Post-construction settlement estimation and increased earthwork volumes calculation of high loess fill

2016 ◽  
Vol 3 (1) ◽  
pp. 43-55
Author(s):  
Cai-Hui Zhu
Keyword(s):  
Empirical Equation ◽  
Three Dimensional ◽  
Influence Factors ◽  
In Situ Tests ◽  
Construction Time ◽  
Dimensional Finite Element ◽  
History Of ◽  
Three Dimensional Finite Element ◽  
Airport Runway ◽  
Fill Depth

In this study, the post-construction settlement (PCS) area distribution of high fill was analyzed based with reference to a case history of an airport runway crossing a deep gully reclaimed by a thick fill of loess. Earthwork volumes (EV) attributed to PCS was calculated based on in-situ tests. Results showed that the uneven PCS were related to fill depth, construction time, fill rate, integrated compaction degree, and boundary conditions. An empirical equation that considers the aforementioned influence factors was established to calculate the final PCS of high fill. The surface PCS of high fill and the EV can be estimated according to the proposed empirical equation and the original site topography using the three-dimensional finite element method.

On Predicting Softening Effects in Hard Turned Surfaces—Part II: Finite Element Modeling and Verification

2004 ◽  
Vol 127 (3) ◽  
pp. 484-491 ◽  
Author(s):  
Jing Shi ◽  
C. Richard Liu
Keyword(s):  
Finite Element ◽  
Thermal History ◽  
Three Dimensional ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Hardness Measurement ◽  
Fe Model ◽  
Dimensional Finite Element ◽  
History Of ◽  
Three Dimensional Finite Element

A material softening model based on thermal activation energy has been successfully established through tempering experiments in the first part of this study. To apply the model to predicting material softening in hard turned surfaces, the thermal history of work material is needed. In this part, a three-dimensional finite element (FE) model of machining hardened 52100 steel is constructed, and coupled thermal-stress analysis is performed to obtain the material thermal history. Then the material softening model uses the computed thermal history as input to predict the material hardness profiles along the depth into the machined surfaces. Overall, the prediction precisely catches the trend of hardness change along depth and agrees reasonably well with the hardness measurement. What’s more, the sensitivity of material softening to cutting parameters is investigated both quantitatively and qualitatively. Within the investigation range, it is observed that the increase of tool flank wear and feed rate produces severe material softening and a deeper softened layer, while the increase of cutting speed causes significant softening to the surface material but hardly changes the softened depth.

scholarly journals Influence of Disc Specimen Configuration on Its Three-Dimensional Dynamic Stress Balance

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Sheng Zhang ◽  
Bingxin Yu ◽  
Xiaojun Li ◽  
Longfei Wang ◽  
Xulong Zhang
Keyword(s):  
Dynamic Stress ◽  
Three Dimensional ◽  
Time History ◽  
Brazilian Disc ◽  
Disc Specimen ◽  
Loading Mode ◽  
Dimensional Finite Element ◽  
History Of ◽  
Three Dimensional Finite Element ◽  
Semicircular Bending

In order to investigate the dynamic stress balance of different configurations of rock specimens, three-dimensional finite element models of SHPB were established. Five types of configuration disc specimens with a diameter of 75 mm and a thickness of 30 mm were impacted at a speed of 5 m/s using a special-shaped bullet. The propagation laws of stress wave on the contact surface of the specimen-bar and the inside of the specimen were analyzed, and the time history of the stress balance factors at different positions of the specimen was obtained. The results show that the amplitudes of the transmitted waves corresponding to the five types of disc specimens with different configurations have obvious differences, and the stress propagation in the specimen has three-dimensional characteristics. According to the ease of achieving stress balance, the five configuration specimens are ordered by notched semicircular bending disc, flattened Brazilian disc, cracked straight-through flattened Brazilian disc, Brazilian disc, and cracked straight-through Brazilian disc specimen. Among them, only the first three configurations of the specimen reached the stress balance. The dynamic stress balance is affected by the disc loading mode, end contact conditions, the presence of prefabricated cracks, and disc thickness. In addition, as the disc loading end is a processed platform, it is beneficial to achieve stress balance. Prefabricated cracks are not conducive to achieving stress balance. The loading method of the notched semicircular bending disc is more conducive to achieving stress balance. This research has a certain guiding significance for selecting suitable specimen configuration and research methods to carry out rock dynamic fracture experiments.

A Study on the Influencing Factors of Deformation Control of Deformable Warheads

2012 ◽  
Vol 452-453 ◽  
pp. 160-164
Author(s):  
Ya Dong Yang ◽  
Xiang Dong Li ◽  
Yuan Zhang ◽  
Shi Yong Qin
Keyword(s):  
Phase Angle ◽  
Three Dimensional ◽  
Influence Factors ◽  
Chord Length ◽  
Time Interval ◽  
Control Parameters ◽  
Deformation Control ◽  
Dimensional Finite Element ◽  
Deformation Processes ◽  
Three Dimensional Finite Element

The deformation processes of a deformable warhead was numerically simulated using LS-DYNA three-dimensional finite element code to determine the influence factors of deformation control on the deformation quality. The relationships among optimal deformation time interval, deformation chord length, and deformation control parameters were established. The result shows that the phase angle of deforming charge should be taken within the range of 60–90°. a larger deforming charge phase angle is favorable when it comes to increasing the fragment density in the target direction. Meanwhile, the thickness of deforming charge is less important than the phase angle in terms of the influence of the deformation chord-length.

scholarly journals Investigation of Influence Factors of Wind-Induced Buffeting Response of a Six-Tower Cable-Stayed Bridge

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Zhi-Qiang Zhang ◽  
You-Liang Ding ◽  
Fang-Fang Geng
Keyword(s):  
Bridge Deck ◽  
Three Dimensional ◽  
Influence Factors ◽  
Element Model ◽  
Buffeting Response ◽  
Cable Stayed Bridge ◽  
Longitudinal Stiffness ◽  
Dimensional Finite Element ◽  
The Difference ◽  
Three Dimensional Finite Element

This paper presents an investigation of the wind-induced buffeting responses of the Jiashao Bridge, the longest multispan cable-stayed bridge in the world. A three-dimensional finite element model for the Jiashao Bridge is established using the commercial software package ANSYS and a 3D fluctuating wind field is simulated for both bridge deck and towers. A time-domain procedure for analyzing buffeting responses of the bridge is implemented in ANSYS with the aeroelastic effect included. The characteristics of buffeting responses of the six-tower cable-stayed bridge are studied in some detail, focusing on the effects including the difference in the longitudinal stiffness between the side towers and central towers, partially longitudinal constraints between the bridge deck and part of bridge towers, self-excited aerodynamic forces, and the rigid hinge installed in the middle of the bridge deck. The analytical results can provide valuable references for wind-resistant design of multispan cable-stayed bridges in the future.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Tire Modeling by Finite Elements

1992 ◽  
Vol 20 (1) ◽  
pp. 33-56 ◽  
Author(s):  
L. O. Faria ◽  
J. T. Oden ◽  
B. Yavari ◽  
W. W. Tworzydlo ◽  
J. M. Bass ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rolling Contact ◽  
Test Problems ◽  
State Behavior ◽  
Normal Contact ◽  
New Developments ◽  
Applied Torque ◽  
Dimensional Finite Element ◽  
Tire Modeling ◽  
Three Dimensional Finite Element

Abstract Recent advances in the development of a general three-dimensional finite element methodology for modeling large deformation steady state behavior of tire structures is presented. The new developments outlined here include the extension of the material modeling capabilities to include viscoelastic materials and a generalization of the formulation of the rolling contact problem to include special nonlinear constraints. These constraints include normal contact load, applied torque, and constant pressure-volume. Several new test problems and examples of tire analysis are presented.

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