Cylindrical pillar instability beyond elasticity limit

2021 ◽  
pp. 101-113
Author(s):  
A.I. Chanyshev ◽  
I.M. Abdulin ◽  
O.E. Belousova
Keyword(s):  
Elasticity Limit

The limit state of concrete and reinforced concrete rods at complex and longitudinal-transverse bending

2020 ◽  
pp. 60-73
Author(s):  
Yu V Nemirovskii ◽  
S V Tikhonov
Keyword(s):  
General Solution ◽  
Least Squares ◽  
Nonlinear Differential Equations ◽  
Limit State ◽  
Algebraic Equations ◽  
Method Of Least Squares ◽  
Elasticity Limit ◽  
Limit Values ◽  
Symbolic Calculations ◽  
Deformation Diagrams

The work considers rods with a constant cross-section. The deformation law of each layer of the rod is adopted as an approximation by a polynomial of the second order. The method of determining the coefficients of the indicated polynomial and the limit deformations under compression and tension of the material of each layer is described with the presence of three traditional characteristics: modulus of elasticity, limit stresses at compression and tension. On the basis of deformation diagrams of the concrete grades B10, B30, B50 under tension and compression, these coefficients are determined by the method of least squares. The deformation diagrams of these concrete grades are compared on the basis of the approximations obtained by the limit values and the method of least squares, and it is found that these diagrams approximate quite well the real deformation diagrams at deformations close to the limit. The main problem in this work is to determine if the rod is able withstand the applied loads, before intensive cracking processes in concrete. So as a criterion of the conditional limit state this work adopts the maximum permissible deformation value under tension or compression corresponding to the points of transition to a falling branch on the deformation diagram level in one or more layers of the rod. The Kirchhoff-Lyav classical kinematic hypotheses are assumed to be valid for the rod deformation. The cases of statically determinable and statically indeterminable problems of bend of the rod are considered. It is shown that in the case of statically determinable loadings, the general solution of the problem comes to solving a system of three nonlinear algebraic equations which roots can be obtained with the necessary accuracy using the well-developed methods of computational mathematics. The general solution of the problem for statically indeterminable problems is reduced to obtaining a solution to a system of three nonlinear differential equations for three functions - deformation and curvatures. The Bubnov-Galerkin method is used to approximate the solution of this equation on the segment along the length of the rod, and specific examples of its application to the Maple system of symbolic calculations are considered.

scholarly journals Design Go-Kart Chassis Four Strokes 110 Engine

2021 ◽  
Vol 2 (1) ◽  
pp. 17-20
Author(s):  
Misbachuddin
Keyword(s):  
Tensile Testing ◽  
Testing Machine ◽  
Computer Application ◽  
Test Results ◽  
Welding Wire ◽  
Tensile Testing Machine ◽  
Elasticity Limit ◽  
Steel Pipes ◽  
Auto Cad ◽  
A Current

 This study aimed to decide how to design a kart chassis and the strength of the welded joints. In this design, the chassis frame is made of tubular profile steel, which is designed to withstand most of the loads in a vehicle. The chassis was designed using a computer application, namely Auto CAD 2007. Assembly using carbon steel pipes connected using SMAW welding with E6013 RB 2.6 mm welding wire with a current of 75 A, 1G place. The test is carried out with a tensile testing machine. The material is pulled past the most stretch elasticity limit until finally, the specimen reaches the limit (breaks). The tensile test takes about 3-5 minutes with a load of 10-20N. The test results show the average tensile strength of the iron pipe is 0.512 Mpa.

Atomistic Simulation Study of Mechanical Deformation of Al-Mg-Si Alloys

2021 ◽  
Vol 52 ◽  
pp. 149-163
Author(s):  
Hanae Chabba ◽  
Driss Dafir
Keyword(s):  
Deformation Behaviour ◽  
Compressive Loading ◽  
Embedded Atom Method ◽  
Stress Strain ◽  
Elasticity Limit ◽  
Embedded Atom ◽  
High Elasticity ◽  
Strain Relationship ◽  
Atomic Simulations ◽  
Strain Responses

Aluminum alloys have been attracting significant attention. Especially Al-Mg-Si alloys can exhibit an excellent balance between strength and ductility. Deformation mechanisms and microstructural evolution are still challenging issues. Accordingly, to describe how the type of phase influence mechanical behaviour of Al/Mg/Si alloys, in this paper atomic simulations are performed to investigate the uniaxial compressive behaviour of Al-Mg-Si ternary phases. The compression is at the same strain rate (3.1010 s−1); using Modified Embedded Atom Method (MEAM) potential to model the deformation behaviour. From these simulations, we get the total radial distribution function; the stress-strain responses to describe the elastic and plastic behaviors of GP-AlMg4Si6, U2-Al4Mg4Si4 and β-Al3Mg2Si6 phases. For a Detailed description of which phase influence hardness and ductility of these alloys; the mechanical properties are determined and presented. These stress-strain curves obtained show a rapid increase in stress up to a maximum followed by a gradual drop when the specimen fails by ductile fracture. From the results, it was found that GP-AlMg4Si6 & U2-Al4Mg4Si4 phases are brittle under uniaxial compressive loading while β-Al3Mg2Si6 phase is very ductile under the same compressive loading. The engineering stress-strain relationship suggests that β-Al3Mg2Si6 phase have high elasticity limit, ability to resist deformation and have the advantage of being highly malleable. Molecular dynamics software LAMMPS was used to simulate and build the Al-Mg-Si ternary system.

scholarly journals Epicycle method for elasticity limit calculations

2017 ◽  
Vol 95 (14) ◽  
Author(s):  
Axel van de Walle ◽  
Sara Kadkhodaei ◽  
Ruoshi Sun ◽  
Qi-Jun Hong
Keyword(s):  
Elasticity Limit

scholarly journals SIMULATION OF THE MECHANICAL STIMULATION EFFECT ON THE PEN JUNCTION BETWEEN BONE AND PELVIC BASED ON FINITE ELEMENT METHODS

2020 ◽  
Vol 12 (2) ◽  
pp. 65-70
Author(s):  
Khusnul - Yakin
Keyword(s):  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Mechanical Stimuli ◽  
Femoral Bone ◽  
Elasticity Limit ◽  
Left Femur ◽  
Titanium Screw ◽  
Bone Screw ◽  
Trabecular Bones ◽  
The Right

Bone remodeling process influenced by cells osteoblast and osteoclast. The remodeling of cortical and trabecular influenced by mechanical stimuli. In this study, cortical and trabecular bones of 25 years old humans were observed, and the result was the cortical bone has the average Young’s modulo 17.9 MPa with the Poisson’s ratio of 0.4. Trabecular bone has the average Young’s modulo of 13 MPa and the Poisson’s ratio of 0.5. The metal orthopedic bone screw, which has used in this research simulation, was is a Titanium screw. The screw has Young’s modulo of 110 GPa and the Poisson’s ratio of 0.29. The results of the simulation of femoral bone elasticity limit with standing activity at the age of 25 were found in the left femur of 112.9416 MPa and the right femur of 115.5134 MPa. The limit of elasticity of the femur due to walking was found in the left femur of 115.2166 MPa with an accuracy of 94.11% and the right femur of 117.6692 MPa.

scholarly journals Hydraulic fracture in the nonlinear stress field

2020 ◽  
pp. 12-20
Author(s):  
Mirenkov Valerii
Keyword(s):  
Stress Field ◽  
Damage Zone ◽  
Reference Sample ◽  
Elastic Plane ◽  
Computational Domain ◽  
Elasticity Limit ◽  
Initial Stress Field ◽  
Dynamic Framework ◽  
Nonlinear Stress ◽  
The Moment

Introduction. The article considers a variant of a straight finite fracture modeled by a mathematical cut in the elastic plane. Aim. The new model proposed differs from the existing models by the damage zone bounded by the elastic material at the fracture tip up to the moment of the fracture growth. The process of fracturing is essentially nonlinear. Methodology. The model is based on the full-scale tension experiments with a reference sample of rocks enclosing a fracture and having the characteristic stress points, namely, proportionality limit, elasticity limit, plasticity domain and the domain in the vicinity of destructive stresses. Results. The problem with fracture is considered as an experiment to determine deformation with growing pressure in the fracture. The problem has no correct analytical solution. The problem on hydrofracture 20 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 4. 2020 ISSN 0536-1028 assumes the presence of the initial stress field in rock mass, which is essentially used in formulation of boundary conditions. Conclusions. All such problems belong to the class of Cauchy’s problems with an infinitely distant point in the computational domain. This article proposes the correct formulation of the fracture theory problem in the static, kinematic and dynamic framework.

scholarly journals Liquid Metal Antennas: Materials, Fabrication and Applications

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 177 ◽  
Author(s):  
Kashif Nisar Paracha ◽  
Arslan Dawood Butt ◽  
Ali S. Alghamdi ◽  
Suleiman Aliyu Babale ◽  
Ping Jack Soh
Keyword(s):  
Liquid Metal ◽  
High Frequency ◽  
State Of The Art ◽  
Communication Technologies ◽  
Flow Property ◽  
Elasticity Limit ◽  
Capillary Action ◽  
Communication Device ◽  
Flexible Antennas ◽  
Traditional Approaches

This work reviews design aspects of liquid metal antennas and their corresponding applications. In the age of modern wireless communication technologies, adaptability and versatility have become highly attractive features of any communication device. Compared to traditional conductors like copper, the flow property and lack of elasticity limit of conductive fluids, makes them an ideal alternative for applications demanding mechanically flexible antennas. These fluidic properties also allow innovative antenna fabrication techniques like 3D printing, injecting, or spraying the conductive fluid on rigid/flexible substrates. Such fluids can also be easily manipulated to implement reconfigurability in liquid antennas using methods like micro pumping or electrochemically controlled capillary action as compared to traditional approaches like high-frequency switching. In this work, we discuss attributes of widely used conductive fluids, their novel patterning/fabrication techniques, and their corresponding state-of-the-art applications.

scholarly journals Modeling of the interaction of the layered barrier with a high-speed fragment

2019 ◽  
Vol 221 ◽  
pp. 01042
Author(s):  
Alexandr Ishchenko ◽  
Nikolay Belov ◽  
Viktor Burkin ◽  
Anton Sammel ◽  
Nikolay Yugov ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Software Systems ◽  
Fracture Mechanisms ◽  
Elasticity Limit ◽  
Transparent Armor ◽  
Initial Stage ◽  
Numerical Research ◽  
Shock Wave Pressure ◽  
The Impact

For the manufacture of transparent armor of high class protection, as a rule, reinforced silicate glasses, as well as transparent ceramics, are used. Since these materials are resiliently brittle, they can be used only in transparent multilayered barriers with protective back films for protection against high-speed fragmentation elements and bullets. Plexiglass or polycarbonate is most often used as the back layer. The barrier’s face layer must have a hardness substantially higher than the hardness of the drummer’s material, and the Hugonievskii elasticity limit must exceed the shock-wave pressure arising at the initial stage in the barrier. The purpose of this paper is to develop a mathematical model that allows, within the framework of a porous elastic-plastic medium with regard to various fracture mechanisms, to calculate the impact interaction of fragmentation elements with transparent armor. Numerical research was conducted with the help of copyright software systems. Experimental studies of the collision of transparent armor with a splinter simulator in the speed range of 1500 ... 2500 m / s were carried out with the use of throwing installations of the NRI AMM TSU.

Sign in / Sign up

Export Citation Format

Share Document