scholarly journals A numerical parametric study on the efficiency of prestressed geogrid reinforced soil

2020 ◽  
Vol 205 ◽  
pp. 12004
Author(s):  
Soukat Kumar Das ◽  
N. K. Samadhiya
Keyword(s):  
Energy Requirement ◽  
Reinforced Soil ◽  
Shallow Foundation ◽  
Finite Element Program ◽  
Load Bearing ◽  
Total Input ◽  
Ground Conditions ◽  
Element Program ◽  
Numerical Parametric Study ◽  
The Impact

Prestressing geosynthetics offers a rapid and safe method of improving the poor ground conditions. This paper aims to find out the effect of prestressing the geogrid layer on load bearing and settlement performance. This study also takes into account the impact of the size, depth of placement and the adjacency of footing, for unreinforced (UR), geogrid reinforced (GR) and prestressed geogrid reinforced (PGR) soil on the load-bearing and the settlement characteristics by using the finite element program Plaxis 3D. Based on numerical simulation, it appears that PGR soil can enhance the bearing pressure of the UR soil by almost 500% and reduced the settlement by nearly 88 % by reducing the energy consumption. The footing placed at higher depths for PGR soil gives better performance as compared to GR soil. Moreover, placing two adjacent square footing increases the interference zone of PGR soil by 67% as compared to UR soil. This method can be instrumental in reducing the total input energy requirement to achieve a certain settlement during placement of shallow foundation for various important structures while being economic simultaneously.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Investigation of Impact of New Design Code on Riser System Design

2009 ◽  
Author(s):  
Alan Yu ◽  
Paul Stanton ◽  
Yongming Cheng
Keyword(s):  
System Design ◽  
Production Systems ◽  
Design Code ◽  
Finite Element Program ◽  
Stress Evaluation ◽  
Element Program ◽  
Steel Catenary Risers ◽  
Ease Of Access ◽  
The Impact ◽  
Gas Lift

Top tensioned risers are fluid conduits from subsea equipment to surface floating production platforms. The advantages of using top tensioned risers are the ability to drill and complete through the production riser, ease of access of the production trees for gas lift operation, and the simplicity of workover and redrill. The integrity of a riser system plays an important role in deepwater developments. Top tensioned risers (TTRs) and steel catenary risers (SCRs) have been widely used with floating production systems such as Spars and TLPs. API RP 2RD [1] has been used to guide riser system design for the last decade. API RP 2RD is being revised as a code (ISO 13628-12) that will also be adopted as a new API code. This paper investigates the impacts of the new design code on the riser system design. This paper first discusses the differences between ISO/WD 13628-12 and the existing API RP 2RD code, particularly the section on design criteria for pipes. The Holstein top tensioned riser system is chosen as an example to evaluate the riser system design impacts. The risers have been installed and successfully producing oil since 2005. The results of the nonlinear finite element program ABAQUS used to analyze the Holstein top tensioned risers were evaluated according to the API RP 2RD. The same analytical results are used for evaluating the impact of the proposed ISO 13628-12 in the area of stress evaluation.

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.

scholarly journals PLASTIC CAPACITY OF BOLTED RHS FLANGE-PLATE JOINTS UNDER AXIAL TENSION

2016 ◽  
Vol 8 (3) ◽  
pp. 85-93
Author(s):  
Andrej Mudrov ◽  
Gintas Šaučiuvėnas ◽  
Antanas Sapalas ◽  
Ivar Talvik
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Load Bearing Capacity ◽  
Finite Element Program ◽  
Load Bearing ◽  
Axial Tension ◽  
Flange Thickness ◽  
Element Program ◽  
Two Sides ◽  
Ansys Workbench

This article considers the calculation of load-bearing capacity of flange-plate joints with bolts along two sides of rectangular hollow sections (RHS) under axial tension. It provides a review and comparison of various calculation methodologies for establishing the load-bearing capacity of RHS flange-plate joints, such as suggested in EN 1993-1-8:2005 and STR 2.05.08:2005 as well as those proposed in different countries and by other authors. Common design principles and derived results for load-bearing capacity of flange-plate joints have been analysed and compared. Following the numerical modelling, which has been done using ANSYS Workbench finite element program, the derived results for load-bearing capacity have been compared with analytical load-bearing capacity results for flange-plate joints of the same structure. The analysis has focused on one type of flange-plate joints with bolts – both preloaded and non-preloaded – along two opposite sides of the tube, with the flange thickness of 15 mm and 25 mm.

Predicting the Impact of Quenching on Mechanical Properties of Complex-Shaped Aluminum Alloy Parts

1995 ◽  
Vol 117 (2) ◽  
pp. 479-488 ◽  
Author(s):  
D. D. Hall ◽  
I. Mudawar
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Boundary Conditions ◽  
Finite Element Program ◽  
Part Geometry ◽  
Heat Treated ◽  
Element Program ◽  
Nozzle Configuration ◽  
The Impact

The mechanical properties of age-hardenable aluminum alloy extrusions are critically dependent on the rate at which the part is cooled (quenched) after the forming operation. The present study continues the development of an intelligent spray quenching system, which selects the optimal nozzle configuration based on part geometry and composition such that the magnitude and uniformity of hardness (or yield strength) is maximized while residual stresses are minimized. The quenching of a complex-shaped part with multiple, overlapping sprays was successfully modeled using spray heat transfer correlations as boundary conditions within a finite element program. The hardness distribution of the heat-treated part was accurately predicted using the quench factor technique; that is, the metallurgical transformations that occur within the part were linked to the cooling history predicted by the finite element program. This study represents the first successful attempt at systematically predicting the mechanical properties of a quenched metallic part from knowledge of only the spray boundary conditions.

Effect of Cushion Layers on Mechanical Characteristics of Spiral Case Structure in Hydropower Station

2013 ◽  
Vol 351-352 ◽  
pp. 897-900
Author(s):  
Bo Liu ◽  
Jian Hua Liu ◽  
Zhe Wang
Keyword(s):  
Mechanical Characteristics ◽  
Poisson Ratio ◽  
Water Pressure ◽  
Deformation Modulus ◽  
Hydropower Station ◽  
Finite Element Program ◽  
Load Bearing ◽  
Spiral Case ◽  
Element Program ◽  
Cushion Layer

The effects of deformation modulus, thickness and range of cushion layer on mechanical characteristics of spiral case in hydropower station has been analyzed using the finite element program ANSYS and nonlinear contact theory. The result shows that when cushion layer scope and poisson ratio is fixed, as the elastic modulus of cushion layer decreases, the deformation and stress of spiral case increases, surrounding concrete load-bearing ratio of water pressure reduces. If the cushion layer deformation modulus is fixed and the range of cushion layer extends to 10 degree site bellow the waist of spiral case, the steel spiral case stress decrease, the radial stress transferred from the spiral case to surrounding concrete increase by about from 0.01MPa to 0.03MPa, and load-bearing ratio of concrete increase, when the cushion layer Poisson ratio increases from 0.25 to 0.35.

Analysis on Axial Compression Ratio to Strong Column Weak Beam Effect in Framework Node

2014 ◽  
Vol 578-579 ◽  
pp. 16-19
Author(s):  
Xin Wen ◽  
Ze Jing Hao ◽  
Xing Guo Wang
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Pressure Ratio ◽  
Finite Element Program ◽  
Static State ◽  
Axial Compression Ratio ◽  
Weak Beam ◽  
Element Program ◽  
The Impact

Nodes of Column ends, included ordinary Intermediate nodes and nodes in the model of carbon fiber, have been established based on finite element program, have analyzed the comparison of the deformation, bearing capacity, ductility in Quasi static state under three conditions of axial compression ratio reinforcement (0.2, 0.4, 0.6) between reinforcement nodes and ordinary nodes, have researched the impact caused by the change of axial pressure ratio on seismic performance of node, The result have shown that size of the axial compression ratio and bearing capacity of reinforced nodes follow basic plastics performance, but ductility of nodes in low axial compression ratio is more effective.

Property determination and wave propagation in a block of Barre granite

1977 ◽  
Vol 67 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Werner Goldsmith ◽  
J. L. Sackman ◽  
R. L. Taylor
Keyword(s):  
Wave Propagation ◽  
Finite Element Program ◽  
In Situ Calibration ◽  
Propagation Analysis ◽  
Principal Axes ◽  
Element Program ◽  
Principal Directions ◽  
Calibration Techniques ◽  
Barre Granite ◽  
The Impact

abstract The principal axes of a 666.8 by 609.6 by 489.0 mm (2614 in by 24 in by 1914 in) block of Barre granite, treated as an orthotropic elastic material were determined from measured pulse velocities along directions connecting 160 pairs of surface points, encompassing the entire spectrum of possible orientations. The elastic moduli of the rock were ascertained by Hopkinson bar tests involving rods cored from other samples along their principal directions; this was required for the execution of a wave-propagation analysis in the block treated as a half-space. Construction and insertion techniques were developed for transducers to be embedded in the rock at 14 locations. External and internal calibration procedures were devised to permit interpretation of the data transmitted from the interior of the sample. Transients in the block were generated by the impact of 6.35-mm (14 in) diameter steel spheres on loading bars sandwiching a thin quartz disk, serving as an input transducer, against the specimen. The wave patterns sensed by the transducers were displayed and photographed on oscillographic screens. A finite element program capable of handling arbitrary anisotropy was developed and employed for comparing the experimental results with analytical predictions based on the measured input as the boundary condition. For those stations where computations were performed, the correlation ranged from good to qualitative. It is concluded that better transducer embedment and in situ calibration techniques are required for internal transducers used in hard rocks of this type.

Computer Simulation of Dynamic Impact Processes: A Visual and Audio Presentation

1991 ◽  
Author(s):  
Wing L. Cheng ◽  
Alan Craig ◽  
Ilhan Dilber
Keyword(s):  
Numerical Approach ◽  
Scientific Data ◽  
Finite Element Program ◽  
Impact Processes ◽  
3D Geometry ◽  
Element Program ◽  
Tremendous Amount ◽  
The Impact ◽  
Impact Events ◽  
Dynamic Phenomena

Abstract Complicated dynamic phenomena as occurred in high velocity impact processes were studied using a numerical approach. A transient nonlinear finite element program was used to model and simulate the impact events. The use of supercomputers was required in these simulations due to the size of the problem and the duration of the events. Techniques designed to visualize 3D geometry as well as scientific data were developed to help researchers make sense out of the tremendous amount of data generated by the supercomputers. Resulting animation sequences provided a means to the researchers to study these dynamic processes. A newly developed technique called data sonification was also exploited to provide an additional medium to display scientific data. This is accomplished by mapping various parameters of the dataset to various parameters of sound. Two complex 3D numerical examples were used to demonstrate both visual and sonic techniques.

scholarly journals Improving Blast Performance of Reinforced Concrete Panels Using Sacrificial Cladding with Hybrid-Multi Cell Tubes

Modelling ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 149-165
Author(s):  
Mahmoud Abada ◽  
Ahmed Ibrahim ◽  
S.J. Jung
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Plate Thickness ◽  
Core Layer ◽  
Engineering Structures ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Element Program ◽  
Thin Walled ◽  
The Impact

The utilization of sacrificial layers to strengthen civilian structures against terrorist attacks is of great interest to engineering experts in structural retrofitting. The sacrificial cladding structures are designed to be attached to the façade of structures to absorb the impact of the explosion through the facing plate and the core layer progressive plastic deformation. Therefore, blast load striking the non-sacrificial structure could be attenuated. The idea of this study is to construct a sacrificial cladding structure from multicellular hybrid tubes to protect the prominent bearing members of civil engineering structures from blast hazard. The hybrid multi-cell tubes utilized in this study were out of staking composite layers (CFRP) around thin-walled tubes; single, double, and quadruple (AL) thin-walled tubes formed a hybrid single cell tube (H-SCT), a hybrid double cell tube (H-DCT), and a hybrid quadruple cell tube (H-QCT). An unprotected reinforced concrete (RC) panel under the impact of close-range free air blast detonation was selected to highlight the effectiveness of fortifying structural elements with sacrificial cladding layers. To investigate the proposed problem, Eulerian–Lagrangian coupled analyses were conducted using the explicit finite element program (Autodyn/ANSYS). The numerical models’ accuracy was validated with available blast testing data reported in the literature. Numerical simulations showed a decent agreement with the field blast test. The proposed cladding structures with different core topologies were applied to the unprotected RC slabs as an effective technique for blast loading mitigation. Mid-span deflection and damage patterns of the RC panels were used to evaluate the blast behavior of the structures. Cladding structure achieved a desired protection for the RC panel as the mid-span deflection decreased by 62%, 78%, and 87% for H-SCT, H-DCT, and H-QCT cores, respectively, compared to the unprotected panels. Additionally, the influence of the skin plate thickness on the behavior of the cladding structure was investigated.

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