Finite Element Analysis on the Influence of Back-Up Ring on the Sealing Effect of Rubber O-Ring

2011 ◽  
Vol 199-200 ◽  
pp. 1595-1599
Author(s):  
Dian Xin Li ◽  
Hong Lin Zhao ◽  
Shi Min Zhang ◽  
Chang Run Wu ◽  
Xian Long Liu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Service Life ◽  
Contact Pressure ◽  
Von Mises Stress ◽  
Analysis Software ◽  
Element Analysis ◽  
Von Mises ◽  
The Right

Based on finite element analysis software ANSYS, the deformation and force condition of the rubber sealing o-ring pre and post with back-up ring under different oil pressure conditions was analyzed. The von mises stress distribution of the o-ring and the change of contact pressure between o-ring and sealing interface pre and post with back-up ring under different oil pressure conditions were discussed. The results show that, the maximum von mises stress of the o-ring is smaller and the maximum von mises stress of the sealing system concentrates on the left top and the right bottom of the back-up ring after using it; the o-ring will not be extruded into the gap of the groove because of the existence of back-up ring which prevents gap-bite and prolongs service life of the o-ring; the contact pressure between o-ring and sealing interface increased, thus the sealing reliability of the system increased.

The function(s) of bone ornamentation in the crocodylomorph osteoderms: a biomechanical model based on a finite element analysis

Paleobiology ◽  
2019 ◽  
Vol 45 (1) ◽  
pp. 182-200 ◽  
Author(s):  
François Clarac ◽  
Florent Goussard ◽  
Vivian de Buffrénil ◽  
Vittorio Sansalone
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Von Mises Stress ◽  
Late Triassic ◽  
Mechanical Resistance ◽  
Apical Surface ◽  
Element Analysis ◽  
Physiological Functions ◽  
Von Mises

AbstractThis paper aims at assessing the influence of the bone ornamentation and, specifically, the associated loss of bone mass on the mechanical response of the crocodylomorph osteoderms. To this end, we have performed three-dimensional (3D) modeling and a finite element analysis on a sample that includes both extant dry bones and well-preserved fossils tracing back to the Late Triassic. We simulated an external attack under various angles on the apical surface of each osteoderm and further repeated the simulation on an equivalent set of smoothed 3D-modeled osteoderms. The comparative results indicated that the presence of an apical sculpture has no significant influence on the von Mises stress distribution in the osteoderm volume, although it produces a slight increase in its numerical score. Moreover, performing parametric analyses, we showed that the Young's modulus of the osteoderm, which may vary depending on the bone porosity, the collagen fiber orientation, or the calcification density, has no impact on the von Mises stress distribution inside the osteoderm volume. As the crocodylomorph bone ornamentation is continuously remodeled by pit resorption and secondary bone deposition, we assume that the apical sculpture may be the outcome of a trade-off between the bone mechanical resistance and the involvement in physiological functions. These physiological functions are indeed based on the setup of a bone superficial vessel network and/or the recurrent release of mineral elements into the plasma: heat transfers during basking and respiratory acidosis buffering during prolonged apnea in neosuchians and teleosaurids; compensatory homeostasis in response to general calcium deficiencies. On a general morphological basis, the osteoderm geometric variability within our sample leads us to assess that the global osteoderm geometry (whether square or rectangular) does not influence the von Mises stress, whereas the presence of a dorsal keel would somewhat reduce the stress along the vertical axis.

Stresses in Teeth and Overlying Crowns

2012 ◽  
Vol 457-458 ◽  
pp. 567-571
Author(s):  
Liliana Sandu ◽  
Florin Topală ◽  
Sorin Porojan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Numerical Simulations ◽  
Experimental Model ◽  
3D Scanning ◽  
Analysis Software ◽  
Element Analysis ◽  
Equivalent Stresses ◽  
Von Mises

A complete cast crown allows the operator to modify axial tooth contour. The margin should be smooth and distinct and its width has to allow adequate bulk of metal at the margin. The objective of this study was to evaluate, by finite element analysis, the influence of different degree of taper and marginal designs for cast crown preparations, on the stress distribution in teeth and crowns. As experimental model an upper first molar was used. The geometry of the intact tooth were obtained by 3D scanning. The tooth preparations and the complete cast crowns were designed. Models were exported in a finite element analysis software for structural simulations. Von Mises equivalent stresses were calculated and their distribution was plotted graphically. Numerical simulations provide a biomechanical explanation for stress distribution in prepared teeth and overlying crowns.

scholarly journals The Influence of Pelvic Tilt on Stress Distribution in the Acetabulum: Finite Element Analysis

2020 ◽  
Author(s):  
Kazuhiro Hasegawa ◽  
Tamon Kabata ◽  
Yoshitomo Kajino ◽  
Daisuke Inoue ◽  
Jiro Sakamoto ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Hip Joint ◽  
Tilt Angle ◽  
Pelvic Tilt ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Von Mises

Abstract Background Finite element analysis (FEA) has been previously applied for the biomechanical analysis of acetabular dysplasia and osteotomy. However, until now, there have been little reports on the use of FEA to evaluate the effects of pelvic tilt on stress distribution in the acetabulum. Methods We used the Mechanical Finder Ver. 7.0 (RCCM, Inc., Japan) to construct finite element models based on 3D-CT data of patients, and designed dysplasia, borderline, and normal pelvic models. For analysis, body weight was placed on the sacrum and the load of the flexor muscles of the hip joint was placed on the ilium. The pelvic tilt was based on the anterior pelvic plane, and the pelvic tilt angles were -20°, 0°, and 20°. The load of the flexor muscle of the hip joint was calculated using the moment arm equation.Results All three models showed the highest values of von Mises stress in the -20° pelvic tilt angle, and the lowest in the 20° angle. Stress distribution concentrated in the load-bearing area. The maximum values of von Mises stress in the borderline at pelvic tilt angles of -20° was 3.5Mpa, and in the dysplasia at pelvic tilt angles of 0° was 3.1Mpa. Conclusions The pelvic tilt angle of -20° of the borderline model showed equal maximum values of von Mises stress than the dysplasia model of pelvic tilt angle of 0°, indicating that pelvic retroversion of -20° in borderline is a risk factor for osteoarthritis of the hip joints, similar to dysplasia.

scholarly journals Evaluation of Stress Distribution and Force in External Hexagonal Implant: A 3-D Finite Element Analysis

2021 ◽  
Vol 18 (19) ◽  
pp. 10266
Author(s):  
Vinod Bandela ◽  
Ram Basany ◽  
Anil Kumar Nagarajappa ◽  
Sakeenabi Basha ◽  
Saraswathi Kanaparthi ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Axial Direction ◽  
Von Mises Stress ◽  
P Value ◽  
Implant Surface ◽  
Element Analysis ◽  
Von Mises

Purpose: To analyze the stress distribution and the direction of force in external hexagonal implant with crown in three different angulations. Materials and Methods: A total of 60 samples of geometric models were used to analyze von Mises stress and direction of force with 0-, 5-, and 10-degree lingual tilt. Von Mises stress and force distribution were evaluated at nodes of hard bone, and finite element analysis was performed using ANSYS 12.1 software. For calculating stress distribution and force, we categorized and labeled the groups as Implant A1, Implant A2, and Implant A3, and Implant B1, Implant B2, and Implant B3 with 0-, 5-, and 10-degree lingual inclinations, respectively. Inter- and intra-group comparisons were performed using ANOVA test. A p-value of ≤0.05 was considered statistically significant. Results: In all the three models, overall maximum stress was found in implant model A3 on the implant surface (86.61), and minimum was found on model A1 in hard bone (26.21). In all the three models, the direction of force along three planes was maximum in DX (0.01025) and minimum along DZ (0.002) direction with model B1. Conclusion: Maximum von Mises stress and the direction of force in axial direction was found at the maximum with the implant of 10 degrees angulation. Thus, it was evident that tilting of an implant influences the stress concentration and force in external hex implants.

scholarly journals Study of the Stress Distribution Around the Mini-implant During Maxillary Anterior Intrusion Under Different Conditions: A 3-Dimensional Finite Element Analysis

2020 ◽  
Vol 54 (2) ◽  
pp. 106-114
Author(s):  
Udita Thakkar ◽  
Neeraj S. Patil ◽  
Ajay P. Thakkar ◽  
Shrikant S. Chitko ◽  
Pratik Jaltare
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Root Resorption ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Deep Bite ◽  
Anterior Teeth ◽  
Dimensional Finite Element ◽  
Von Mises

Introduction: Correction of deep bite is one of the major challenges of orthodontic treatment. Mini-implants provide stable intra-oral anchorage and facilitate the maxillary incisors to be intruded without the usual side. The purpose of this finite element study was to evaluate the stress distribution around the mini-implant during maxillary anterior intrusion under different conditions of different angulations and different positions of implant. Material and Methods: Finite element analysis was carried out. Stress under the following 4 conditions was analyzed: (a) single central implant placed at 90°, (b) single central implant placed at 120°, (c) bilaterally placed implant at 90°, and (d) bilaterally placed implant at 120°. Results: The displacement seen with 90° angulation in the single implant case is less compared with the 120° angulation case for all the 6 maxillary anterior teeth. Also, in the bilateral implant case, the Von Mises stress is less when the 90° angulation case is compared to 120° angulation case. But in bilaterally placed implant, the stress gets distributed evenly in the anterior region. The stress in 90° angulation cases seems to be concentrated at the center. Conclusion: Stresses measured on the teeth are less and distributed more evenly when the point of force application is bilateral. It was also observed that the stress increases with increase in the angulation of the implant. As the contact between the implant and the bone increases, the stability increases. Hence, the implant should be obliquely inserted into the bone. Concentrated stresses are not favorable as they can increase the risk of bone and root resorption.

scholarly journals THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF CLASS 2 INLAY ON MANDIBULAR MOLAR USING VARIOUS MATERIALS

2018 ◽  
Vol 6 (7) ◽  
pp. 272-277
Author(s):  
Maj Pankaj Awasthi ◽  
Lt Col Sonali Sharma ◽  
Maj Summerdeep Kaur
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Stress Analysis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Tooth Structure ◽  
Mandibular Molar ◽  
Von Mises ◽  
Mandibular First Molar

Aim: To study the stress distribution in Class 2 Inlay of various materials on Mandibular Molar. Background: Inlays are fabricated using different materials like gold, porcelain or a cast metal alloy. Difference in the modulus of elasticity of the material and tooth structure would lead to generation of stresses leading to failure of the restoration or loss of tooth structure. Finite Element Analysis (FEA) is a mathematical tool for stress analysis in a structure. Von Mises stress being the combination of normal and shear stresses which occur in all directions. This stress has to be given diligent importance while considering the type and material of restoration to achieve long-term success. Methodology: In our study, stress analysis was performed on the mandibular first molar using a stress analysis software (ANSYS). A computer model of mandibular first molar was generated along with generation of an inlay volume using a FEA software preprocessor. The models with the class 2 inlays of different materials were subjected to 350N and 800N load simulating normal masticatory force and bruxism respectively. Maximum and minimum stresses were calculated for each model separately. Results: Von Mises stress distribution for different materials for normal masticatory forces and bruxism were studied and evaluated. Conclusion: The study revealed the maximum and minimum stresses imposed over the tooth and the restoration and provides insight into the areas which are more prone to fracture under the occlusal load.

scholarly journals A deep learning approach to estimate stress distribution: a fast and accurate surrogate of finite-element analysis

2018 ◽  
Vol 15 (138) ◽  
pp. 20170844 ◽  
Author(s):  
Liang Liang ◽  
Minliang Liu ◽  
Caitlin Martin ◽  
Wei Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Deep Learning ◽  
Stress Distribution ◽  
Machine Learning Techniques ◽  
Von Mises Stress ◽  
Patient Specific ◽  
Stress Distributions ◽  
Element Analysis ◽  
Von Mises

Structural finite-element analysis (FEA) has been widely used to study the biomechanics of human tissues and organs, as well as tissue–medical device interactions, and treatment strategies. However, patient-specific FEA models usually require complex procedures to set up and long computing times to obtain final simulation results, preventing prompt feedback to clinicians in time-sensitive clinical applications. In this study, by using machine learning techniques, we developed a deep learning (DL) model to directly estimate the stress distributions of the aorta. The DL model was designed and trained to take the input of FEA and directly output the aortic wall stress distributions, bypassing the FEA calculation process. The trained DL model is capable of predicting the stress distributions with average errors of 0.492% and 0.891% in the Von Mises stress distribution and peak Von Mises stress, respectively. This study marks, to our knowledge, the first study that demonstrates the feasibility and great potential of using the DL technique as a fast and accurate surrogate of FEA for stress analysis.

scholarly journals Stress Distribution on the Prosthetic Screws in the All-on-4 Concept: A Three-Dimensional Finite Element Analysis

2020 ◽  
Vol 46 (1) ◽  
pp. 3-12
Author(s):  
Ji-Hyeon Oh ◽  
Young-Seong Kim ◽  
Joong Yeon Lim ◽  
Byung-Ho Choi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Edentulous Patients ◽  
Von Mises ◽  
Three Dimensional Finite Element

The all-on-4 concept, which is used to rehabilitate edentulous patients, can present with mechanical complications such as screw loosening and fracture. The purpose of this study was to evaluate the stress patterns induced in the prosthetic screws by the different prosthetic screw and abutment designs in the all-on-4 concept using finite element analysis. Von Mises stress values on 6 groups of each screw type, including short and narrow screw, short abutment; short and wide screw, short abutment; long and wide screw, short abutment; short and narrow screw, long abutment; short and wide screw, long abutment; and long and wide screw, long abutment, were compared under a cantilever loading of 200 N that was applied on the farther posterior to the position of the connection between the distal implant and the metal framework. Posterior prosthetic screws showed higher stress values than anterior prosthetic screws. The stress values in posterior prosthetic screws decreased as the length and diameter increased. In conclusion, the long and wide screw design offers advantages in stress distribution when compared with the short and narrow design.

Finite Element Analysis of Contact and Structural Phenomena of a Lab-Scale Electromagnetic Accelerator

2007 ◽  
Author(s):  
Bummo Chung ◽  
Itzhak Green ◽  
Richard S. Cowan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Pressure ◽  
Contact Area ◽  
Von Mises Stress ◽  
Mode Shapes ◽  
Element Analysis ◽  
Vibrational Characteristics ◽  
Von Mises ◽  
Electromagnetic Accelerator

This work presents a finite element analysis (FEA) of the initial armature-to-rail contact of a lab-scale electromagnetic accelerator (12.5 mm rail height) and a modal analysis of the armature. Structural results of the von Mises stress, the contact pressure, and the contact area are presented with the vibrational characteristics (frequencies and mode shapes) of the un-stressed and the pre-stressed armature.

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