The sagittal curvature of the spine can be a leading cause of scoliosis in pediatric spine

2021 ◽  
Author(s):  
S Pasha
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Early Stage ◽  
Element Model ◽  
Sagittal Profile ◽  
Deformation Pattern ◽  
Element Simulation ◽  
Curve Deformation ◽  
Numerical Finite Element ◽  
Deformation Patterns

The etiology of the adolescent idiopathic scoliosis (AIS) remains unknown. Variations in the sagittal profile of the spine between the early stage scoliotic and non-scoliotic pediatric patients have been shown. However, no quantitative study has shown the link between the sagittal profile and 3D deformity of the spine. 126 right thoracic scoliosis with spinal and 3D reconstructions were included. A 2D finite element model was developed for each of the sagittal curve types without any deformity in the frontal or axial planes. Physiological loadings were determined from the literature and were applied in the finite element model. The 3D deformation patterns of the models were compared to the 3D spinal patterns of the AIS with the same sagittal type. A significant correlation was found between the 3D deformity of the scoliotic curves and the numerical finite element simulation of the corresponding sagittal profile as determined by pattern correlation, p<0.001. The sagittal curve deformation patterns corresponded to the spinal deformities in the patients with the same sagittal curvature. Finite element models of the spines, representing different sagittal types in 126 AIS patients showed that deformation pattern of the sagittal types changes as a function of the spine curvature and associates with the patterns of 3D spinal deformity in AIS patients with the same sagittal curves. This finding provided evidence that the sagittal curve of the spine can determine the deformity patterns in AIS.

Finite Element Simulation of Tire-Rim Interface

1989 ◽  
Vol 17 (4) ◽  
pp. 305-325 ◽  
Author(s):  
N. T. Tseng ◽  
R. G. Pelle ◽  
J. P. Chang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Contact Pressure ◽  
Element Model ◽  
Experimental Measurements ◽  
Inflation Pressure ◽  
Interference Fit ◽  
Element Simulation ◽  
Rubber Composite

Abstract A finite element model was developed to simulate the tire-rim interface. Elastomers were modeled by nonlinear incompressible elements, whereas plies were simulated by cord-rubber composite elements. Gap elements were used to simulate the opening between tire and rim at zero inflation pressure. This opening closed when the inflation pressure was increased gradually. The predicted distribution of contact pressure at the tire-rim interface agreed very well with the available experimental measurements. Several variations of the tire-rim interference fit were analyzed.

3D Finite Element Simulation for Turning of Hardened 45 Steel

2019 ◽  
Vol 13 (2) ◽  
pp. 181-188
Author(s):  
Meng Liu ◽  
Guohe Li ◽  
Xueli Zhao ◽  
Xiaole Qi ◽  
Shanshan Zhao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cutting Force ◽  
Finite Element Simulation ◽  
Orthogonal Experiment ◽  
Element Model ◽  
3D Finite Element ◽  
Element Simulation ◽  
Metal Machining ◽  
Single Factor Experiment

Background: Finite element simulation has become an important method for the mechanism research of metal machining in recent years. Objective: To study the cutting mechanism of hardened 45 steel (45HRC), and improve the processing efficiency and quality. Methods: A 3D oblique finite element model of traditional turning of hardened 45 steel based on ABAQUS was established in this paper. The feasibility of the finite element model was verified by experiment, and the influence of cutting parameters on cutting force was predicted by single factor experiment and orthogonal experiment based on simulation. Finally, the empirical formula of cutting force was fitted by MATLAB. Besides, a lot of patents on 3D finite element simulation for metal machining were studied. Results: The results show that the 3D oblique finite element model can predict three direction cutting force, the 3D chip shape, and other variables of metal machining and the prediction errors of three direction cutting force are 5%, 9.02%, and 8.56%. The results of single factor experiment and orthogonal experiment are in good agreement with similar research, which shows that the model can meet the needs for engineering application. Besides, the empirical formula and the prediction results of cutting force are helpful for the parameters optimization and tool design. Conclusion: A 3D oblique finite element model of traditional turning of hardened 45 steel is established, based on ABAQUS, and the validation is carried out by comparing with experiment.

Forming limit diagrams by including the M–K model in finite element simulation considering the effect of bending

2016 ◽  
Vol 232 (8) ◽  
pp. 625-636 ◽  
Author(s):  
Mostafa Habibi ◽  
Ramin Hashemi ◽  
Ahmad Ghazanfari ◽  
Reza Naghdabadi ◽  
Ahmad Assempour
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Metal Forming ◽  
Forming Limit Diagram ◽  
Element Model ◽  
Forming Limit ◽  
Finite Element Models ◽  
Element Simulation ◽  
Simple Tension ◽  
Out Of Plane

Forming limit diagram is often used as a criterion to predict necking initiation in sheet metal forming processes. In this study, the forming limit diagram was obtained through the inclusion of the Marciniak–Kaczynski model in the Nakazima out-of-plane test finite element model and also a flat model. The effect of bending on the forming limit diagram was investigated numerically and experimentally. Data required for this simulation were determined through a simple tension test in three directions. After comparing the results of the flat and Nakazima finite element models with the experimental results, the forming limit diagram computed by the Nakazima finite element model was more convenient with less than 10% at the lower level of the experimental forming limit diagram.

The Analysis of the Stiffness about the School Bus Based on Hyper Mesh

2014 ◽  
Vol 912-914 ◽  
pp. 806-809
Author(s):  
Ming Feng Zheng ◽  
Yue Chen ◽  
Ya Lin Yan
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Local Structure ◽  
Element Model ◽  
School Bus ◽  
Element Simulation ◽  
As Stress

Established a finite element model of the school bus based on the Hyper Mesh, take a finite element simulation about the various parts of the school bus parameters such as stress, displacement and deformation under 5 conditions. Through the analysis of the school bus to identify conditions displacement of stress more concentrated area as well as in operation, by optimizing improve the local structure of these regions,improve the stress concentration and safety.

Finite Element Simulation of Metal Structure for Container Stacker Based on Ansys

2011 ◽  
Vol 94-96 ◽  
pp. 2080-2083
Author(s):  
Zhi Jian Li ◽  
Jian Kun Zhang
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Finite Element Model ◽  
Metal Structure ◽  
Element Model ◽  
Calculation Model ◽  
Ansys Software ◽  
Element Simulation ◽  
Calculation Results ◽  
The Finite Element Model

The finite element model of metal structure of 45 tons container stacker is established and Ansys software is employed to calculate the stress of key parts. The skill of model processing of the complete machine and the boundary condition of calculation model is described. The calculation results are used to guide the design of the container stacker.

Collapse Accidents Analysis and Finite Element Simulation of Fastener-Style Steel Tubular High-Formwork-Support

2011 ◽  
Vol 94-96 ◽  
pp. 1818-1823
Author(s):  
Guang Sheng Bian ◽  
Qiang Jia ◽  
An Ying Chen ◽  
Fang Gu
Keyword(s):  
Finite Element ◽  
Stability Analysis ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Element Model ◽  
Collapse Mechanism ◽  
Analytical Results ◽  
Element Simulation ◽  
The Finite Element Model ◽  
Technical Measures

There were four collapse accidents of fastener-style steel tubular formwork support being investigated in the article. The collapse mechanism was researched. According to the collapse accidents, the finite element model was established. The whole stability analysis was done. The analytical results were the same with the conditions of accidents. The collapse mechanism was verified. According to the collapse mechanism, the security technical measures of high formwork support were put forward.

A Review on the Finite Element Modeling of the Particle Reinforced Metal Matrix Composites in Cutting Process

2020 ◽  
Vol 14 (1) ◽  
pp. 39-55
Author(s):  
Xiaole Qi ◽  
Guohe Li ◽  
Qi Zhang ◽  
Fei Sun
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Element Model ◽  
Matrix Composites ◽  
Element Simulation ◽  
Element Method

Background:: Particle Reinforced Metal Matrix Composites (PRMMCs) are widely used because of the higher specific strength, better dimensional stability, lower thermal expansion coefficient, better wear and corrosion resistance. However, the existence of reinforcing particles makes it hard to machine. The main manifestations are as follows: severe tool wear, easy generation of debris tumors in processing, and many defects on the machined surface, etc. These seriously limit its wider application. The Finite Element Method (FEM) has been widely applied in the research of PRMMCs machining according to recent patents, which can improve the efficiency and reduce the cost of research. Therefore, it is necessary to carry out a deep research for the processing technology of PRMMCs. Methods:: In this paper, the latest research progress of finite element simulation of cutting PRMMCs was summarized. The key technologies of finite element simulation, including constitutive model, geometric model, friction model between chip and tool, fracture criterion and mesh generation, are comprehensively analyzed and summarized. The application in the specific processing methods was discussed, such as turning, milling, grinding, ultrasonic vibration grinding and drilling. The existing problems and development direction of the simulation of PRMMCs cutting are also given. Besides, a lot of patents on finite element simulation for PRMMCs machining were studied. Results:: Finite element model for the actual composition determines the accuracy of finite element simulation. Through the secondary development of finite element software, a more realistic finite element model of Particle reinforced metal matrix composites can be established. Conclusion:: Finite Element Method (FEM) provides a new approach for the study of mechanism of Particle reinforced metal matrix composites machining. Quantitative analysis and prediction of micro- details in cutting can be realized.

A Truck Cab Abnormal Vibration Test and Analysis

2013 ◽  
Vol 416-417 ◽  
pp. 1803-1807
Author(s):  
Qiang Li ◽  
Yan Fang Liu ◽  
Xiang Yang Xu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Radial Force ◽  
Test Results ◽  
Element Simulation ◽  
Force Variation ◽  
Specific Speed ◽  
The Finite Element Model

This paper introduces a combination of testing and finite element simulation for the abnormal vibration of a truck cab in specific speed. Vibration characteristics of the truck is tested. The factors that caused the abnormal vibration of the truck is found. The finite element model is established and the modal analysis is performed, the correctness of the test results is verified, and a reliable finite element model for the follow-up solution is provided. The abnormal vibration was caused by the frequencies of radial force variation which almost equal to the truck natural frequency under the vehicle velocities of 50km/h. The approach described in this paper can be applied to similar vibration problem diagnosis.

Initial testing of a two-dimensional finite element model for floodplain inundation

1994 ◽  
Vol 444 (1920) ◽  
pp. 149-159 ◽  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Numerical Models ◽  
Element Model ◽  
Two Dimensional ◽  
Catchment Scale ◽  
Element Simulation ◽  
Dimensional Finite Element ◽  
Floodplain Inundation ◽  
River Reach

Current research needs for the two-dimensional finite element simulation of river flood flows are discussed. It is suggested that there is a need to test such numerical models to assess critically their ability to simulate river floodplain inundation. Initial tests are undertaken within the context of an application of a two-dimensional finite element model to a 14 km river reach in the U. K. Model behaviour is examined and shown to be stable, accurate and consistent with theoretical expectations and the need for improved data acquisition for model testing is highlighted. On the basis of these numerical experiments a number of implications for current catchment scale integrated hydrological modelling are discussed.

The Establishment of Orthogonal Cutting Finite Element Model and its Key Technologies

2009 ◽  
Vol 416 ◽  
pp. 568-571
Author(s):  
You Yi Zheng ◽  
Ai Hua Gao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Element Model ◽  
Key Technology ◽  
Element Simulation ◽  
Key Technologies ◽  
Orthogonal Metal Cutting ◽  
The Finite Element Model

Based on several assumptions, this paper established the finite element model of the heat coupling of the orthogonal metal cutting, and analyzes the key technology that involved in the Orthogonal cutting finite element simulation.

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