Study and Application of PBA Tunneling Technology in Shenyang Metro

2013 ◽  
Vol 353-356 ◽  
pp. 1386-1389
Author(s):  
Zhan Guo Zhu ◽  
Wen Zhao ◽  
Xiao Bing Tan ◽  
Xin Xie
Keyword(s):  
Ground Surface ◽  
Internal Force ◽  
Surface Subsidence ◽  
Construction Process ◽  
Analysis Method ◽  
Element Analysis ◽  
Construction Procedure ◽  
The Finite Element Analysis ◽  
Ground Surface Subsidence ◽  
Construction Parameter

The construction procedure of subsurface excavation method is very complex. In order to obtain the regular pattern that the construction process of pile hole may influence the ground surface subsidence, the author use Lizheng software to analysis the construction parameter of excavation, installation and removal of the support, back building etc. Using the finite element analysis method, the author simulate the surface subsidence. Comparing the simulation results with the measured data, the author get the regular patter of surface subsidence and the envelope diagram of Internal force and displacement of the retaining pile.

Use of the Finite Element Analysis Method in Pedodontics

2018 ◽  
Vol 55 (4) ◽  
pp. 666-675
Author(s):  
Mihaela Tanase ◽  
Dan Florin Nitoi ◽  
Marina Melescanu Imre ◽  
Dorin Ionescu ◽  
Laura Raducu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Model ◽  
Analysis Method ◽  
Ansys Software ◽  
Concentrated Force ◽  
Element Analysis ◽  
Finite Element Analysis Method ◽  
The Finite Element Analysis ◽  
Solid Type

The purpose of this study was to determinate , using the Finite Element Analysis Method, the mechanical stress in a solid body , temporary molar restored with the self-curing GC material. The originality of our study consisted in using an accurate structural model and applying a concentrated force and a uniformly distributed pressure. Molar structure was meshed in a Solid Type 45 and the output data were obtained using the ANSYS software. The practical predictions can be made about the behavior of different restorations materials.

Finite Element Analysis on Rack and Pinion of Roadheader

2013 ◽  
Vol 791-793 ◽  
pp. 718-721
Author(s):  
Man Man Xu ◽  
Yu Li ◽  
Sai Nan Xie ◽  
Qing Hua Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Spur Gear ◽  
Stress And Strain ◽  
Analysis Method ◽  
Element Analysis ◽  
The Road ◽  
The Finite Element Analysis ◽  
Gear Rack ◽  
Stress And Strain Distribution

To analyse the road-header rack and pinion by using the finite element analysis software COSMOS/WORKS. Compared to the traditional analytic calculation and numerical analysis method, it is more intuitively get 28 ° pressure angle spur gear rack meshing stress and strain distribution, which can rack and pinion improvements designed to provide scientific reference.

scholarly journals Evaluation of the Effects of the Chincup Appliance on the Craniofacial Structures by the Finite Element Analysis

2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Fe Model ◽  
Analysis Method ◽  
Class Iii ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Clinical Changes

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.

A Non-Cyclic Method for Plastic Shakedown Analysis

2003 ◽  
Author(s):  
W. Reinhardt
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Computing Time ◽  
Strain Accumulation ◽  
Analysis Method ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Cyclic Phenomenon ◽  
Elastic Shakedown ◽  
Plastic Shakedown

Shakedown is a cyclic phenomenon, and for its analysis it seems natural to employ a cyclic analysis method. Two problems are associated when this direct approach is used in finite element analysis. Firstly, the analysis typically needs to be stabilized over several cycles, and the analysis of each individual cycle may need a considerable amount of computing time. Secondly, even in cases where a stable cycle is known to exist, the finite element analysis can show a small continuing amount of strain accumulation. For elastic shakedown, non-cyclic analysis methods that use Melan’s theorem have been proposed. The present paper extends non-cyclic lower bound methods to the analysis of plastic shakedown. The proposed method is demonstrated with several example problems.

Evaluation of Stiffness and Stress of External Fixators with Curved Acrylic Connecting Bars

2000 ◽  
Vol 13 (02) ◽  
pp. 65-72 ◽  
Author(s):  
R. Shahar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stainless Steel ◽  
Axial Compression ◽  
External Fixator ◽  
External Fixators ◽  
Analysis Method ◽  
Lateral Bending ◽  
Element Analysis ◽  
The Finite Element Analysis

SummaryThe use of acrylic connecting bars in external fixators has become widespread in veterinary orthopaedics. One of the main advantages of an acrylic connecting bar is the ability to contour it into a curved shape. This allows the surgeon to place the transcortical pins according to safety and convenience considerations, without being bound by the requirement of the standard stainless steel connecting bar, that all transcortical pins be in the same plane.The purpose of this study was to evaluate the stiffness of unilateral and bilateral medium-sized external fixator frames with different curvatures of acrylic connecting bars. Finite element analysis was used to model the various frames and obtain their stiffness under four types of load: Axial compression, four-point medio-lateral bending, fourpoint antero-posterior bending and torsion. The analysis also provided the maximal pin stresses occurring in each frame for each loading condition.Based on the results of this study, curvatures of acrylic connecting bars of up to a maximal angular difference between pins of 25° will result in very similar stiffness and maximal pin stresses to those of the equivalent, uniplanar stainless steel system. In both unilateral and bilateral systems the stiffness decreases slightly as angulation increases for axial compression and medio-lateral bending, increases slightly for torsion and increases substantially for antero-posterior bending.External fixator systems with curved acrylic connecting bars are commonly used in veterinary orthopaedics. This paper evaluates the biomechanical performance of such systems by applying the finite element analysis method. It shows that external fixators with curved acrylic connecting bars exhibit stiffness and maximal pin stresses which are similar to those of the standard stainless steel system.

Simulation and validation of long-term ground surface subsidence in continuous permafrost, western Arctic Canada

2020 ◽  
Author(s):  
H. Brendan O'Neill ◽  
Yu Zhang
Keyword(s):  
Ground Surface ◽  
Surface Subsidence ◽  
Active Layer Thickness ◽  
Mackenzie Delta ◽  
Air Temperatures ◽  
Nest Model ◽  
Elevation Changes ◽  
Ice Content ◽  
Ground Surface Subsidence

<p>Ground surface subsidence caused by the melt of excess ice is a key geomorphic process in permafrost regions. Subsidence can damage infrastructure, alter ecology and hydrology, and influence carbon cycling. The Geological Survey of Canada maintains a network of thaw tubes in northwestern Canada, which records annual thaw penetration, active-layer thickness, and ground surface elevation changes at numerous sites. Measurements from the early 1990s from 17 sites in the Mackenzie Delta area have highlighted persistent increases in thaw penetration in response to rising air temperatures. These increases in thaw penetration have been accompanied by significant ground surface subsidence (~5 to 20 cm) at 10 ice rich sites, with a median subsidence rate of 0.4 cm a<sup>-1</sup> (min: 0.2, max: 0.8 cm a<sup>-1</sup>). Here we present preliminary results comparing these long-term field data to simulations for two observation sites using the Northern Ecosystem Soil Temperature (NEST) model. NEST has been modified to include a routine that accounts for ground surface subsidence caused by the melt of excess ground ice. The excess ice content of upper permafrost in the simulations was estimated based on ratios between thaw penetration and subsidence measured at each thaw tube. The NEST simulations begin in 1901, and there is little ground surface subsidence until the 1980s. The simulated rate of ground surface subsidence increases in the 1990s. The modelled ground surface subsidence is in good agreement with the measured annual magnitudes and longer-term patterns over the measurement period from 1992 to 2017. This preliminary assessment indicates that the modified NEST model is capable of predicting gradual thaw subsidence in ice-rich permafrost environments over decadal timescales.</p>

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