, 3 models, the occlusal thickness was divided into subgroups with 1.0, 1.5, and 2.0 mm, respectively (Groups A, B, and C). The groups were applied in two directions: vertical and 30o oblique. Stress values under forces were analyzed by finite element stress analysis. Results: Under vertical loading, the maximum principal stress value in the cortical bone was found to be lowest in Group 2C, and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be the lowest in Group 3C, and the highest minimum principal stress value was found in Group 1A. Under oblique loading, the maximum principal stress value in the cortical bone was found to be the lowest in Group 3C and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be lowest in Group 3C, and the highest minimum principal stress value was found in Group1A. Conclusion: Stresses caused by oblique forces are more than vertical forces. Increasing the occlusal thickness of the implant fixed prosthesis material, implant diameter, and number reduce the minimum and maximum principal stress values in the cortical   How to cite this article: Kantaci Y, Ülkü SZ. Evaluation of the stress distribution in the cortical bone caused by variations in implant applications in patients with bruxism: A three-dimensional finite element analysis. Int Dent Res 2021;11(Suppl.1):194-200. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.27   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.


2011 ◽  
Vol 130-134 ◽  
pp. 1495-1498 ◽  
Author(s):  
Xiao Cong He

The aim of this paper is to investigate the effect of supports on the actual stress distribution of the single-lap adhesive joints under tension using the three-dimensional finite element methods. Five layers of elements were used across the adhesive thickness in order to obtain an accurate indication of the variation of stresses. All the numerical results obtained from the finite element analysis show that the spatial distribution of all components of stress are similar for different interfaces though the stress values are obviously different. The results also show that most of the maximum stresses occur at the interface 1. It can be seen from the results that the stresses are concentrated near the left free ends of the adhesive layer while the centre region of the adhesive layer is mostly stress-free.


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