Flexible bar compression test

2021 ◽  
Author(s):  
A.V. Egorov
Keyword(s):  
Initial Imperfection ◽  
Critical Force ◽  
Theoretical Research ◽  
Design Calculation ◽  
Special Equipment ◽  
Euler Formula ◽  
Initial Shape ◽  
Analysis Methodology ◽  
Steel Bar ◽  
Geometric Boundary

The article considers experimental and theoretical research of longitudinal stability of a flexible steel bar design under axial compression. The bar is a flat thin-walled element, pivotally fixed at the ends. The experimental study was carried out on a Zwick/Roell Z100 installation using special equipment that simulates geometric boundary conditions. During the loading process, a diagram of the deformation of a real bar with initial shape imperfections was automatically constructed. The experimental critical force was determined from the deformation diagram. This force was compared with the critical forces obtained from calculations using two schemes: the Euler formula and the dynamic analysis methodology. In the second scheme, in contrast to the first one, the initial imperfection, established by the measurements of the tested structure, was taken into account. The design calculation errors for both schemes were determined.

scholarly journals Slender metal web stability analysis: Impact of initial imperfection on the mode of buckling

2020 ◽  
Vol 313 ◽  
pp. 00006
Author(s):  
Martin Psotný
Keyword(s):  
Initial Imperfection ◽  
Iteration Algorithm ◽  
Initial Shape ◽  
Aspect Ratios ◽  
Nonlinear Approach ◽  
Linearized Problem ◽  
Nonlinear Equilibrium ◽  
Post Buckling ◽  
Ansys System ◽  
Raphson Iteration

The post buckling of a rectangular slender web in compression has been analyzed. Shapes of a buckling area obtained from the nonlinear analysis have been compared with buckling modes from the linearized problem for various aspect ratios. Effects of initial shape imperfections upon the analysis have been investigated using nonlinear approach. To trace the complete nonlinear equilibrium curves, specialized code based on FEM was created. The Newton-Raphson iteration algorithm was used, load versus displacement control was changed during the process of calculation. Obtained results were verified using Ansys system, in this case arc-length method was activated for overcoming critical points.

Buckling Delamination of a Rectangular Sandwich Thick Plate With Band Cracks

2010 ◽  
Author(s):  
Surkay Akbarov ◽  
Nazmiye Yahnioglu ◽  
Ayfer Tekin
Keyword(s):  
Thick Plate ◽  
Compressive Loading ◽  
Three Dimensional ◽  
Initial Imperfection ◽  
Core Layer ◽  
Solution Procedure ◽  
Critical Force ◽  
Geometrical Parameters ◽  
Field Equations ◽  
Buckling Delamination

The buckling delamination around the band cracks contained with the simply supported all edge-surface rectangular sandwich thick plate is investigated. It is assumed that the sandwich plate is composed of two face layers and a core layer. Face and core layers are made of different materials and it is assumed that there are two same cracks at the interfaces between the layers. Material of each layer is isotropic and homogeneous. For the solution procedure it is supposed that the surfaces of the cracks have insignificant initial imperfections. The development of this initial imperfection with an external compressive loading acting along the cracks is studied in the framework of the three dimensional geometrically nonlinear field equations of the elasticity theory and the piece-wise homogeneous body model. For the determination of the values of the critical force the initial imperfection criterion i.e. the case where the imperfection starts to increase and grows indefinitely, is used. The corresponding boundary value problems are solved by employing the boundary form perturbation techniques and the three dimensional FEM. The numerical results on the critical force are presented and analyzed. The influences of the material and geometrical parameters on these critical values are discussed.

scholarly journals Application of Support Vector Machine in Fault Diagnosis of Elevator Key Structures

2019 ◽  
Vol 267 ◽  
pp. 01008
Author(s):  
Yan Dou ◽  
Lanzhong Guo ◽  
Yunbo Li ◽  
Yunfei Zhu
Keyword(s):  
Support Vector Machine ◽  
Fault Diagnosis ◽  
Engineering Application ◽  
Life Safety ◽  
Theoretical Research ◽  
Support Vector ◽  
Special Equipment ◽  
Accurate Identification

Elevator is an important equipment in special equipment, its operation reliability is related to the life safety of elevator passengers; when the elevator fails, how to timely accurate identification of fault types and judgment of fault causes are the key to engineering application and theoretical research. This paper mainly introduces the application of support vector machine in fault diagnosis of elevator key structures.

Buckling Delamination of the Rectangular Orthotropic Thick Plate With an Edge Rectangular Crack

2010 ◽  
Author(s):  
Surkay Akbarov ◽  
Nazmiye Yahnioglu ◽  
Esra Eylem Karatas
Keyword(s):  
Compressive Loading ◽  
Three Dimensional ◽  
Initial Imperfection ◽  
Critical Force ◽  
Geometrical Parameters ◽  
Field Equations ◽  
Rectangular Crack ◽  
Anisotropic Bodies ◽  
Buckling Delamination

The buckling delamination problem for the rectangular plate made from composite (orthotropic) material is studied. It is supposed that the plate has a rectangular edge-crack and edge-surfaces of that have an initial infinitesimal imperfection. The development of this initial imperfection with an external compressive loading acting along the crack is studied in the framework of the three-dimensional geometrically nonlinear field equations of the elasticity theory of anisotropic bodies. For the determination of the values of the critical force the initial imperfection criterion is used. The corresponding boundary-value problems are solved by employing the boundary form perturbation techniques and the FEM. The influence of the material or geometrical parameters of the plate on the values of critical force is discussed.

The Design & Calculation for Hydraulic Cylinder of a Special Machine for Heat Exchanger Tube Bundle Drawing and Assembling

2014 ◽  
Vol 496-500 ◽  
pp. 789-792
Author(s):  
Ke Yang ◽  
Shang Jun Guan ◽  
Xiang Dong Wang
Keyword(s):  
Heat Exchanger ◽  
Tube Bundle ◽  
Hydraulic Cylinder ◽  
Design Calculation ◽  
Heat Exchanger Tube ◽  
Special Equipment ◽  
Special Machine ◽  
Safety And Reliability ◽  
Petroleum Chemical ◽  
Exchanger Tube

Heat exchanger tube bundle drawing and assembling machine is special equipment for maintenance of heat exchanger of petroleum, chemical and other enterprises, specifically for removal and installation of the heat exchanger tube bundle. This paper introduces a self-developed heat exchanger tube bundle drawing and assembling machine’s overall structure, driving principle, hydraulic system and the design of hydraulic cylinder, which has ensured the safety and reliability of a Special machine for Heat exchanger tube bundle drawing and assembling.

scholarly journals Numerical Analysis Of Buckling Of Von Mises Planar Truss

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
Martin Kalina
Keyword(s):  
Discrete Model ◽  
Computational Algorithm ◽  
Vertical Displacement ◽  
Critical Force ◽  
Initial Shape ◽  
Geometric Imperfection ◽  
Structure Deformation ◽  
Asymmetric Effects ◽  
Steel Truss ◽  
Von Mises

Abstract A computational algorithm of a discrete model of von Mises planar steel truss is presented. The structure deformation is evaluated by seeking the minimal potential energy. The critical force invented by mathematical solution was compared with solution by computer algorithm. Symmetric and asymmetric effects of initial shape of geometric imperfection of axis of struts are used in model. The shapes of buckling of von Mises planar truss of selected vertical displacement of top joint are shown.

Tensile Failure of 55-Nitinol Wire

1975 ◽  
Vol 33 ◽  
pp. 46-47
Author(s):  
F. I. Grace
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Stoichiometric Composition ◽  
Tensile Failure ◽  
Initial State ◽  
Initial Shape ◽  
Nitinol Wire ◽  
Cscl Type ◽  
Shear Transformation

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.

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