scholarly journals Three dimensional modelling of interaction between surface and Darcy flow regimes through soils

2009 ◽  
Vol 60 (7) ◽  
pp. 1911-1918 ◽  
Author(s):  
B. Kaveh-Baghbaderani ◽  
V. Nassehi ◽  
A. Kulkarni
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Surface Flow ◽  
Hydrodynamic Conditions ◽  
Dimensional Finite Element ◽  
Finite Element Procedure ◽  
Darcy Equations ◽  
Underground Flow ◽  
Three Dimensional Finite Element ◽  
The Impact

The present paper deals with the impact of surface flow on hydrodynamic conditions in saturated underground domains. A three dimensional finite element scheme has been used to simulate underground flow resulting from the flow of water over a saturated land. The results clearly show the effects of the surface flow on the hydrodynamic conditions of the subsurface porous regions. This analysis is an important prerequisite for the prediction of contaminant mobility in soils and hence provides a convenient tool for the prediction of interaction between surface and subsurface flow processes. For low permeability cases, considered here, the governing equations consist of water continuity and Darcy equations. These equations are solved using a robust and reliable finite element procedure.

Optimization of the Engine Hood to Reduce the Head Injury during the Vehicle-Human Collision

2012 ◽  
Vol 192 ◽  
pp. 29-36
Author(s):  
Yu Xin Wang ◽  
Qing Chun Wang ◽  
Jian Rong Fu ◽  
Hong Hai Qiao
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Optimization Design ◽  
Three Dimensional ◽  
Element Model ◽  
Head Model ◽  
Modeling Software ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Impact

Effect of hard point of the engine hood on the head injury during the vehicle-human collision was studied to improve the design of engine hood. Firstly, the current common model of the engine hood was established with three-dimensional finite element modeling software, and 20 areas were divided, also a standard head finite element model was imported, secondly, each area of the engine hood was clashed by the standard head model, then the impact on the head injure was analyzed and the hard point of the hood area was achieved, thirdly, the optimization of the inside and outside panel materials and the plate structure were carried out to reduce the head damage. The simulation results show that the engine hood after optimization gave less damage to the head, which means the research carried out here is of a good reference to the engine hood optimization design for human protection

Simulation and Test for the Lightning Damage of the Glass Fiber Composites

2014 ◽  
Vol 1003 ◽  
pp. 78-84
Author(s):  
Xiao Ning Chen ◽  
Jin Long Zhao ◽  
Yun Sheng Zhang ◽  
Bin Zhang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Damage Mechanism ◽  
Glass Fiber Composites ◽  
Dimensional Finite Element ◽  
Aircraft Composites ◽  
Three Dimensional Finite Element ◽  
The Impact ◽  
Composites Panel

Theoretical deducing, simulated lightning test and finite element simulation are used to research the mechanism and state of lightning damage of the aircraft composites sandwich panels. It provides the basis for the design of the aircraft lightning protection. The three-dimensional finite element model of the composites panel is constructed through the thermal electrical-mechanical multi-Physics coupling field. According to the structure and the role process, the lightning effect of the aircraft composites is analysed to study the damage mechanism and the possible state of the composites panel that is struck by lightning. The impact current generator is used to carry out the simulated lightning test to observe the lightning effect of the composites panel. By comparing the results of the test and the simulation, the effectiveness and the correctness of the simulation are verified.

scholarly journals ANALYSIS OF THE COMBINATION OF METHODS OF FASTENING THE JUNCTION POINT OF A HORIZONTAL TUNNEL WITH A VERTICAL SHAFT IN CONDITIONS OF DENSE URBAN DEVELOPMENT

2021 ◽  
pp. 108-115
Author(s):  
S. M. STOVPNYK ◽  
H. K. TUHANOV
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Urban Development ◽  
Three Dimensional ◽  
Digital Modeling ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Impact ◽  
Element Method

Purpose. The problem of compares the long-term behavior of a tunnel-well taking into account the rigid and flexible couplings in the projected structures in Ukraine with 3d digital modeling using the three-dimensional finite element method. A refined geotechnical model has also been developed, taking into account the nature of the piezometric starting conditions and the proposed piezometric conditions for assessing the long-term condition as well as a summary of the properties and dimensions of the tunnel and the shaft. Methodology. Analysis of structural connections based on the experience of building shallow subways in dense urban development on the example of construction projects in China and Mexico. Search for the optimal combination of implemented methods to achieve the optimal result. Problems of a choice of a mode with 3d digital modeling using the three-dimensional finite element method based on two assumptions; the first assumption considers the rigid connection as a monolithic concrete structure between the shaft wall and the tunnel body, and the second assumption considers a material with elastic behavior between the two structures, which in turn leads to a flexible connection. The main parameters that must be clarified and corrected by the designer of the system during commissioning are determined. Next, the soft soil model was used to perform the analyzes with end elements for compressible layers. Findings. Simulation in the application, the Plaxis software environment obtained graphs of transients for the most important operating parameters, such as the geometry of the tunnel and the indicated lining, the flotation pool, three-dimensional clusters. Originality. Scientific interest in advancing technologies used in combination. Development of an algorithm for the optimal selection of the parameters of flexibility and durability in specific conditions, to save time and simplify the calculation forms. Practical value. The analysis of the obtained results is carried out, the main focus was on the relative loads and stress concentrations in the connecting elements, namely the stresses that occur in the transverse direction of the joint. Also in articles were determined some of the advantages and disadvantages of the different connection alternatives are discussed in order to neutralize the impact of the case in the future.

Evaluation of Burst Pressure of Corroded Pipe Segments Using Three-Dimensional Finite Element Analyses

2018 ◽  
Author(s):  
Ji Bao ◽  
Shulong Zhang ◽  
Wenxing Zhou ◽  
Shenwei Zhang
Keyword(s):  
Finite Element ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Full Scale ◽  
Burst Pressure ◽  
Dimensional Finite Element ◽  
Tresca Criterion ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
The Impact

In this paper, three-dimensional finite element models are developed to simulate full-scale burst tests of corroded pipes containing multiple naturally occurring corrosion anomalies. Both the von Mises and Tresca yield criteria and associated flow rules are employed in finite element analysis (FEA). For the Tresca criterion, the corresponding constitutive model subroutine is developed and incorporated in the FEA. The accuracy of FEA is investigated by comparing the burst pressures observed in the tests and corresponding burst pressures predicted using FEA. The implications of using the von Mises and Tresca criteria for the accuracy of the predicted burst pressure are investigated. Sensitivity analyses are also carried out to investigate the impact on the predicted burst pressure due to the mesh density in the corroded region, characterization of the geometry of the corrosion cluster and different types of element (e.g. solid and shell elements) used in FEA. The results suggest that the Tresca criterion always underestimates the burst pressure and the von Mises yield criterion predicts the burst pressure accurately. This study demonstrates the feasibility of using high-fidelity FEA and the Tresca yield criterion to simulate full-scale burst tests of corroded pipes and therefore establish a large database of burst pressure capacities of corroded pipes that can be used to develop an accurate, practical burst pressure capacity model amenable to the pipeline integrity management practice.

Dynamic Response of the Human Head to Impact by Three-Dimensional Finite Element Analysis

1994 ◽  
Vol 116 (1) ◽  
pp. 44-50 ◽  
Author(s):  
J. S. Ruan ◽  
T. Khalil ◽  
A. I. King
Keyword(s):  
Finite Element ◽  
Fluid Layer ◽  
Three Dimensional ◽  
Human Head ◽  
Frontal Impact ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Impact ◽  
The Brain

The impact response of the human head has been determined by three-dimensional finite element modeling. This model represents the essential features of a 50th percentile human head. It includes a layered shell closely representing the cranial bones with the interior contents occupied by an inviscid continuum to simulate the brain. A thin fluid layer was included to represent the cerebral-spinal fluid. To validate the model, its response was obtained by applying a sine-squared pulse of 6.8 kN in magnitude and 10 ms in duration. The load was applied to a freely supported head on the frontal bone in the midsagittal plane. The computed pressure-time histories at 5 locations within the brain material compared quite favorably with previously published experimental data from cadaver experiments and provided a reasonable level of confidence in the validation of the model. A parametric study was subsequently conducted to identify the model response when the impact site (frontal, side, occipital) and the material properties of the head were varied. Interestingly, the model predicted higher contre-coup pressure in the frontal lobe (from occipital impact) than that predicted in the occipital region from frontal impact. This finding supports clinical findings of contre-coup injury being more likely to result from occipital impact than from frontal impact.

Parameters Setting Impact Analysis of Composite Cockpit Finite Element Analysis Based on Properties of Composite Materials

2013 ◽  
Vol 738 ◽  
pp. 103-106
Author(s):  
Hai Peng Gao ◽  
Meng Liu ◽  
Jun Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Impact Analysis ◽  
Three Dimensional ◽  
Single Layer ◽  
Uncertain Parameters ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Impact

At present, mechanics properties of composite at home and abroad only include data of the single-layer board. On the basis of researching literature of composite finite element analysis, approaches of setting composite three-dimensional parameters based on the parameters of single-layer material are summarized. By three-dimensional finite element analysis on composite whole cockpit, the impact of uncertain parameters on cockpit analysis results is studied. Adopting maximum stress criteria, maximum strain criteria and Tsai-Wu criteria to evaluate the initial failure of composite whole cockpit, the impact of material uncertain parameters on initial breaking strength prediction of cockpit is studied. The study can provide reference for three-dimensional finite element analysis of composite whole cockpit.

scholarly journals Understanding the impact of train run-throughs on railway switches using finite element analysis

2018 ◽  
Vol 233 (4) ◽  
pp. 359-369 ◽  
Author(s):  
JY Shih ◽  
H Hemida ◽  
E Stewart ◽  
C Roberts
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Designed Experiment ◽  
Explicit Analysis ◽  
Three Dimensional Finite Element ◽  
Failure Location ◽  
The Impact

Train run-throughs on railway switches is a special issue, where a train passes through non-trailable railway switches in the wrong direction. This has the potential to cause severe damage and can lead to derailment. In order to understand the impact of train run-throughs on railway switches, a three-dimensional finite element model using explicit analysis has been developed. A detailed switch model has been developed that includes all key components: stretcher bars, supplementary drive and point operating equipment. The model was validated through a specifically designed experiment where switch run-throughs were emulated on a real switch; a good agreement was found between the experimental data and the model. The model has been used to make an assessment of the locking mechanisms. The forces in each component have been assessed and investigated, and the observations of failure location and component during run-through analysis are indicated. During a run-through, the supplementary drive rod and stretcher bar encounter a significant plastic deformation, and it is recommended that they should be redesigned in order to avoid plastic behaviour.

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