The Effect of Nanoparticles (n-HAp, n-TiO2) on the Thermal Properties and Biomechanical Analysis of Polymeric Composite Materials for Dental Applications

2021 ◽  
Vol 33 ◽  
pp. 13-34
Author(s):  
Alaa A. Mohammed ◽  
Jawad K. Oleiwi ◽  
Emad S. Al-Hassani
Keyword(s):  
Thermal Properties ◽  
Composite Materials ◽  
Safety Factor ◽  
Polymeric Composite ◽  
Weight Fraction ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Total Deformation ◽  
Scanning Calorimetry ◽  
Element Analysis

Polyetheretherketone (PEEK), as implants is broadly employed in orthopedic and dental uses owing to the brilliant chemical stability, biocompatibility and mechanical strength in addition to the modulus of elasticity alike the human bone. In the present work, the composite materials with PEEK as matrix and (n-HAp, n-TiO2) as the reinforced fillers loaded up to (1.5 wt%) were prepared by internal mixer and hot press. Following analysis by physical properties includes the thermal conductivity and the differential scanning calorimetry. Finite element analysis (FEA) was used to find the total deformation, Max. Von mises stress, elastic strain and safety factor. The results manifested that the thermal properties, total deformation and strain decreased with the increase of the reinforcement weight fraction, while, the stress and safety factor increased with the increased reinforcement weight fraction.

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.

New Triaxial Connection Safety Factor for Tubular Design

2021 ◽  
pp. 1-11
Author(s):  
Malcolm A. Goodman
Keyword(s):  
Finite Element Analysis ◽  
Safety Factor ◽  
American Petroleum Institute ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Threaded Connections ◽  
Shear Component ◽  
Physical Tests ◽  
The Mean ◽  
Von Mises

Summary The American Petroleum Institute (API) equation for internal leak of API connections is uniaxial because it ignores axial force and external backup pressure. The ISO 13679 (2002) standard for qualification of premium connections is biaxial at best. It includes tension/compression but ignores backup pressure for both internal and external leak tests. For tubular design, this paper introduces a new fully triaxial safety factor for threaded connections with dependence on thread shear and hydrostatic pressure. Triaxial hydrostatic behavior is modeled with the mean normal stress, and thread shear behavior is modeled with the shear component of the von Mises stress. A leak line for use like the pipe body ellipse is proposed for quick leak assessment. Leak ratings and correlation with finite element analysis (FEA) results are presented for an example case of a 7-in.35-ppf N80 long-thread-casing (LTC) connection. The new triaxial safety factor with two connection constants applies to all types of threaded connections, including tubing, casing, and drillpipe, so long as the two constants are evaluated with appropriate but simple physical tests.

Design Optimisation and Analysis of a Quadrotor Arm Using Finite Element Method

2014 ◽  
Vol 664 ◽  
pp. 371-375
Author(s):  
Vishank Bhatia ◽  
R. Karthikeyan ◽  
R.K. Ganesh Ram ◽  
Yashaan Nari Cooper
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Optimization ◽  
Gravitational Force ◽  
Von Mises Stress ◽  
Structural Elements ◽  
Total Deformation ◽  
Element Analysis ◽  
Von Mises ◽  
Ansys Workbench

The structural analysis of quad rotor frame is important since it has to withstand the forces due to aerodynamics and gravitational force due to the mounted weights. Design optimization based on finite element analysis provides an efficient methodology to meet the desired objectives related to structural elements. In the present study, design optimization based on response surface methodology has been used to optimize the shape of the arm used in the quad rotor. The objectives considered for the study include minimization of Von Mises stress and total deformation. The goal driven optimization used in ANSYS WORKBENCH has been employed for the study and arm has been redesigned to meet the set goals.

N,N′-Bis(benzoyl) adipic acid dihydrazide and talc: nucleating agents for poly(l-lactic acid)

2016 ◽  
Vol 36 (4) ◽  
pp. 381-390 ◽  
Author(s):  
Bai Xue ◽  
Dan Guo ◽  
Jianjun Bao
Keyword(s):  
Lactic Acid ◽  
Adipic Acid ◽  
Polymeric Composite ◽  
Weight Fraction ◽  
Nucleating Agent ◽  
High Heat ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Heat Distortion Temperature ◽  
Composite Samples

Abstract In this paper, high-heat-resistant polymeric composite products were prepared via the traditional melt blending process by incorporating N,N′-bis(benzoyl) adipic acid dihydrazide (BAAD) into poly(l-lactic acid) (PLLA), which acted as an organic nucleating agent. The heat distortion temperature (HDT) of the PLLA/BAAD composite samples was measured by an HDT apparatus, and a high value of 96.2°C was achieved at a BAAD loading fraction of 0.5 wt.%, whereas, at the same processing conditions, the HDT of PLLA/talc specimens reached a similar value at a talc content of 20 wt.%, which was much higher than the BAAD content. Differential scanning calorimetry and X-ray diffraction analyses were applied to determine the melting and crystallization behavior of the PLLA/BAAD blends. Polarized optical microscopy was used to observe the crystalline morphologies. Thermogravimetric analysis was employed to study the effect of BAAD on the thermal stability of PLLA. Measurement of the mechanical property confirmed that the addition of BAAD was beneficial to the enhancement of the mechanical properties of the resulting blends. However, the tensile strength of the PLLA/talc composites decreased with increasing weight fraction of talc.

scholarly journals Partial Threading of Pedicle Screws in a Standard Construct Increases Fatigue Life: A Biomechanical Analysis

2021 ◽  
Vol 11 (4) ◽  
pp. 1503
Author(s):  
Fon-Yih Tsuang ◽  
Chia-Hsien Chen ◽  
Lien-Chen Wu ◽  
Yi-Jie Kuo ◽  
Yueh-Ying Hsieh ◽  
...  
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Shaft Length ◽  
Element Analysis ◽  
Screw Design ◽  
Screw Length

This study proposed a pedicle screw design where the proximal 1/3 of the screw is unthreaded to improve fixation in posterior spinal surgery. This design was also expected to reduce the incidence of mechanical failure often observed when an unsupported screw length is exposed outside the vertebra in deformed or degenerated segments. The aim of this study was to evaluate the fatigue life of the novel pedicle screw design using finite element analysis and mechanical testing in a synthetic spinal construct in accordance with American Society for Testing and Materials (ASTM) F1717. The following setups were evaluated: (i) pedicle screw fully inserted into the test block (EXP-FT-01 and EXP-PU-01; full thread (FT), proximal unthread (PU)) and (ii) pedicle screw inserted but leaving an exposed shaft length of 7.6 mm (EXP-FT-02 and EXP-PU-02). Corresponding finite element models FEM-FT-01, FEM-FT-02, FEM-PU-01, and FEM-PU-02 were also constructed and subjected to the same loading conditions as the experimental groups. The results showed that under a 220 N axial load, the EXP-PU-01 group survived the full 5 million cycles, the EXP-PU-02 group failed at 4.4 million cycles on average, and both EXP-FT-01 and EXP-FT-02 groups failed after less than 1.0 million cycles on average, while the fatigue strength of the EXP-FT-02 group was the lowest at 170 N. The EXP-FT-01 and EXP-FT-02 constructs failed through fracture of the pedicle screw, but a rod fractured in the EXP-PU-02 group. In comparison to the FEM-FT-01 model, the maximum von Mises stress on the pedicle screw in the FEM-PU-01 and FEM-PU-02 models decreased by −43% and −27%, respectively. In conclusion, this study showed that having the proximal 1/3 of the pedicle screw unthreaded can reduce the risk of screw fatigue failure when used in deformed or degenerated segments.

scholarly journals Biomechanical analysis of subcondylar fracture fixation using miniplates at different positions and of different lengths

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chao-Min Huang ◽  
Man-Yee Chan ◽  
Jui-Ting Hsu ◽  
Kuo-Chih Su
Keyword(s):  
Fracture Fixation ◽  
Reaction Force ◽  
Fracture Site ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Posterior Portion ◽  
Subcondylar Fracture ◽  
Sliding Distance ◽  
Subcondylar Region

Abstract Background Many types of titanium plates were used to treat subcondylar fracture clinically. However, the efficacy of fixation in different implant positions and lengths of the bone plate has not been thoroughly investigated. Therefore, the primary purpose of this study was to use finite element analysis (FEA) to analyze the biomechanical effects of subcondylar fracture fixation with miniplates at different positions and lengths so that clinicians were able to find a better strategy of fixation to improve the efficacy and outcome of treatment. Methods The CAD software was used to combine the mandible, miniplate, and screw to create seven different FEA computer models. These models with subcondylar fracture were fixed with miniplates at different positions and of different lengths. The right unilateral molar clench occlusal mode was applied. The observational indicators were the reaction force at the temporomandibular joint, von Mises stress of the mandibular bone, miniplate and screw, and the sliding distance on the oblique surface of the fracture site at the mandibular condyle. Results The results showed the efficacy of fixation was better when two miniplates were used comparing to only one miniplates. Moreover, using longer miniplates for fixation had better results than the short one. Furthermore, fixing miniplates at the posterior portion of subcondylar region would have a better fixation efficacy and less sliding distance (5.46–5.76 μm) than fixing at the anterolateral surface of subcondylar region (6.10–7.00 μm). Conclusion Miniplate fixation, which was placed closer to the posterior margin, could effectively reduce the amount of sliding distance in the fracture site, thereby achieving greater stability. Furthermore, fixation efficiency was improved when an additional miniplate was placed at the anterior margin. Our study suggested that the placement of miniplates at the posterior surface and the additional plate could effectively improve stability.

scholarly journals Biomechanical Analysis of the Forces Exerted during Different Occlusion Conditions following Bilateral Sagittal Split Osteotomy Treatment for Mandibular Deficiency

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yuan-Han Chang ◽  
Man-Yee Chan ◽  
Jui-Ting Hsu ◽  
Han-Yu Hsiao ◽  
Kuo-Chih Su
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Stress ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Intermaxillary Fixation ◽  
Element Analysis ◽  
Sagittal Split Osteotomy ◽  
Bilateral Sagittal Split Osteotomy ◽  
External Forces

The bilateral sagittal split osteotomy (BSSO) technique is commonly used to correct mandibular deficiency. If the patient is exposed to excessive external forces after the procedure, occlusal changes or nonunion may occur. However, previous studies only focused on single external forces on the mandible and did not conduct relevant research on the forces exerted by different occlusion conditions. The main purpose of this study was to use finite element analysis methods to determine the biomechanics of four common occlusion conditions after BSSO surgical treatment. This study constructed a finite element analysis computer model of a miniplate implanted in the lower jaw. The structure of the model consisted of the mandible, miniplate, and screws. In addition, external forces were applied to the superficial masseter, deep masseter, medial pterygoid, anterior temporalis, middle temporalis, and posterior temporalis muscles to simulate the incisal clench, intercuspal position (ICP), right unilateral molar clench (RMOL), and right group function occlusion conditions. Subsequently, this study observed the effects of these conditions on the miniplate, screws, and mandible, including the von Mises stress values. The results showed that all of the different occlusion conditions that this study evaluated placed high stress on the miniplate. In the ICP and RMOL occlusion conditions, the overall mandibular structure experienced very high stress. The screw on the proximal segment near the bone gap experienced high stress, as did the screw on the buccal side. According to the present analysis, although the data were not directly obtained from clinical practice, the finite element analysis could evaluate the trend of results under different external forces. The result of this study recommended that patients without intermaxillary fixation avoid the ICP and RMOL occlusion conditions. It can be used as a pilot study in the future for providing clinicians more information on the biomechanics of implantation.

scholarly journals The Analysis of Stone Trapping in Tire Tread for Various Road Conditions

2021 ◽  
Vol 335 ◽  
pp. 03003
Author(s):  
Jun Yi Eugene Gow ◽  
Pei Xuan Ku
Keyword(s):  
Elastic Strain ◽  
Von Mises Stress ◽  
Analysis Method ◽  
Total Deformation ◽  
Element Analysis ◽  
Wear And Tear ◽  
Steady State Rolling ◽  
Von Mises ◽  
Trapping Performance ◽  
Tire Models

A tire tends to trap stones in its tread pattern when the vehicle is on a move and this might affects the tire balance due to uneven tread wear of tread portion. The study aims to simulate stone trapping performance under various tire tread patterns and road conditions as well as assessing the performance of tires with stones trapped. The stone trapping phenomena on different tire tread pattern were analyzed under dry and wet road conditions. The tire models chosen were the symmetrical tire, asymmetrical tire, and directional tire. The model of these tires, stone and a flat road surface were created using SolidWorks and Fusion360 software and the static structural simulation is performed by using finite element analysis method. Tire inflation analysis and steady state rolling analysis were conducted to evaluate three parameters: total deformation, Von-Mises stress and equivalent elastic strain of the tires. It found that all three parameters are higher when stone trapped in tire for all tread pattern types. Symmetrical tread pattern provides the least wear and tear since it has the lowest increment of maximum equivalent elastic strain in both road conditions. Stone trapping in tire grooves would impact on the lifespan of the tire.

scholarly journals Thermal properties of epoxy nanoclay composite materials

2021 ◽  
Vol 2070 (1) ◽  
pp. 012171
Author(s):  
Dandapani ◽  
K Devendra ◽  
Revennasiddappa ◽  
S Girish
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Composite Material ◽  
Thermal Properties ◽  
Composite Materials ◽  
Weight Fraction ◽  
Insulating Materials ◽  
Pure Epoxy ◽  
Eds Analysis ◽  
Prepared Composite

Abstract Composite materials are an emerging topic for research as a new competitive material in engineering. New classes of composite material manufactured from particles, nanoparticles and resins, and have experienced efficient and economical for the development and also replacement of new as well as deteriorating structures. In this study epoxy-nanoclay composite materials with varying compositions of nanoclay compared with pure epoxy and epoxy with 10, 20, and 30 by weight fraction of nanoclay are prepared for better insulating materials. The various thermal properties of the material were analyzed to demonstrate that the the prepared composite is a good insulator. An increase in specific heat maximum by 11.26%, thermal stability by 58.82% results in decrease in thermal conductivity maximum by 25.65%, diffusivity to 46.8% and also co-efficient of thermal expansion with an increase in nanoclay proportion is observed. DSC, TGA and TMA are used for determining the thermal properties. SEM and EDS analysis were used to show homogeneous mixture of epoxy and nanoclay.

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