Analysis of the stress-strain state of a vertical ground electrode system for permafrost soils under pushing loads

2021 ◽  
pp. 77-89
Author(s):  
I. S. Sukhachev ◽  
P. V. Chepur ◽  
A. A. Tarasenko ◽  
A. A. Gruchenkova ◽  
Yuhai Guan
Keyword(s):  
Equivalent Stress ◽  
Side Surface ◽  
Metal Structure ◽  
Vertical Displacement ◽  
Soil Mass ◽  
Electrode System ◽  
Plastic Properties ◽  
Design Scheme ◽  
Permafrost Soils ◽  
Vertical Ground

The article proposes the design, design scheme and model of a vertical ground electrode system with lobe lugs for permafrost soils. The model was implemented using the ANSYS software. In the design scheme, the soil — ground electrode system is taken into account, the elastic-plastic properties of the soil are taken into account by the Drucker — Prager model. When modeling the work of the foundation soils, the Mises strength condition was adopted, according to which the equivalent stress is calculated under the condition of the material hydrostatic compression. The following boundary conditions are accepted: a cylinder-shaped soil mass is rigidly fixed along the lower face and along the side surface of the cylinder. Calculations are made for 5 standard sizes of grounding conductors. Maps of the distribution of stresses in the metal structure of the ground electrode (the rod and petals-emphasis) are received, the movements of the ground electrode in the soil mass are determined. The dependences between the maximum equivalent stresses in the ground electrode lobes and the value of vertical displacement in the ground base are established, as well as the amount of movement of the earthing pad, at which the effective equivalent voltages reach critical values in the area where the paddles are adjacent to the rod.

scholarly journals Kinematics of Usain Bolt’s maximal sprint velocity

Kinesiology ◽  
2018 ◽  
Vol 50 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Milan Čoh ◽  
Kim Hébert-Losier ◽  
Stanko Štuhec ◽  
Vesna Babić ◽  
Matej Supej
Keyword(s):  
Ground Reaction Force ◽  
High Speed ◽  
Reaction Force ◽  
Vertical Displacement ◽  
Biomechanical Analysis ◽  
Maximal Velocity ◽  
Vertical Ground Reaction Force ◽  
Mean Velocity ◽  
Vertical Ground ◽  
Sprint Velocity

This study investigated the maximal sprint velocity kinematics of the fastest 100 m sprinter, Usain Bolt. Two high-speed video cameras recorded kinematics from 60 to 90 m during the men 100 m final at the IAAF World Challenge Zagreb 2011, Croatia. Despite a relatively slow reaction time (194 ms), Bolt won in 9.85 s (mean velocity: 10.15 m/s). His fastest 20-m section velocity was 12.14 m/s, reached between 70 and 90 m, by 2.70-m long strides and 4.36 strides/s frequency. At the maximal velocity, his contact and flight times were 86 and 145 ms, respectively, and vertical ground reaction force generated equalled 4.2 times his body weight (3932 N). The braking and propulsion phase represented 37% and 63% of ground contact, respectively, with his centre of mass (CoM) exhibiting minor reductions in horizontal velocity (2.7%) and minimal vertical displacement (4.9 cm). Emerged Bolt’s maximal sprint velocity and international predominance from coordinated motor abilities, power generation capacities, and effective technique. This study confirms that his maximal velocity was achieved by means of relatively long strides, minimal braking phase, high vertical ground reaction force, and minimal vertical displacement of CoM. This study is the first in-depth biomechanical analysis of Bolt’s maximal sprinting velocity with the segmental reconstruction.

Finite Element Analysis of the Tractor Front Axle Housing Based on ANSYS

2011 ◽  
Vol 105-107 ◽  
pp. 168-171
Author(s):  
Dong Fang Hu ◽  
Wen Hui Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Equivalent Stress ◽  
Vertical Displacement ◽  
Front Axle ◽  
Weak Links ◽  
Strength Analysis ◽  
Element Analysis ◽  
Design And Optimization ◽  
Structural Improvement

This paper shows the static strength analysis of the tractor front axle housing by using of the finite element analysis software ANSYS, visually shows equivalent stress and strain distribution and vertical displacement distribution of the front axle housing. At the same time it also shows the analysis results of the model processing, the results of accuracy and reliability, and the weak links of the structure. By analyzing the weakest link and the difference in strength between each node for the overall structure in the condition, it can provide a direction and theoretical basis for the design and optimization of geometric entities. And the results of the analysis may be as the basis for structural improvement. In this way, it can be verified that using computer virtual software for product development is positive.

scholarly journals Footwear Affects Conventional and Sumo Deadlift Performance

Sports ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Kevin A. Valenzuela ◽  
Kellie A. Walters ◽  
Elizabeth L. Avila ◽  
Alexis S. Camacho ◽  
Fany Alvarado ◽  
...  
Keyword(s):  
Vertical Velocity ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Work Load ◽  
Vertical Displacement ◽  
Improve Performance ◽  
Vertical Ground Reaction Force ◽  
Training Modality ◽  
Vertical Ground ◽  
Improved Performance

Barefoot weightlifting has become a popular training modality in recent years due to anecdotal suggestions of improved performance. However, research to support these anecdotal claims is limited. Therefore, the purpose of this study was to assess the differences between the conventional deadlift (CD) and the sumo deadlift (SD) in barefoot and shod conditions. On day one, one-repetition maximums (1 RM) were assessed for thirty subjects in both the CD and SD styles. At least 72 h later, subjects returned to perform five repetitions in four different conditions (barefoot and shod for both CD and SD) at 70% 1 RM. A 2 × 2 (footwear × lifting style) MANOVA was used to assess differences between peak vertical ground reaction force (VGRF), total mechanical work (WORK), barbell vertical displacement (DISP), peak vertical velocity (PV) and lift time (TIME) during the concentric phase. The CD displayed significant increases in VGRF, DISP, WORK, and TIME over the SD. The shod condition displayed increased WORK, DISP, and TIME compared to the barefoot condition. This study suggests that lifting barefoot does not improve performance as no differences in VGRF or PV were evident. The presence of a shoe does appear to increase the DISP and WORK required to complete the lift, suggesting an increased work load is present while wearing shoes.

scholarly journals Structural-technological solutions for the construction of roads on permafrost soils

2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Aleksei Makarov ◽  
Alexey Kraev ◽  
Zurab Shankhoev
Keyword(s):  
Numerical Modeling ◽  
Thermal Regime ◽  
Soil Mass ◽  
Frozen Soil ◽  
Thermal Mode ◽  
Technological Solution ◽  
The Road ◽  
Permafrost Soils ◽  
Engineering Principle ◽  
Nenets Autonomous

In this article, the authors briefly reviewed the problem of building roads on permafrost soils, according to the first engineering principle. The probable causes, affecting the thermal regime of the frozen soil at the base of the road, are also considered. In order to stabilize the road structure on permafrost soils, the team of authors of this article proposed 3 structural-technological solutions for the construction of roads, depending on the moisture levels of the upper soil mass, calculated for geotechnical and temperature-humidity conditions typical for the Yamalo-Nenets Autonomous district. The scheme, description and assessment of the effectiveness of each proposed structural-technological solution is given. Efficiency of the assessment is based on a comparison of the numerical modeling results of the water-thermal mode of mound with the proposed structural-technological solutions and ground embankments of roads on permafrost. The results of the numerical modeling of road embankments on permafrost soils are presented. The main conclusions of the research are formulated.

scholarly journals Numerical analysis of the elastic-plastic behavior of a tubular structure in FGM under pressure and defect presence

2021 ◽  
Vol 16 (59) ◽  
pp. 212-231
Author(s):  
Kouider Madani ◽  
A. Houari ◽  
A.S. Bouchikhi ◽  
M. Mokhtari
Keyword(s):  
Equivalent Stress ◽  
Functionally Graded ◽  
Plastic Behavior ◽  
Graded Materials ◽  
Plastic Properties ◽  
Cylindrical Structures ◽  
Elastic Plastic ◽  
The Many ◽  
Von Mises ◽  
Micro Cavity

Given the field of application and the many advantages, the use of FGM (Functionally Graded Materials) materials has recently been extended in several components and more particularly in cylindrical structures, which have been the subject of several recent studies. Our work aims to use the finite element method to analyze a cylindrical structure in FGM with properties gradated in the direction of the radius (Thickness) solicited purely in internal pressure by the implementation of a UMAT subroutine in the calculation code ABAQUS. The elasto-plastic behavior of the FGM is described by the flow theory represented by the equivalent stress of Von Mises and an incremental hardening variable. The TTO model (Tamura-Tomota-Ozawa) was used only to determine the elastic-plastic properties of the FGM material. The radial, tangential and axial stresses according to the thickness were evaluated in the first part of our work. In the second part, these stresses are evaluated under the same conditions but with the presence of a micro-cavity. The results obtained show clearly that these stresses are in direct relation not only with the thickness and properties of the FGM tube but also with the presence of the cavity.

Investigation of the Plastic Properties of Certain Ferrous and Nonferrous Materials at High Temperature

1976 ◽  
Vol 98 (3) ◽  
pp. 203-212 ◽  
Author(s):  
B. Kaftanog˘lu ◽  
K. Sivaci
Keyword(s):  
High Temperature ◽  
Metal Forming ◽  
Empirical Equation ◽  
Plastic Anisotropy ◽  
Equivalent Stress ◽  
Equivalent Strain ◽  
Carbon Steels ◽  
Tension Test ◽  
Plastic Properties ◽  
Anisotropy Parameters

Plastic properties of certain carbon steels, brasses, copper, and aluminum are determined between room and recyrstallization temperatures. The investigations are carried out using the tension test conducted in a specially constructed furnace. Equivalent-stress, equivalent-strain curves and plastic anisotropy parameters are obtained. The equivalent-stress, equivalent-strain curves are then fitted to an empirical equation σ¯ = A(B + ε¯)n by a computer program employing a numerical gradient method. The results show that equivalent stress decreases as the temperature increases, and it increases as the strain-rate increases. Materials obtained as round bars show very little plastic anisotropy in their transverse planes whereas materials in the form of sheets have pronounced anisotropy. Plastic anisotropy decreases as temperature increases. The results obtained and techniques used may prove to be useful for designers of metal forming equipments, and researchers in the area of plasticity.

Study on Interaction between Soil and U-Shaped Subway Tunnel in the Environment of Ground Fissures

2011 ◽  
Vol 250-253 ◽  
pp. 2342-2345 ◽  
Author(s):  
Yang Liu ◽  
Kai Ling Li ◽  
Yu Ming Men ◽  
Guang Yuan Weng ◽  
Hong Jia Liu
Keyword(s):  
Hanging Wall ◽  
Interaction Mechanism ◽  
Vertical Displacement ◽  
Soil Mass ◽  
Relative Displacement ◽  
Tunnel Structure ◽  
Subway Tunnel ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Deformation Area

The interaction mechanism, between soil and U-shaped Subway tunnel, is studied by numerical simulation in the environment of ground fissures. The Subway Line 2 through the ground fissures in Xi’an. The analysis results show that the soil mass influenced by the relative displacement and the vertical displacement gradually increases with the relative displacement increasing of ground fissures movement. The deformation area of tunnel lies in the two sides of presupposed ground fissure, and the area enlarge with vertical relative displacement increasing. The tunnel structure damages at the ground fissures when the relative displacement reaches to 100mm. The footwall part is in tension and the hanging wall part is under pressure on the top of tunnel structure at the ground fissure. The footwall part is under pressure and the hanging wall part is in tension on the bottom of tunnel structure at the ground fissure. In the practical projects, the sectional type tunnel should be employed when the Subway tunnel through the ground fissures.

scholarly journals Numerical Modelling and Multi Objective Optimization Analysis of Heavy Vehicle Chassis

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2028
Author(s):  
Abhishek Agarwal ◽  
Linda Mthembu
Keyword(s):  
Motor Vehicle ◽  
Equivalent Stress ◽  
Optimization Techniques ◽  
Mass Reduction ◽  
Space Filling ◽  
Design Scheme ◽  
Taguchi Design Of Experiments ◽  
Cross Member ◽  
Vehicle Chassis ◽  
Optimal Space

The primary supporting structure of an automobile and its other vital systems is the chassis. The chassis structure is required to bear high shock, stresses, and vibration, and therefore it should possess adequate strength. The objective of current research is to analyze a heavy motor vehicle chassis using numerical and experimental methods. The CAD design and FE analysis is conducted using the ANSYS software. The design of the chassis is then optimized using Taguchi design of Experiments (DOE); the optimization techniques used are the central composite design (CCD) scheme and optimal space filling (OSF) design. Thereafter, sensitivity plots and response surface plots are generated. These plots allow us to determine the critical range of optimized chassis geometry values. The optimization results obtained from the CCD design scheme show that cross member 1 has a higher effect on the equivalent stresses as compared to cross members 2 and 3. The chassis mass reduction obtained from the CCD scheme is approximately 5.3%. The optimization results obtained from the OSF scheme shows that cross member 2 has a higher effect on equivalent stress as compared to cross members 1 and 3. The chassis mass reduction obtained from optimal space filling design scheme is approximately 4.35%.

scholarly journals Pengaruh Beban Kendaraan sebagai Beban Terbagi Rata terhadap Deformasi Geogrid sebagai Perkuatan Embankment

2012 ◽  
Vol 8 (1) ◽  
pp. 31
Author(s):  
Adhe Noor Patria
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Vertical Displacement ◽  
Soil Mass ◽  
Vehicle Load ◽  
Surcharge Load ◽  
The Difference ◽  
High Level

<p>Soft soil such as clay was sensitive soil. Public contructions built in this kind of soil would face some problemssuch as long period consolidation time, unstable embankment slope, not easily compacted and high level settlement. Some solution that could be suggested were the usage of vertical drain, or the usage of geosynthetics material such as geogrid combined with floating  piles.Analysis was carried out by using plaxis version 7.2. soil for embankment and embankment foundation was modelled in plane strain. Also geogrid andfloating piles were modelled in palne strain too. Surcharge load on top of embanknet were variated, they were 20, 35 and 50 kPa. The simulation was carried out in staged contruction mode.Final vertical displacement in geogrid due to 50  kPa vehicle load as surcharge load and long term load period (in this case excess pore water pressure was small) was -0,9062 m for  rigid embankment and -1,4206 for interface embankment. The difference occured due to slip at the interface of geogrid and soil. It  leaded to adding soil mass supportd by geogrid, furthermore the deflection of geogrid became bigger.</p>

scholarly journals Design of a load carriage system oriented to reduce acceleration forces when carrying a backpack

2019 ◽  
pp. 34-43
Author(s):  
Camilo Eduardo Pérez-Cualtán ◽  
Oscar Iván Campo-Salazar
Keyword(s):  
Body Weight ◽  
Energy Expenditure ◽  
Center Of Mass ◽  
Reaction Force ◽  
Vertical Displacement ◽  
The Body ◽  
Load Carriage ◽  
Vertical Ground Reaction Force ◽  
Military Life ◽  
Vertical Ground

In military life, load carriage is an unavoidable part of field operations which is the reason why soldiers often make use of a military backpack. Infantry soldiers usually carry loads weighting more than 30% of their body weight. When the soldier carries a certain weight, his energy expenditure increases, which causes a reduction in performance. The transported load has a movement similar to the vertical displacement of the center of mass of the soldier while walking. This leads to a significant increase in the acceleration forces generated by the action of said load on the body which explains the increase in energy expenditure. The objective of this project was to develop a load carriage system that suspends the load and reduces its vertical displacement. Results show a reduction in both the vertical excursion of the load and in the total vertical ground reaction force when carrying a load with the developed prototype, with respect to the conventional military backpack.

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