Slip Fascia Stiffness Effect to the Fifth Metatarsal Movement during Inversion Landing

2011 ◽  
Vol 189-193 ◽  
pp. 472-475
Author(s):  
Yao Dong Gu ◽  
Xue Jun Ren ◽  
Zhi Yong Li ◽  
Guo Qing Ruan ◽  
Li Yang

Injuries of the base of the fifth metatarsal are among the most common of all skeletal injuries of the foot. The fracture is considered by previous research to be an avulsion due to the slip fascia, however, the mechanism of the plantar slip fascia’s function still not very clear. In this study, a detailed three-dimensional (3D) finite element (FE) model was developed by reconstruction of CT images. A sensitivity study was conducted to evaluate the effect of varying stiffness of the slip fascia on the fifth metatarsal’s deformation. The results showed that the largest vertical displacement was appeared in the metatarsal’s head part, and the difference was up to 10.5%, while the Young’s modulus of the slip fascia increasing from 50MPa to 500MPa.

2019 ◽  
Vol 281 ◽  
pp. 01006 ◽  
Author(s):  
Majid M.A. Kadhim ◽  
Mohammed J Altaee ◽  
Ali Hadi Adheem ◽  
Akram R. Jawdhari

Fibre reinforced cementitious matric (FRCM) is a recent application of fibre reinforced polymer (FRP) reinforcement, developed to overcome several limitations associated with the use of organic adhesive [e.g. epoxies] in FRPs. It consists of two dimensional FRP mesh saturated with a cement mortar, which is inorganic in nature and compatible with concrete and masonry substrates. In this study, a robust three-dimensional (3D) finite element (FE) model has been developed to study the behaviour of slender reinforced concrete columns confined by FRCM jackets, and loaded concentrically and eccentrically. The model accounts for material nonlinearities in column core and cement mortar, composite failure of FRP mesh, and global buckling. The model response was validated against several laboratory tests from literature, comparing the ultimate load, load-lateral deflection and failure mode. Maximum divergence between numerical and experimental results was 12%. Following the validation, the model will be used later in a comprehensive parametric analysis to gain a profound knowledge of the strengthening system, and examine the effects of several factors expected to influence the behaviour of confined member.


2006 ◽  
Vol 1 (2) ◽  
pp. 176-179
Author(s):  
Miranda N. Shaw ◽  
Vijay K. Goel ◽  
Koichi Sairyo ◽  
Jayant Jangra ◽  
Ashok Biyani ◽  
...  

An experimentally validated three-dimensional (3D) finite element (FE) model of the ligamentous L3–S1 segment was used to study the effects of artificial facet designs on the segment biomechanics (motion, facet loads, and stresses). The intact model was modified to simulate several artificial facet designs across the L4–L5 segment including capping with and without screws and pedicle screw based designs with sliding articulating surfaces. For the pedicle screw based design, the effect of increasing the connecting shaft thickness and increasing width surrounding the pedicle screw, butted against the vertebral pedicle for further support, was studied. All of the FE models were evaluated in response to 6 Nm moment in extension, flexion, bending, and rotation. The predicted increases in motion, compared to the intact case, were smaller. The predicted facet loads decreased up to 25.7% in extension and 25.1% in bending at the implanted level as compared to intact spine segment. For all of the loading modes, the stresses in both implant designs were less than the yield stress of titanium. Therefore, the implants are unlikely to fail. Additional cadaver and other experimental protocols are essential for the evaluations of the most appropriate designs identified through the FE investigations.


2011 ◽  
Vol 189-193 ◽  
pp. 2092-2095
Author(s):  
Min Wang

For ring rolling without axial rolls, how to effectively suppress axial spread has become an important subject. In the paper, a reliable coupled thermo-mechanical three-dimensional (3D) finite element (FE) model for hot rolling of large rings is developed. Spread evolution of titanium alloy large rings with different sizes are explored and compared based the developed model. The main results show that (1) the spread in a ring takes on an axisymmetric distribution after the first revolution of the ring. (2) with the equivalent ratio of feed amount per revolution decreasing, the peak spread transfers from the outer layer to the inner layer for rings with different sizes.


Author(s):  
Qingzhen Lu ◽  
Zhixun Yang ◽  
Jun Yan ◽  
Hailong Lu ◽  
Jinlong Chen ◽  
...  

Umbilical is an important equipment in the subsea production to supply a connection between the floater and the subsea well. Analyzing strength and fatigue behaviors under bending is a key requirement to assure safety. An analytical model is proposed for predicting the bending behavior of a steel tube wounded helically around a frictionless cylinder. A full three-dimensional (3D) finite element (FE) model of an umbilical is developed by considering the frictions and contacts among its components. The numerical results of the bending stress of a steel tube were validated against that of the analytical model. The impacts of friction coefficients on the bending stress, contact pressure, and friction stress have been further investigated by the established FE model.


Vibration ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 151-174
Author(s):  
André F. S. Rodrigues ◽  
Zuzana Dimitrovová

In this paper, the three-layer model of ballasted railway track with discrete supports is analyzed to access its applicability. The model is referred as the discrete support model and abbreviated by DSM. For calibration, a 3D finite element (FE) model is created and validated by experiments. Formulas available in the literature are analyzed and new formulas for identifying parameters of the DSM are derived and validated over the range of typical track properties. These formulas are determined by fitting the results of the DSM to the 3D FE model using metaheuristic optimization. In addition, the range of applicability of the DSM is established. The new formulas are presented as a simple computational engineering tool, allowing one to calculate all the data needed for the DSM by adopting the geometrical and basic mechanical properties of the track. It is demonstrated that the currently available formulas have to be adapted to include inertial effects of the dynamically activated part of the foundation and that the contribution of the shear stiffness, being determined by ballast and foundation properties, is essential. Based on this conclusion, all similar models that neglect the shear resistance of the model and inertial properties of the foundation are unable to reproduce the deflection shape of the rail in a general way.


Author(s):  
Demeng Che ◽  
Jacob Smith ◽  
Kornel F. Ehmann

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.


Author(s):  
R. N. Margasahayam ◽  
H. S. Faust

Abstract A finite-element stress analysis of a one-piece, integrated, all-composite shaft and coupling is presented. In addition to a brief discussion of design-driving parameters, some limitations of the analytical techniques used for design development are described. The 3D finite-element method (FEM) was then used to evaluate critical stresses and strains experienced by the shaft coupling. A comparison of the results from the finite-element analysis and those from static bending, axial, and torsional tests conducted on these prototype shafts yielded excellent correlation. Some important considerations in the development of the FE model and the correlation of results with tests, especially in the design of composite materials, are addressed.


2014 ◽  
Vol 695 ◽  
pp. 588-591
Author(s):  
Khairul Salleh Basaruddin ◽  
Ruslizam Daud

This study aims to investigate the influence of trabecular bone in human mandible bone on the mechanical response under implant load. Three dimensional voxel finite element (FE) model of mandible bone was reconstructed from micro-computed tomography (CT) images that were captured from bone specimen. Two FE models were developed where the first consists of cortical bone, trabecular bone and implants, and trabecular bone part was excluded in the second model. A static analysis was conducted on both models using commercial software Voxelcon. The results suggest that trabecular bone contributed to the strength of human mandible bone and to the effectiveness of load distribution under implant load.


2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.


2014 ◽  
Vol 989-994 ◽  
pp. 982-985
Author(s):  
Jun Chen ◽  
Xiao Jun Ye

ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .


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