scholarly journals Steel I-joists calculating method with the heel joint partial restraint

2020 ◽  
Vol 7 (3) ◽  
Author(s):  
Dmitry Kuznetsov ◽  
Svetlana Belyaeva ◽  
Vitaliy Sazykin
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Numerical Models ◽  
Tensile Force ◽  
Three Dimensional ◽  
Numerical Calculations ◽  
Test Models ◽  
Flexural Member ◽  
Strain Stress ◽  
Three Dimensional Finite Element

Steel joists in general, are widely used in modern building practice and I-joist systems in particular. That is why close attention to the structural concept development or joist construction is paid. That would significantly reduce the material consumption, including changing the flexural member strain-stress distribution. The classic pin joint for supporting steel joist involves a bolted connection in the lower third of the knife-edge height. The constructive solution considered in this article contains additional requirements for the heel joint: tight installation clearance filling between two adjacent joist knife-edges, bolt installation that satisfy the strength condition. These requirements ensure the tensile force transfer from a couple of forces emerging on the pier. We proposed a method for calculating steel I-joist, with the account of the obtained partial restraint effect. This method developed based on numerical calculations of three-dimensional finite element beams models using the binodal unilateral connection, however, with proper justification, the results transfer to the core design schemes. Modeling and calculations are performed in the SCAD Office computer complex. The steel I-joist floor beams studied in this paper have 15 m spans. The restraining effect is estimated based on a results comparison of finite element models numerical calculations of a single joist and two adjacent simultaneously working steel joists. Joist test models are made using shell finite elements with zero Gaussian curvature. As the study result of the operation compatibility of the joist structures heel joint and the analysis of the system strain-stress distribution, a moment redistribution from the span to the heel joint was revealed. With the increase in the span, the restrain effect was found fading. The partial restrain accounting method allows us to assign more economical sections during similar structures designing, due to the introduction of binodal unilateral connection in the heel joint of the joist numerical models. This technique can be used for verification calculations during the technical examination. This paper shows that the bolt junction sections selection for connecting steel joists on a pier can be performed according to the reactions obtained in unilateral connection. Using this calculation methodology in practice for actual construction design provides an opportunity to increase the joist systems’ efficiency and reliability that part of constructional buildings and structures complex.

scholarly journals Three-Dimensional Finite Element Analysis of Stress Distribution in a Tooth Restored with Full Coverage Machined Polymer Crown

2021 ◽  
Vol 11 (3) ◽  
pp. 1220
Author(s):  
Azeem Ul Yaqin Syed ◽  
Dinesh Rokaya ◽  
Shirin Shahrbaf ◽  
Nicolas Martin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Intraoral Scanner ◽  
Element Analysis ◽  
Dental Ceramic ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Ceramic Crown

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.

scholarly journals Biomechanical Effects of Torquing on Upper Central Incisor with Thermoplastic Aligner: A Comparative Three-Dimensional Finite Element Study with and Without Auxillaries

2021 ◽  
pp. 030157422097434
Author(s):  
V Sandhya ◽  
AV Arun ◽  
Vinay P Reddy ◽  
S Mahendra ◽  
BS Chandrashekar ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Central Incisor ◽  
Dimensional Finite Element ◽  
Attachment Model ◽  
Three Dimensional Finite Element ◽  
3D Finite Element Method ◽  
Root Movement ◽  
Maxillary Dentition

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.

Three-dimensional finite element analysis comparative model of tooth–implant nonrigid fixation

SIMULATION ◽  
2020 ◽  
pp. 003754972097278
Author(s):  
Tigran A Muradyan ◽  
Nshan A Muradyan ◽  
Sergey V Verlinski ◽  
Anna Yu Poghosyan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Rigid Fixation ◽  
Element Analysis ◽  
Validation Data ◽  
Vertical Loading ◽  
N Loading ◽  
Three Dimensional Finite Element

Connecting implants with teeth is sometimes considered for the support of prostheses in partial edentulism, especially in periodontally compromised and surgical treated patients. The aim of this study is the presentation of a model of tooth–implant nonrigid fixation in comparison with implant–implant and implant–tooth rigid fixation by three-dimensional (3D) finite element analysis. As a model, a situation with a mandibular second premolar and two molars edentulism was selected. Two implantation options with three prosthetics designs were considered. The comparative analysis of stress and strain distribution values under vertical 100 and 200 N loading was performed. The highest peri-implant crestal bone stress distribution was observed in the model with the implant–tooth rigid fixation with 200 N vertical loading with results of 136.56 MPa. In the model with implant–tooth nonrigid fixation, the maximum strain value was observed in the tooth–connector zone and the stress distribution was higher in the connectors and the prosthesis pontic zone, with a maximal value of 27.77 MPa. The design of a tooth–implant fixed denture could be suggested as a method of choice for rehabilitation of the posterior edentulous segment in cases when only one distal implant could be installed. Further clinical research is required to obtain reliable validation data for the proposed method.

scholarly journals A Comparative Three-Dimensional Finite Element Study of Two Space Regainers in the Mixed Dentition Stage

2020 ◽  
Vol 14 (01) ◽  
pp. 107-114
Author(s):  
Mohamed Ahmed Abdel Hakim ◽  
Nagwa Mohamed Ali Khatab ◽  
Kareem Maher Gaber Mohamed ◽  
Ahmad Abdel Hamid Elheeny
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
The Other ◽  
Mixed Dentition ◽  
Von Mises Stress ◽  
Stress Concentrations ◽  
Permanent Molar ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Abstract Objectives This study aims to compare the stress distribution and displacement that resulted from the use of a Gerber space regainer and sagittal distalizer using three-dimensional finite element analysis. Materials and Methods Three-dimensional simulated models of the appliances were developed using a software. The forces applied by the two appliances were 3N (tipping) and 15N (bodily), respectively. Displacement and von Mises stress on the compact and cancellous bone, periodontal ligament (PDL), crowns of the mandibular first, second permanent molars, and deciduous canines were calculated. Stress distribution and displacement values were measured via linear static analysis. Results Gerber space regainer showed greater displacement than that produced by the sagittal distalizer at the first permanent molar. However, such displacement was less at the other tested points when compared with that delivered by sagittal distalizer. The stresses created by Gerber appliance were higher in the crown and PDL of the deciduous canine than the crown of the first permanent molar crown. Conclusions Gerber appliance generates more distal force and less stress concentration on the crown of the mandibular first permanent molar than that created by the sagittal distalizer. On the other hand, stress concentrations produced by Gerber space regainer are found to be more on the crown and PDL of the deciduous canine. Therefore, it can be concluded that the use of Gerber appliance needs more anchorage.

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