scholarly journals Analysis of the Embankment Settlement on Soft Soil Subgrade with a Cement Mixed Pile

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Liang Yang ◽  
Wenyuan Xu ◽  
Keke Li
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Soft Soil ◽  
Element Analysis ◽  
Pile Spacing ◽  
Pile Diameter ◽  
Elastoplastic Constitutive Model ◽  
The Impact ◽  
Pile Length ◽  
Road Slope

The settlement of the widening of soft soil subgrade highways is typically associated with different treatment positions of cement mixed piles. In order to overcome this, in the current paper we employ the finite element method to simulate and analyze the influence of piles under an existing road slope and under an existing subgrade and new embankment on the settlement characteristics of the subgrade and foundation. In particular, we focus on the influence of the pile length and pile spacing on the subgrade and foundation settlements based on a northern high-speed reconstruction and expansion project. The subgrade and foundation soils in the finite element analysis are considered to be homogeneous, continuous, and isotropic elastoplastic materials. The Mohr–Coulomb ideal elastoplastic constitutive model is implemented as the constitutive soil model. The impact of piles under an existing subgrade and new embankment on the settlement is observed to be more significant than that of piles under the existing road slope. Moreover, the subgrade and foundation settlements increase with the pile spacing under the existing road slope and under the existing subgrade and new embankment. More specifically, an increase of the pile spacing from 200% to 400% of the pile diameter is associated with an increase in the maximum settlement of the foundation surface from 1.76 to 1.85 cm (existing road slope) and from 1.44 to 1.96 cm (existing subgrade and new embankment). In addition, the subgrade and foundation settlements decrease for increasing pile lengths under the existing road slope and under the existing subgrade and new embankment, the pile length increases from 4.7 to 9.2 m, and the maximum foundation surface settlement is reduced from 6.2 to 5.52 cm and from 9.73 to 5.43 cm, respectively. The results can provide reference for future subgrade widening projects.

The Finite Element Analysis of Dynamic Interaction of High-Speed Shinkansen, the Rail, and Bridge

1993 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Response Analysis ◽  
Element Formulation ◽  
Element Analysis ◽  
Finite Element Program ◽  
The Finite Element Analysis ◽  
Element Program ◽  
The Impact

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.

Piled Raft Structure Finite Element Analysis of Composite Foundation Settlement in Da XI Passenger Dedicated Line

2014 ◽  
Vol 937 ◽  
pp. 438-443
Author(s):  
Xiao Tong Ma ◽  
Guang Long Liu
Keyword(s):  
Finite Element ◽  
Composite Foundation ◽  
Foundation Settlement ◽  
Pile Spacing ◽  
Finite Element Software ◽  
Piled Raft ◽  
Pile Diameter ◽  
Foundation Treatment ◽  
Pile Length ◽  
Passenger Dedicated Line

Composite foundation settlement of piled raft structure in Da Xi passenger dedicated line is analyzed by the large finite element software MIDAS/GTS and established calculation model of foundation treatment. The problem of pile-soil contact is highlighted in the trail and analyzes the settlement nephogram and pile-soil stress nephogram. On this basis the foundation settlement factors was analyzed systematically that focus on the elastic modulus of pile, pile spacing, pile diameter and pile length in foundation treatment, especially for the characteristics parameters of contact element. Result shows that increasing the pile modulus, pile diameter, pile length and decreasing the pile spacing is all conducive to reducing settlement. The best advice is got that the pile diameter should be not more than 0.5m, pile length not more than 27m and the pile spacing be around 2m.

scholarly journals Finite Element Analysis of Impact Energy on Spur Gear

2018 ◽  
Vol 225 ◽  
pp. 06011 ◽  
Author(s):  
Ismail Ali Bin Abdul Aziz ◽  
Daing Mohamad Nafiz Bin Daing Idris ◽  
Mohd Hasnun Arif Bin Hassan ◽  
Mohamad Firdaus Bin Basrawi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Impact Energy ◽  
High Speed ◽  
Impact Test ◽  
Impact Load ◽  
Gear Tooth ◽  
Test Equipment ◽  
Element Analysis ◽  
The Impact

In high-speed gear drive and power transmission, system impact failure mode always occurs due to the sudden impact and shock loading during the system in running. Therefore, study on the amount of impact energy that can be absorbed by a gear is vital. Impact test equipment has been designed and modelled for the purpose to study the impact energy on gear tooth. This paper mainly focused on Finite Element Analysis (FEA) of impact energy that occurred during simulation involving the impact test equipment modelling. The simulation was conducted using Abaqus software on critical parts of the test equipment to simulate the impact event and generate impact data for analysis. The load cell in the model was assumed to be free fall at a certain height which gives impact load to the test gear. Three different type of material for the test gear were set up in this simulation. Results from the simulation show that each material possesses different impact energy characteristic. Impact energy values increased along with the height of load drop. AISI 1040 were found to be the toughest material at 3.0m drop that could withstand up to 44.87N.m of impact energy. These data will be used to validate data in physical experiments in further study.

Finite Element Analysis of Bridge-Foundation Interaction System under Horizontal Seismic Excitation

2014 ◽  
Vol 490-491 ◽  
pp. 691-694
Author(s):  
Shou Long Chen ◽  
Chun Yi Cui ◽  
Yan Sun
Keyword(s):  
Finite Element ◽  
Seismic Waves ◽  
Soil Depth ◽  
Soft Soil ◽  
Soil Layer ◽  
Element Analysis ◽  
Interaction System ◽  
Frequency Components ◽  
Bridge Foundation ◽  
Pile Length

Based on Newmark-β gradual integration method and elastic-plastic mechanical theory, numeriacl analyses of effects of soft soil depth and thickness and pile length on the characteristics of horizontal seismic response of bridge-foundation interaction system with soft layers conducted by using finite element program Midas/GTS. The numerical results show that: (1) The high frequency components of seismic excitations can be filtered and the low frequency components are amplified correspondingly when seismic waves are transmitted through soft soil layer, and thicker and lower soft soil layer can amplified this effects; (2)The extremum force of abutment shows decreases first then increases with depth decreasing, and displacement of abutment top and bottom has the same law with seismic waves, and the thicker and lower soft soil layer or shorter piles can aggravate abutment force and deformation; (3)Shear extremal stress shows decrease from top to bottom and the thicker and lower soft soil layer or shorter piles are adverse on piles; (4)Moment extremal expresses first increase then decrease with pile length and the lower and thicker soft soil layer or shorter piles can enlarged piles moment.

Differences of transverse impact damages in 3D angle-interlock woven composites between warp and weft directions

2019 ◽  
Vol 28 (8) ◽  
pp. 1203-1227 ◽  
Author(s):  
Chunlei Ren ◽  
Amna Siddique ◽  
Baozhong Sun ◽  
Bohong Gu
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Kink Band ◽  
Woven Composites ◽  
Hopkinson Pressure Bar ◽  
Transverse Impact ◽  
Element Analysis ◽  
The Impact ◽  
Impact Damages

Transverse impact damages of 3D angle-interlock woven composites have been tested at split Hopkinson pressure bar along warp and weft directions respectively. The impact deformation and damages were photographed with a high-speed camera. A finite element analyses model was established at mesostructure level to unveil the inner yarn, resin damages, and stress distributions. There are significant differences of yarn breakages and interface damage between the two directions. From finite element analysis simulations and scanning electron microscope photographs, we found the warp yarns were in kink band deformation and shear damage, while the weft yarns were in compressive failure and had smooth fractography. The warp yarns which run through-thickness directions impede transverse impact crack propagations in resins and lead to high delamination resistances. The straight weft yarns impart high stiffness and strength to in-plane directions.

3D Finite Element Analysis on Behaviour of Piled Raft Foundations

2014 ◽  
Vol 580-583 ◽  
pp. 3-8 ◽  
Author(s):  
Anhtuan Vu ◽  
Ducphong Pham ◽  
Tuonglai Nguyen ◽  
Yu He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
3D Finite Element ◽  
3D Finite Element Analysis ◽  
Pile Spacing ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Pile Length

This paper highlights settlement behaviour of piled raft foundation by 3D finite element analysis through Plaxis 3D Foundation program. The effects of pile number, pile length, pile layout and pile spacing on the behaviour of piled raft foundation were studied. The numerical results show that: Piled raft foundation has much more efficency to reduce settlement than that of traditional raft foundation. The value of vertical defomation decreases as the result of the increase of pile number, pile length, pile spacing and vice versa. Pile layout has significant effect on both value and location of maximum settlement of piled raft foundation.

Finite Element Analysis and Calculation of Load Capacity on Aerostatic Thrust Bearing

2011 ◽  
Vol 188 ◽  
pp. 566-571
Author(s):  
P.C. Shu ◽  
S.H. Xiao ◽  
H. Wu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Hydrodynamic Effect ◽  
Element Analysis ◽  
Ultra High Speed ◽  
The Impact ◽  
Aerostatic Spindle

For the design and application of ultra-high speed aerostatic spindle, it is often difficult to determine the load capacity of bearing gas film because of nonlinear problem, especially when the gas film is very thin. As ultra-high speed aerostatic spindle is working, rotational velocity of spindle ranges up to 300,000 rpm, while Reynolds number of air flow also increases in aerostatic bearing, so we need to consider the impact of gas inertia on the load capacity. In order to improve design accuracy of ultra-high speed aerostatic spindle, it is vitally necessary to consider hydrodynamic effect of aerostatic bearings. By using finite element analysis software ANSYS software as analysis platform, through finite element the analysis of the internal flow field of aerostatic thrust bearing, this paper obtains the relationship of rotation speed and load capacity of aerostatic thrust bearing.

ROTOR RESONANCES ANALYSES OF HIGH-SPEED HIGH POWER PERMANENT-MAGNET ELECTRICAL MACHINES

2021 ◽  
pp. 95-108
Author(s):  
Wedad Alsadiq Alhawil ◽  
Ali A. Mehna ◽  
Asheraf Eldieb ◽  
Tarak Assaleh
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
High Speed ◽  
Natural Frequencies ◽  
Design Stage ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
The Impact

High-speed electric machines (HSEMs) have been widely used in many of today’s applications.  For high-speed machines, in particular, it is very important to accurately predict natural frequencies of the rotor at the design stage to minimize the likelihood of failure. The main goal of this study is examine the design issues and performance of high-speed machines. For permanent-magnet synchronous motors (PMSM) driven by high-frequency drives, the rotor speed is normally above 30 000 rpm and it may exceed 100 000 rpm.  This study examined a 7-kw permanent magnet synchronous machine at 200,000 rpm. 3D finite element analysis (ANSYS WORKBENCH 15) was conducted to determine the natural frequencies and rotor patterns of a synchronous high-speed permanent magnetic motor, to assess the impact of leading design parameters, such as length, column diameter, span, bearings, material properties, and to compare the results of the finite element program with the results of analytical methods (i.e. critical speed).

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

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