scholarly journals The morphological mapping of lateral compression type 1 pelvic fracture and pelvic ring stability classification: a finite element analysis

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Bin-Fei Zhang ◽  
Jun Wang ◽  
Yu-Min Zhang ◽  
Hui-Guang Cheng ◽  
Qian-Yue Cheng ◽  
...  
Keyword(s):  
Machine Learning ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Pelvic Ring ◽  
Von Mises Stress ◽  
Lateral Compression ◽  
Element Analysis ◽  
Pubic Ramus ◽  
Maximum Deformation ◽  
Ring Stability

Abstract Purpose This finite element analysis assessed lateral compression (LC-1) fracture stability using machine learning for morphological mapping and classification of pelvic ring stability. Methods Computed tomography (CT) files of LC-1 pelvic fractures were collected. After morphological mapping and producing matrix data, we used K-means clustering in unsupervised machine learning to classify the fractures. Based on these subtypes, we manually added fracture lines in ANSYS software. Finally, we performed a finite element analysis of a normal pelvis and eight fracture subtypes based on von Mises stress and total deformation changes. Results A total of 218 consecutive cases were analyzed. According to the three main factors—zone of sacral injury and completion, pubic ramus injury side, and the sagittal rotation of the injured hemipelvis—the LC-1 injuries were classified into eight subtypes (I–VIII). No significant differences in stress or deformation were observed between unilateral and bilateral public ramus fractures. Subtypes VI and VIII showed the maximum stress while subtypes V–VIII showed the maximum deformation in the total pelvis and sacrum. The subtypes did not differ in superior public ramus deformation. Conclusions Complete fracture of sacrum zones 2/3 may be a feature of unstable LC-1 fractures. Surgeons should give surgical strategies for subtypes V–VIII.

scholarly journals Finite Element Analysis of Different Percutaneous Fixation Strategies Used for the Treatment of Tile C1.2 Pelvic Fracture

2020 ◽  
Author(s):  
changqing Xu ◽  
wanbo Zhu ◽  
lei Liu ◽  
jiazhao Yang ◽  
shiyuan Fang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pelvic Fracture ◽  
Pelvic Ring ◽  
Strong Stability ◽  
Von Mises Stress ◽  
Percutaneous Fixation ◽  
Element Analysis ◽  
Sacroiliac Screw ◽  
Software Models

Abstract Objectives We evaluated the biomechanical outcomes of 9 different percutaneous fixation strategies used for the fixation of Tile C1.2 pelvic fracture. This may help surgeons choose the optimal therapy for the unstable pelvic fracture. Methods Tile C1.2 pelvic fractures and implant models were constructed using finite element analysis (FEA) software. Models were assembled for different fracture fixation types. After meshing the models’ elements, we used Abaqus software to perform the FEA. Values of the von Mises Stress and model displacement were used to capture the mechanical factors. Results The FEA shows that under axial loading and external rotational loading of 500 N, the combination of an S1 screw and the Infix system provide strong stability, and that an increased number of screws to fix the anterior pelvic ring increased stability. Conclusion This study indicates that a 3-screw-Infix system on the healthy side, plus an S1 sacroiliac screw improves stability of the Tile C1.2 fracture.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Bionic design of the tower for wind turbine

2021 ◽  
pp. 095440622110046
Author(s):  
Yuqiao Zheng ◽  
Fugang Dong ◽  
Huquan Guo ◽  
Bingxi Lu ◽  
Zhengwen He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Maximum Stress ◽  
Natural Frequencies ◽  
Bionic Design ◽  
Analytic Hierarchy ◽  
Element Analysis ◽  
Maximum Deformation ◽  
Overall Stability ◽  
Biological Selection

The study obtains a methodology for the bionic design of the tower for wind turbines. To verify the rationality of the biological selection, the Analytic Hierarchy Procedure (AHP) is applied to calculate the similarity between the bamboo and the tower. Creatively, a bionic bamboo tower (BBT) is presented, which is equipped with four reinforcement ribs and five flanges. Further, finite element analysis is employed to comparatively investigate the performance of the BBT and the original tower (OT) in the static and dynamic. Through the investigation, it is suggested that the maximum deformation and maximum stress can be reduced by 5.93 and 13.75% of the BBT. Moreover, this approach results in 3% and 1.1% increase respectively in the First two natural frequencies and overall stability.

scholarly journals A Machine Learning Approach as a Surrogate for a Finite Element Analysis: Status of Research and Application to One Dimensional Systems

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1654
Author(s):  
Poojitha Vurtur Badarinath ◽  
Maria Chierichetti ◽  
Fatemeh Davoudi Kakhki
Keyword(s):  
Machine Learning ◽  
Neural Networks ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Artificial Neural Networks ◽  
Stress Distribution ◽  
Maintenance Scheduling ◽  
Element Analysis ◽  
One Dimensional ◽  
Artificial Neural

Current maintenance intervals of mechanical systems are scheduled a priori based on the life of the system, resulting in expensive maintenance scheduling, and often undermining the safety of passengers. Going forward, the actual usage of a vehicle will be used to predict stresses in its structure, and therefore, to define a specific maintenance scheduling. Machine learning (ML) algorithms can be used to map a reduced set of data coming from real-time measurements of a structure into a detailed/high-fidelity finite element analysis (FEA) model of the same system. As a result, the FEA-based ML approach will directly estimate the stress distribution over the entire system during operations, thus improving the ability to define ad-hoc, safe, and efficient maintenance procedures. The paper initially presents a review of the current state-of-the-art of ML methods applied to finite elements. A surrogate finite element approach based on ML algorithms is also proposed to estimate the time-varying response of a one-dimensional beam. Several ML regression models, such as decision trees and artificial neural networks, have been developed, and their performance is compared for direct estimation of the stress distribution over a beam structure. The surrogate finite element models based on ML algorithms are able to estimate the response of the beam accurately, with artificial neural networks providing more accurate results.

scholarly journals 3D Finite Element Analysis of Rotary Instruments in Root Canal Dentine with Different Elastic Moduli

2021 ◽  
Vol 11 (6) ◽  
pp. 2547 ◽  
Author(s):  
Carlo Prati ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alexandre Luiz Souto Borges ◽  
Maurizio Ventre ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Root Canal ◽  
Elastic Moduli ◽  
Reaction Force ◽  
Von Mises Stress ◽  
Elastic Behavior ◽  
Element Analysis ◽  
Heat Treated ◽  
Von Mises

The aim of the present investigation was to calculate the stress distribution generated in the root dentine canal during mechanical rotation of five different NiTi endodontic instruments by means of a finite element analysis (FEA). Two conventional alloy NiTi instruments F360 25/04 and F6 Skytaper 25/06, in comparison to three heat treated alloys NiTI Hyflex CM 25/04, Protaper Next 25/06 and One Curve 25/06 were considered and analyzed. The instruments’ flexibility (reaction force) and geometrical features (cross section, conicity) were previously investigated. For each instrument, dentine root canals with two different elastic moduli(18 and 42 GPa) were simulated with defined apical ratios. Ten different CAD instrument models were created and their mechanical behaviors were analyzed by a 3D-FEA. Static structural analyses were performed with a non-failure condition, since a linear elastic behavior was assumed for all components. All the instruments generated a stress area concentration in correspondence to the root canal curvature at approx. 7 mm from the apex. The maximum values were found when instruments were analyzed in the highest elastic modulus dentine canal. Strain and von Mises stress patterns showed a higher concentration in the first part of curved radius of all the instruments. Conventional Ni-Ti endodontic instruments demonstrated higher stress magnitudes, regardless of the conicity of 4% and 6%, and they showed the highest von Mises stress values in sound, as well as in mineralized dentine canals. Heat-treated endodontic instruments with higher flexibility values showed a reduced stress concentration map. Hyflex CM 25/04 displayed the lowest von Mises stress values of, respectively, 35.73 and 44.30 GPa for sound and mineralized dentine. The mechanical behavior of all rotary endodontic instruments was influenced by the different elastic moduli and by the dentine canal rigidity.

Investigating the Calibration Curves for a Two Component Cutting Tool Lathe Dynamometer Using Finite Element Analysis

2016 ◽  
Vol 24 ◽  
pp. 71-84
Author(s):  
Osezua Obehi Ibhadode ◽  
Ishaya Musa Dagwa ◽  
Akii Okonigbon Akhaehomen Ibhadode
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cutting Tool ◽  
Von Mises Stress ◽  
Equation Modeling ◽  
Element Analysis ◽  
Calibration Curves ◽  
Two Component ◽  
Applied Forces ◽  
Von Mises

Calibration curves of a multi-component dynamometer is of essence in machining operations in a lathe machine as they serve to provide values of force and stress components for cutting tool development and optimization. In this study, finite element analysis has been used to obtain the deflection and stress response of a two component cutting tool lathe dynamometer, for turning operation, when the cutting tool is subjected to cutting and thrust forces from 98.1N to 686.7N (10 to 70kg-wts), at intervals of 98.1N(10kg-wt). By obtaining the governing equation, modeling the dynamometer assembly, defining boundary conditions, generating the assembly mesh, and simulating in Inventor Professional; horizontal and vertical components of deflection by the dynamometer were read off for three different loading scenarios. For these three loading scenarios, calibration plots by experiment compared with plots obtained from simulation by finite element analysis gave accuracies of 79%, 95%, 84% and 36%, 57%, 63% for vertical and horizontal deflections respectively. Also, plots of horizontal and vertical components of Von Mises stress against applied forces were obtained.

scholarly journals Simulasi Kekuatan Mekanik Sudu Turbin Angin Horizontal Menggunakan Software Simscale

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Mubni Nazar ◽  
Anggito Pringgo Tetuko ◽  
Djuhana Djuhana
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Von Mises

Penelitian ini dilakukan untuk meningkatkan koefisien daya yang maksimal. Salah satunya dengan mengunakan kualitas sudu yang baik. Untuk mengoptimalkan fungsi turbin angin penulis menggunakan material sudu pada turbin angin dengan menggunakan Acrylonitrine Butadine Styrene (ABS). Oleh karena itu pada penelitian ini metode yang digunakan adalah metode Finite Element Analysis Simulasi yang dipilih adalah dynamic. Penelitian ini adalah pengujian kekuatan sudu turbin angin horizontal dengan variasi kecepatan angin 10 – 20 m/s ditinjau dari von mises stress dan displacement. Dari hasil simulasi kecepatan angin memiiki pengaruh terhadap distribusi stress dan displacement. Material yang digunakan masih berada di bawah batas kekuatan material, semakin besar gaya yang diberikan semakin besar nilai stress dan displacement. Pada hasil simulasi didapatkan nilai stress minimum 5.8 Pa stress maksimum 22.94 Sedangkan dalam pengujian displacement dihasilkan nilai minimum 1.27 m displacement maksimum 4.99 m.

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