A three-dimensional stress distribution problem in the anchorage zone of a post-tensioned concrete beam

1966 ◽  
Vol 18 (55) ◽  
pp. 75-84 ◽  
Author(s):  
K. T. Sundara Raja Iyengar ◽  
C. V. Yogananda
2021 ◽  
Vol 11 (3) ◽  
pp. 1220
Author(s):  
Azeem Ul Yaqin Syed ◽  
Dinesh Rokaya ◽  
Shirin Shahrbaf ◽  
Nicolas Martin

The effect of a restored machined hybrid dental ceramic crown–tooth complex is not well understood. This study was conducted to determine the effect of the stress state of the machined hybrid dental ceramic crown using three-dimensional finite element analysis. Human premolars were prepared to receive full coverage crowns and restored with machined hybrid dental ceramic crowns using the resin cement. Then, the teeth were digitized using micro-computed tomography and the teeth were scanned with an optical intraoral scanner using an intraoral scanner. Three-dimensional digital models were generated using an interactive image processing software for the restored tooth complex. The generated models were imported into a finite element analysis software with all degrees of freedom concentrated on the outer surface of the root of the crown–tooth complex. To simulate average occlusal load subjected on a premolar a total load of 300 N was applied, 150 N at a buccal incline of the palatal cusp, and palatal incline of the buccal cusp. The von Mises stresses were calculated for the crown–tooth complex under simulated load application was determined. Three-dimensional finite element analysis showed that the stress distribution was more in the dentine and least in the cement. For the cement layer, the stresses were more concentrated on the buccal cusp tip. In dentine, stress was more on the cusp tips and coronal 1/3 of the root surface. The conventional crown preparation is a suitable option for machined polymer crowns with less stress distribution within the crown–tooth complex and can be a good aesthetic replacement in the posterior region. Enamic crowns are a good viable option in the posterior region.


2007 ◽  
Vol 345-346 ◽  
pp. 1469-1472
Author(s):  
Gab Chul Jang ◽  
Kyong Ho Chang ◽  
Chin Hyung Lee

During manufacturing the welded joint of steel structures, residual stress is produced and weld metal is used inevitably. And residual stress and weld metal influence on the static and dynamic mechanical behavior of steel structures. Therefore, to predict the mechanical behavior of steel pile with a welded joint during static and dynamic deformation, the research on the influence of the welded joints on the static and dynamic behavior of steel pile is clarified. In this paper, the residual stress distribution in a welded joint of steel piles was investigated by using three-dimensional welding analysis. The static and dynamic mechanical behavior of steel piles with a welded joint is investigated by three-dimensional elastic-plastic finite element analysis using a proposed dynamic hysteresis model. Numerical analyses of the steel pile with a welded joint were compared to that without a welded joint with respect to load carrying capacity and residual stress distribution. The influence of the welded joint on the mechanical behavior of steel piles during static and dynamic deformation was clarified by comparing analytical results


2021 ◽  
pp. 030157422097434
Author(s):  
V Sandhya ◽  
AV Arun ◽  
Vinay P Reddy ◽  
S Mahendra ◽  
BS Chandrashekar ◽  
...  

Background and Objectives: This study was conducted to determine the effective method to torque the incisor with thermoplastic aligner using a three-dimensional (3D) finite element method. Materials and Methods: Three finite element models of maxilla and maxillary dentition were developed. In the first model, thermoplastic aligner without any auxiliaries was used. In the second and third models, thermoplastic aligner with horizontal ellipsoid composite attachment and power ridge were used, respectively. The software used for the study was ANSYS 14.5 FE. A force of 100 g was applied to torque the upper right central incisor. The resultant force transfer, stress distribution, and tooth displacement were evaluated. Results: The overall tooth displacement and stress distribution appeared high in the model with power ridge, whereas the root movement was more in the horizontal ellipsoid composite attachment model. The model without any auxillaries produced least root movement and stress distribution. Conclusion: Horizontal ellipsoid composite attachment achieved better torque of central incisor than the model with power ridge and model without any auxillaries.


Author(s):  
M Taylor ◽  
E W Abel

The difficulty of achieving good distal contact between a cementless hip endoprosthesis and the femur is well established. This finite element study investigates the effect on the stress distribution within the femur due to varying lengths of distal gap. Three-dimensional anatomical models of two different sized femurs were generated, based upon computer tomograph scans of two cadaveric specimens. A further six models were derived from each original model, with distal gaps varying from 10 to 60 mm in length. The resulting stress distributions within these were compared to the uniform contact models. The extent to which femoral geometry was an influencing factor on the stress distribution within the bone was also studied. Lack of distal contact with the prosthesis was found not to affect the proximal stress distribution within the femur, for distal gap lengths of up to 60 mm. In the region of no distal contact, the stress within the femur was at normal physiological levels associated with the applied loading and boundary conditions. The femoral geometry was found to have little influence on the stress distribution within the cortical bone. Although localized variations were noted, both femurs exhibited the same general stress distribution pattern.


1983 ◽  
Vol 105 (3) ◽  
pp. 268-274 ◽  
Author(s):  
C. J. Chuong ◽  
Y. C. Fung

A three-dimensional stress-strain relationship derived from a strain energy function of the exponential form is proposed for the arterial wall. The material constants are identified from experimental data on rabbit arteries subjected to inflation and longitudinal stretch in the physiological range. The objectives are: 1) to show that such a procedure is feasible and practical, and 2) to call attention to the very large variations in stresses and strains across the vessel wall under the assumptions that the tissue is incompressible and stress-free when all external load is removed.


2008 ◽  
Vol 575-578 ◽  
pp. 449-454
Author(s):  
Chu Yun Huang ◽  
Sai Yu Wang ◽  
Tao Yang ◽  
Xu Dong Yan

The stress fields of rectangular and T shape compression dies were simulated by three dimensional photo-elasticity of stress freezing method. The rules of stress distribution of σx, σy, σz on the surface of rectangular and T-shaped dies were discovered, and the rules were also found inside the dies. The results indicate that the stress distribution of rectangular die is similar to that of T shape die. Obvious stress concentration in corner of die hole was observed. σz rises from die hole to periphery until it achieves maximum value then it diminishes gradually, and σz between die hole and fix diameter zone is higher than it is in other position. At the same time, the equations of stress field of extrusion dies were obtained by curved surface fitting experimental values in every observed point with multiple-unit regression analysis method and orthogonal transforms. These works can provide stress distribution model for die computer aided design and make.


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