scholarly journals Explanation and Application of the Evolving Contact Traction Fields in Shallow Foundation Systems

Geotechnics ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 91-113
Author(s):  
Adam G. Taylor ◽  
Jae H. Chung
Keyword(s):  
Granular Materials ◽  
Sensitivity Study ◽  
Elastic Half Space ◽  
Shallow Foundation ◽  
Stress Fields ◽  
Stress Distributions ◽  
Modelling Method ◽  
Semi Empirical ◽  
Physical Phenomena ◽  
Qualitative Discussion

The present paper provides a qualitative discussion of the evolution of contact traction fields beneath rigid shallow foundations resting on granular materials. A phenomenological similarity is recognized in the measured contact traction fields of rigid footings and at the bases of sandpiles. This observation leads to the hypothesis that the stress distributions are brought about by the same physical phenomena, namely the development of arching effects through force chains and mobilized intergranular friction. A set of semi-empirical equations are suggested for the normal and tangential components of this contact traction based on past experimental measurements and phenomenological assumptions of frictional behaviors at the foundation system scale. These equations are then applied to the prescribed boundary conditions for the analysis of the settlement, resistance, and stress fields in supporting granular materials beneath the footing. A parametric sensitivity study is performed on the proposed modelling method, highlighting solutions to the boundary-value problems in an isotropic, homogeneous elastic half-space.

scholarly journals Photogrammetric Process to Monitor Stress Fields Inside Structural Systems

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4023
Author(s):  
Leonardo M. Honório ◽  
Milena F. Pinto ◽  
Maicon J. Hillesheim ◽  
Francisco C. de Araújo ◽  
Alexandre B. Santos ◽  
...  
Keyword(s):  
Boundary Element ◽  
Real Time ◽  
Stress Fields ◽  
Structural Systems ◽  
Unknown Boundary ◽  
Stress Distributions ◽  
Displacement Fields ◽  
Time Stress ◽  
Beam Surface ◽  
Measured Displacement

This research employs displacement fields photogrammetrically captured on the surface of a solid or structure to estimate real-time stress distributions it undergoes during a given loading period. The displacement fields are determined based on a series of images taken from the solid surface while it experiences deformation. Image displacements are used to estimate the deformations in the plane of the beam surface, and Poisson’s Method is subsequently applied to reconstruct these surfaces, at a given time, by extracting triangular meshes from the corresponding points clouds. With the aid of the measured displacement fields, the Boundary Element Method (BEM) is considered to evaluate stress values throughout the solid. Herein, the unknown boundary forces must be additionally calculated. As the photogrammetrically reconstructed deformed surfaces may be defined by several million points, the boundary displacement values of boundary-element models having a convenient number of nodes are determined based on an optimized displacement surface that best fits the real measured data. The results showed the effectiveness and potential application of the proposed methodology in several tasks to determine real-time stress distributions in structures.

scholarly journals Interior-stress fields produced by a general axisymmetric punch

Friction ◽  
2021 ◽  
Author(s):  
Longxiang Yang ◽  
Zhanjiang Wang ◽  
Weiji Liu ◽  
Guocheng Zhang ◽  
Bei Peng
Keyword(s):  
Hankel Transform ◽  
Elastic Half Space ◽  
Stress Fields ◽  
Dual Integral Equations ◽  
Total Load ◽  
Interior Stress ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Relationship Of ◽  
Analytical Expressions

AbstractThis work is a supplement to the work of Sneddon on axisymmetric Boussinesq problem in 1965 in which the distributions of interior-stress fields are derived here for a punch with general profile. A novel set of mathematical procedures is introduced to process the basic elastic solutions (obtained by the method of Hankel transform, which was pioneered by Sneddon) and the solution of the dual integral equations. These processes then enable us to not only derive the general relationship of indentation depth D and total load P that acts on the punch but also explicitly obtain the general analytical expressions of the stress fields beneath the surface of an isotropic elastic half-space. The usually known cases of punch profiles are reconsidered according to the general formulas derived in this study, and the deduced results are verified by comparing them with the classical results. Finally, these general formulas are also applied to evaluate the von Mises stresses for several new punch profiles.

scholarly journals Heat transfer simulation of the cure of thermoplastic particle interleaf carbon fibre epoxy prepregs

2018 ◽  
Vol 53 (15) ◽  
pp. 2053-2064 ◽  
Author(s):  
Tassos Mesogitis ◽  
James Kratz ◽  
Alex A Skordos
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Sensitivity Study ◽  
Process Models ◽  
Analysis Techniques ◽  
New Class ◽  
Thermosetting Polymers ◽  
Heat Transfer Simulation ◽  
Thermal Analysis Techniques ◽  
Semi Empirical

Thermochemical properties are needed to develop process models and define suitable cure cycles to convert thermosetting polymers into rigid glassy materials. Uncertainty surrounding the suitability of thermal analysis techniques and semi-empirical models developed for conventional composite materials has been raised for the new class of particle interleaf materials. This paper describes kinetics, conductivity, heat capacity and glass transition temperature measurements of HexPly® M21 particle interleaf material. Thermal models describing conventional, non-particle epoxy systems were fit to the data and validated through a thick-section cure. Results from curing experiments agree with heat transfer simulation predictions, indicating that established thermal analysis techniques and models can describe polymerisation and evolving material properties during processing of a material representing the class of interleaf toughened systems. A sensitivity study showed time savings up to about 20%, and associated energy-efficiency-productivity benefits can be achieved by using cure simulation for particle interleaf materials.

Models of pressure compaction and their application for wheat meal

2014 ◽  
Vol 28 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Stanisław Skonecki ◽  
Ryszard Kulig ◽  
Grzegorz Łysiak
Keyword(s):  
Moisture Content ◽  
Granular Materials ◽  
Plant Material ◽  
Experimental Results ◽  
Plant Origin ◽  
Model Equations ◽  
Physical Phenomena

Abstract Processes of compaction of granular materials were described using selected models. The analysis of their accuracy on the example of wheat was the basis for the discussion on their applicability to the processing of plant-origin materials. Parameters of the model equations for wheat, compressed at 10-18% moisture content were calculated, and the relations between these parameters and wheat moisture were determined. It was found that the analyzed models described the pressure compaction of granular plant material with different accuracy, and were highly dependent on moisture. The study also indicated that the model of Ferrero et al. fits the experimental results well. The parameters of this model reflected very well the physical phenomena which occur during compression.

Stress Analysis and Life Estimation of Drawing Die with Bi-Materials

2010 ◽  
Vol 156-157 ◽  
pp. 1415-1420
Author(s):  
Zhong Zheng ◽  
Hai Ou Zhang ◽  
Gui Lan Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Fields ◽  
Drawing Process ◽  
Stress Distributions ◽  
Life Estimation ◽  
Drawing Die ◽  
Die Material ◽  
The Cost ◽  
Realistic Significance

In this article, a drawing die is researched in order to obtain the dynamic load and stress distributions and determine the potential fatigue location in it. The stress fields of the drawing die in the drawing process and their changing rules were studied through finite element method. The dynamic simulation of stress changing state has been realized, and the potential fatigue locations in the die were also determined. Based on the conclusion, the cavity die was divided into the substrate part and the wear-resistant part according to the stress distribution. Fatigue life estimations were made on the homogeneous die and the die with bi-materials. The example showed that bi-materials design can increase the service life while greatly reduces the cost of die material. The conclusions drawn conform to reality and have realistic significance.

Construction of Multi-Domain System Simulation Model for Trade Studies in System Design Considering Multiple Scenes

2019 ◽  
Author(s):  
Kazuya Oizumi ◽  
Keita Ishida ◽  
Yoshihiro Uchibori ◽  
Kazuhiro Aoyama
Keyword(s):  
Simulation Model ◽  
System Design ◽  
Systems Engineering ◽  
System Simulation ◽  
Cognitive Model ◽  
Simulation Models ◽  
Modelling Method ◽  
Variable Transmission ◽  
Physical Phenomena ◽  
Model Based Systems Engineering

Abstract As a product is sold globally, usages of the product have much wider variety. Thus, a product needs to be designed considering multiple scenes. To certify that the product performs properly in any scene, industries started to apply Model Based Systems Engineering (MBSE). Whereas multi-domain system simulations are regarded as a prominent approach for the system design of a product, construction of model depends on knowledge and sense modelers. This paper proposes a modelling method to construct appropriate multi-domain system simulation models while reducing dependencies to senses of modelers. The proposed method comprises two parts. First, significant tradeoffs to be studied by the simulation are specified. Second, features of simulation models are deliberated for specified tradeoffs. To specify significant tradeoffs, product and scenes where the product is used are integrated into a model. Further, to deliberate features of simulation model, cognitive model of physical phenomena in a product is employed as well. The proposed method was applied to the development of continuously variable transmission to verify its validity.

Incremental stress under a two-dimensional artificial lake

1969 ◽  
Vol 6 (5) ◽  
pp. 1067-1075 ◽  
Author(s):  
D. I. Gough
Keyword(s):  
Seismic Activity ◽  
Elastic Half Space ◽  
Two Dimensional ◽  
Stress Distributions ◽  
Artificial Lake ◽  
Peace River ◽  
Artificial Lakes ◽  
Dimensional Approximation ◽  
Stress Components ◽  
Stress Parameters

Seismic activity has been induced by loading and possibly lubrication of faults in rocks underlying several artificial lakes. Such evidence of failure justifies study of incremental stress distributions produced by the filling of artificial lakes. In this paper two-dimensional lakes are considered. Equations are derived giving the incremental stress components due to a side of a water-filled trough of polygonal section in the surface of art elastic half-space. A computer program based on these equations is described. Distributions of stress parameters are shown for lakes of rectangular and isosceles triangular sections, and for a two-dimensional approximation of a section of the lake forming behind the Bennett Dam on the Peace River, British Columbia.

Analysis of the off-corner subsurface cracks of continuous casting blooms under the influence of soft reduction and controllable approaches by a chamfer technology

2019 ◽  
Vol 116 (3) ◽  
pp. 310 ◽  
Author(s):  
Nanfu Zong ◽  
Hui Zhang ◽  
Yang Liu ◽  
Zhifang Lu
Keyword(s):  
Continuous Casting ◽  
Cross Section ◽  
Mechanical Model ◽  
Stress Fields ◽  
Temperature History ◽  
Stress Distributions ◽  
Soft Reduction ◽  
Reduction Operation ◽  
Subsurface Cracks ◽  
Reduction Region

In the current study, the morphology of the off-corner subsurface cracks located on the cross section of continuous casting bloom under a soft reduction operation was observed. A 3D thermo-mechanical model was adopted to calculate the temperature history, bulging deformation and stress distributions in the reduction region, and then to analyze the formation of the off-corner subsurface cracks under the influence of soft reduction. The results showed that the off-corner subsurface cracks can be formed under the influence of the extensive stress fields which develop in the cracking temperature range, especially located on the loosed side of the bloom corner region. Adjusting the chamfer angle and chamfer length can decrease stress concentration and bulging deformation to minimize the risk of off-corner subsurface cracks during the soft reduction operation.

Wave propagation from extended, asymmetric surface sources in an elastic half-space

1979 ◽  
Vol 69 (3) ◽  
pp. 713-735
Author(s):  
N. C. Maiti ◽  
M. Mitra
Keyword(s):  
Wave Propagation ◽  
Half Space ◽  
Surface Displacement ◽  
Elastic Half Space ◽  
Stress Distributions ◽  
Surface Motion ◽  
Common Features ◽  
Exact Determination

abstract A procedure is given for the exact determination of the displacement produced in a half-space by arbitrary stresses acting on the surface. Solutions have been obtained for three different impulsive stress distributions acting on a circular portion of the surface and some common features of the solutions are examined. Numerical values of the surface displacement are exhibited graphically in the three cases showing that the pulses comprising the surface motion are oscillatory.

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