scholarly journals Survivability of Suddenly Loaded Arrays of Micropillars

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7173
Author(s):  
Tomasz Derda ◽  
Zbigniew Domanski
Keyword(s):  
Applied Load ◽  
Load Transfer ◽  
Multicomponent System ◽  
Compressive Load ◽  
Stable Configuration ◽  
Model Framework ◽  
Sharing Rule ◽  
Flat Substrate ◽  
The Family ◽  
Sudden Loading

When a multicomponent system is suddenly loaded, its capability of bearing the load depends not only on the strength of components but also on how a load released by a failed component is distributed among the remaining intact ones. Specifically, we consider an array of pillars which are located on a flat substrate and subjected to an impulsive and compressive load. Immediately after the loading, the pillars whose strengths are below the load magnitude crash. Then, loads released by these crashed pillars are transferred to and assimilated by the intact ones according to a load-sharing rule which reflects the mechanical properties of the pillars and the substrate. A sequence of bursts involving crashes and load transfers either destroys all the pillars or drives the array to a stable configuration when a smaller number of pillars sustain the applied load. By employing a fibre bundle model framework, we numerically study how the array integrity depends on sudden loading amplitudes, randomly distributed pillar strength thresholds and varying ranges of load transfer. Based on the simulation, we estimate the survivability of arrays of pillars defined as the probability of sustaining the applied load despite numerous damaged pillars. It is found that the resulting survival functions are accurately fitted by the family of complementary cumulative skew-normal distributions.

Uplift behaviour of tapered piles established from model tests

2000 ◽  
Vol 37 (1) ◽  
pp. 56-74 ◽  
Author(s):  
M Hesham El Naggar ◽  
Jin Qi Wei
Keyword(s):  
Load Transfer ◽  
Compressive Loading ◽  
Compressive Load ◽  
Tensile Load ◽  
Confining Pressure ◽  
Cohesionless Soil ◽  
Uplift Capacity ◽  
Experimental Modelling ◽  
Confining Pressures ◽  
Load Tests

Tapered piles have a substantial advantage with regard to their load-carrying capacity in the downward frictional mode. The uplift performance of tapered piles, however, has not been fully understood. This paper describes the results of an experimental investigation into the characteristics of the uplift performance of tapered piles. Three instrumented steel piles with different degrees of taper were installed in cohesionless soil and subjected to compressive and tensile load tests. The soil was contained in a steel soil chamber and pressurized using an air bladder to facilitate modelling the confining pressures pertinent to larger embedment depths. The results of this study indicated that the pile axial uplift capacity increased with an increase in the confining pressure for all piles examined in this study. The ratios of uplift to compressive load for tapered piles were less than those for straight piles of the same length and average embedded diameter. The uplift capacity of tapered piles was found to be comparable to that of straight-sided wall piles at higher confining pressure values, suggesting that the performance of actual tapered piles (with greater length) would be comparable to that of straight-sided wall piles. Also, the results indicated that residual stresses developed during the compressive loading phase and their effect were more significant on the initial uplift capacity of piles, and this effect was more pronounced for tapered piles in medium-dense sand.Key words: tapered piles, uplift, axial response, load transfer, experimental modelling.

Gender and Water

2019 ◽  
pp. 433-452
Author(s):  
Mononita Kundu Das ◽  
Rituparna Das
Keyword(s):  
Wage Gap ◽  
Water Shortage ◽  
Utility Functions ◽  
Model Framework ◽  
Welfare Implication ◽  
Female Workers ◽  
Behavioural Model ◽  
The Family ◽  
Gender Based ◽  
Unorganized Sector

This chapter examines the welfare implication of wage revisions for two Indian unorganized sector female workers with opposite preference patterns for income and leisure in drought-prone zone. The female workers here face a gender-based wage gap and the inconveniences caused by water shortage adversely affect their effective incomes since females are the major users of water in the family. This chapter also makes a couple of recommendations for policymakers and legislators. It experiments with alternative utility functions in neoclassical microeconomic behavioural model framework.

scholarly journals DEPENDENCE OF CRACK FORMATION ON CRYSTALLOGRAPHIC ORIENTATION FOR ICE

1966 ◽  
Vol 44 (11) ◽  
pp. 2757-2764 ◽  
Author(s):  
L. W. Gold
Keyword(s):  
Grain Boundary ◽  
Crystallographic Orientation ◽  
Basal Plane ◽  
Applied Load ◽  
Crack Formation ◽  
Compressive Load ◽  
Slip Systems ◽  
Polycrystalline Ice ◽  
Minimum Number ◽  
Columnar Grain

Observations are reported of crack propagation in columnar-grain, polycrystalline ice subjected to constant compressive load applied perpendicular to the long axis of the columns. About three-quarters of the cracks observed were transcrystalline and the remainder occurred at grain boundaries. The plane of the cracks tended to be parallel to the direction of the applied load. Transcrystalline cracks tended to propagate either parallel or perpendicular to the basal plane. At least two-thirds of the grain boundary cracks were associated with boundaries for which the slip plane of one or both of the adjacent grains was close to parallel or perpendicular to the boundary. It is shown that the observations are consistent with the hypothesis that a minimum number of independent slip systems are required for a grain to conform to an arbitrary deformation under constraints imposed by neighboring grains.

scholarly journals DIAGRAMS OF VACUUM INSULATING PANEL DEFORMATION DURING COMPRESSION

2019 ◽  
Vol 9 (3) ◽  
pp. 17-21
Author(s):  
Vladimir P. SELYAEV ◽  
Nikolay N. KISELEV ◽  
Oleg V. LIYASKIN
Keyword(s):  
Stress State ◽  
Load Transfer ◽  
Experimental Studies ◽  
Compressive Load ◽  
Deformation Diagram ◽  
Vacuum Insulation ◽  
Floor Slabs ◽  
Wall Panels ◽  
The Relationship ◽  
Deformation Diagrams

The possibility of using vacuum insulation panels (VIP) with a granular filler for the manufacture of threelayer enclosing wall panels, floor slabs and coatings is considered. The results of experimental studies of vacuum insulation panels, carried out with the aim of analytically describing the deformation diagrams of VIP panels under the action of a compressive load, are presented. It has been established: deformative properties of vacuum insulation panels with granular filler do not depend on the size of the filler particles, but depend on the volume content of the filler; a deformation diagram describing the relationship between stresses and relative deformations during compression of a vacuum insulating panel with a granular filler can be approximated by the function G. B. Bülfinger. The results obtained make it possible by calculation to determine the stress state in flat plating sheets during local load transfer.

Reconstruction of the interosseous ligament restores normal forearm compressive load transfer in cadavers

2005 ◽  
Vol 30 (2) ◽  
pp. 319-325 ◽  
Author(s):  
H. James Pfaeffle ◽  
Kathryne J. Stabile ◽  
Zong-Ming Li ◽  
Matthew M. Tomaino
Keyword(s):  
Load Transfer ◽  
Compressive Load ◽  
Interosseous Ligament

The Experimental Research about Vibration Compacting Load Transfer Spread in Roadbed

2012 ◽  
Vol 178-181 ◽  
pp. 1550-1554 ◽  
Author(s):  
Bao Tao Huang ◽  
Ding Liu ◽  
Fang Wang ◽  
Jie Li
Keyword(s):  
Load Transfer ◽  
Compressive Load ◽  
Contact Forces ◽  
Test Results ◽  
Vibration Load ◽  
Particle Generation ◽  
Interface Generation ◽  
Square Cells ◽  
Caustics Method ◽  
Dense State

In this paper, the caustics method was used to explore the distribution of contact forces inside a packing of discrete square cells submitted to a compressive load. The self making subroutine 3-D generation algorithm about irregular particle generation and particle contact interface generation were adopted, and irregular particles were randomly generated in the designated categories with this algorithm. The vibration compacting load diffuse and transfer law with different media dense state were analyzed. The test results show that the vibration load caused the effective compaction region was changed vertical long axis oval into the level long axis oval. The study provides an idea to research and employs a new over-loading road which better repels tired retrogression under the dynamic load.

Gender and Water

2015 ◽  
pp. 241-256
Author(s):  
Mononita Kundu Das ◽  
Rituparna Das
Keyword(s):  
Wage Gap ◽  
Water Shortage ◽  
Utility Functions ◽  
Model Framework ◽  
Welfare Implication ◽  
Female Workers ◽  
Behavioural Model ◽  
The Family ◽  
Gender Based ◽  
Unorganized Sector

This chapter examines the welfare implication of wage revisions for two Indian unorganized sector female workers with opposite preference patterns for income and leisure in drought-prone zone. The female workers here face a gender-based wage gap and the inconveniences caused by water shortage adversely affect their effective incomes since females are the major users of water in the family. This chapter also makes a couple of recommendations for policymakers and legislators. It experiments with alternative utility functions in neoclassical microeconomic behavioural model framework.

Patient specific implants for amputation prostheses: Design, manufacture and analysis

2012 ◽  
Vol 25 (04) ◽  
pp. 286-296 ◽  
Author(s):  
P. DeVasConCellos ◽  
V. K. Balla ◽  
S. Bose ◽  
R. Fugazzi ◽  
W. S. Dernell ◽  
...  
Keyword(s):  
Second Generation ◽  
Load Transfer ◽  
Mechanical Performance ◽  
Compressive Load ◽  
Fold Increase ◽  
Distal Portion ◽  
Proximal Region ◽  
Ti6al4v Alloy ◽  
Skeletal Structure ◽  
Patient Specific

SummaryObjectives: To design, manufacture and analyze custom implants with functional gradation in macrostructure for attachment of amputation prostheses.Methods: The external shape of the implant was designed by extracting geometrical data of canine cadavers from computed tomography (CT) scans to suit the bone cavity. Three generations of implant designs were developed and were optimized with the help of fit/fill and mechanical performance of implant-cadaver bone assembly using CT analysis and compression testing, respectively. A final optimized, custom Ti6Al4V alloy amputation implant, with approximately 25% porosity in the proximal region and approximaltely zero percent porosity in the distal region, was fabricated using Laser Engineered Net Shaping (LENS™) – a laser based additive manufacturing technology.Results: The proposed design changes in the second generation designs, in terms of refining thresholds, increased the average fill of the bone cavity from 58% to 83%. Addition of a flange between the stem and the head in the second generation designs resulted in more than a seven-fold increase in the compressive load carrying capacity of the assembly. Application of LENS™ in the fabrication of present custom fit Ti6Al4V alloy implants enabled incorporation of 20 to 30% porosity in the proximal region and one to two percent residual porosity in the distal portion of the implant.Clinical significance: Patient specific prostheses having direct connection to the skeletal structure can potentially aid in problems related to load transfer and proprioception in amputees. Furthermore, application of LENS™ in the fabrication of custom implants can be faster to incorporate site specific porosity and gradients for improving long-term stability.

scholarly journals Laboratory Research of Toe Resistance Based on Static Pile Load Tests in Different Schemes

2018 ◽  
Vol 28 (1) ◽  
pp. 172-181 ◽  
Author(s):  
Krzysztof Żarkiewicz
Keyword(s):  
Skin Friction ◽  
Applied Load ◽  
Load Transfer ◽  
Load Test ◽  
Laboratory Research ◽  
Load Tests ◽  
Pile Load Test ◽  
Friction Curve ◽  
Pile Load Tests ◽  
Surrounding Soil

Abstract Transfer of axial force from the head of a pile to the surrounding soil by skin friction and toe resistance is still uncertain. The results of the static pile load test are usually presented as settlement curve. This curve can be divided into two components: skin friction curve and toe resistance curve according to the settlement. Laboratory research of pile load test was carried out in two schemes: with skin friction and without skin friction. The study proved that the toe resistance with and without skin friction is not the same. Skin friction influence on toe resistance due to settlement. This phenomenon is not usually taken into account, but very often has a significant impact on axially applied load transfer. In the paper results of laboratory pile load tests id, different schemes were presented.

scholarly journals Micromechanical modeling of nacre-mimetic Ti3C2-MXene nanocomposites with viscoelastic polymer matrix

MRS Advances ◽  
2021 ◽  
Author(s):  
Shreyas Srivatsa ◽  
Pawel Packo ◽  
Leon Mishnaevsky ◽  
Tadeusz Uhl ◽  
Krzysztof Grabowski
Keyword(s):  
Polymer Matrix ◽  
Load Transfer ◽  
Matrix Material ◽  
Compressive Load ◽  
Viscoelastic Behavior ◽  
Micromechanical Modeling ◽  
Damage Resistance ◽  
Plate Elements ◽  
Brick And Mortar ◽  
Constraint Method

AbstractA new two-dimensional nanomaterial—Titanium Carbide MXene (Ti3C2-MXene)—was reported in 2011. In this work, the microscale models of Ti3C2-MXene nanomaterial are considered with polymer matrix. The nanocomposites are modeled using nacre-mimetic brick-and-mortar assembly configurations due to enhanced mechanical properties and interlocking mechanism between the Ti3C2-MXene (brick) and polymer matrices (mortar). The polymer matrix material (Epoxy-resin) is modeled with elastic and viscoelastic behavior (Kelvin–Voigt Model). The Finite Element Method is used for numerical analysis of the microscale models with the multi-point constraint method to include Ti3C2-MXene fillers in the polymer matrix. Ti3C2-MXenes are considered as thick plate elements with transverse shear effects. The response of elastic and viscoelastic models of polymer matrix are studied. Finally, a tensile and compressive load is applied at the microscale and the effective load transfer due to nacre-mimetic configuration is discussed. This paper provides nacre-mimetic models to pre-design the nanocomposite for optimal performance with damage resistance and enhanced strength.

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