Technical Buckling, Stress and Strain Simplified Analysis of Semi-Slender Thin-Walled Cylindrical Pinned Column

Circular thin-walled elastic tubes under concentric axial loading usually fail by shell buckling, and in practical design procedures the buckling load can be determined by modifying the local buckling stress to account empirically for the imperfection sensitive response that is typical in Donnell shell theory. While the local buckling stress of a hollow thin-walled tube under concentric axial compression has a solution in closed form, that of a thin-walled circular tube with an elastic infill, which restrains the local buckling mode, has received far less attention. This paper addresses the local buckling of a tubular member subjected to axial compression, and formulates an energy-based technique for determining the local buckling stress as a function of the stiffness of the elastic infill by recourse to a transcendental equation. This simple energy formulation, with one degree of buckling freedom, shows that the elastic local buckling stress increases from 1 to [Formula: see text] times that of a hollow tube as the stiffness of the elastic infill increases from zero to infinity; the latter case being typical of that of a concrete-filled steel tube. The energy formulation is then recast into a multi-degree of freedom matrix stiffness format, in which the function for the buckling mode is a Fourier representation satisfying, a priori, the necessary kinematic condition that the buckling deformation vanishes at the point where it enters the elastic medium. The solution is shown to converge rapidly, and demonstrates that the simple transcendental formulation provides a sufficiently accurate representation of the buckling problem.

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A FEA Method for Mathematical Calculation and Prediction Analysis Cross-sectional Ovalization of Tubes under Rotary Straightening

Journal of Physics Conference Series ◽

10.1088/1742-6596/2083/4/042057 ◽

2021 ◽

Vol 2083 (4) ◽

pp. 042057

Author(s):

Ziqian Zhang ◽

Ying Zhong

Keyword(s):

Process Parameters ◽

Element Model ◽

Simulation Method ◽

Stress And Strain ◽

Cross Sectional ◽

Bending Deformation ◽

Deformation Stage ◽

Thin Walled Pipe ◽

Thin Walled ◽

Flattening Process

Abstract The section flattening phenomenon (namely Bazier effect) will occur in the large bending deformation stage of thin-walled pipe in the continuous straightening process. The maximum section flattening amount and the residual section flattening amount are important process parameters, which are the basis for calculating the subsequent process parameters of the flattening circle, and directly determine the roundness of the final pipe and the product quality. However, it is hard to be obtained by the theoretical or experimental methods. Therefore, based on the structure and process parameters of the leveler, a finite element model was built to simulate the section flattening process. Then, ANSYS/LS-DYNA software was used to dynamically simulate the bending flattening phenomenon of thin-walled pipe in the continuous straightening process, and the stress and strain nephographic of the flattening deformation zone was obtained. By recording the position curve of the key nodes in the preventing process, the section flattening amount of the thin-walled pipe in the large bending deformation stage in the continuous straightening process was determined. The simulation results show that the dynamic simulation method can effectively predict the section flattening of thin-walled pipe in the process of continuous straightening.

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Stress and Strain Definition of an Open Profile Thin-Walled Beam at Constrained Torsion by Boundary Element Method

Journal of Theoretical and Applied Mechanics ◽

10.2478/v10254-012-0007-y ◽

2012 ◽

Vol 42 (2) ◽

pp. 43-54

Author(s):

Zlatko Zlatanov

Keyword(s):

Boundary Element Method ◽

Boundary Element ◽

Stress And Strain ◽

One Dimensional ◽

Open Profile ◽

Linear Algebraic Equations ◽

Thin Walled ◽

Definition Of ◽

Constrained Torsion ◽

Element Method

Stress and Strain Definition of an Open Profile Thin-Walled Beam at Constrained Torsion by Boundary Element Method Thin-walled beams with open profile at constrained torsion are investigated in this paper. A thin-walled beam loaded by an external bi-moment at constrained torsion is investigated in this paper. An analytical variant of the boundary element method (BEM) is presented, which is based on a new scheme of the integral ratios transformation of the initial parameters method in a system of linear algebraic equations. Only one dimensional integrals are used defining the one dimensional continuum.

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Methods, Models, and Assumptions Used in Finite Element Simulation of a Pilger Metal Forming Process

Computer Technology and Applications ◽

10.1115/pvp2003-1895 ◽

2003 ◽

Author(s):

John Martin

Keyword(s):

Finite Element ◽

Process Parameters ◽

Manufacturing Process ◽

Defect Formation ◽

Process Parameter ◽

Stress And Strain ◽

Finite Element Software ◽

Sensitivity Studies ◽

Modelling Techniques ◽

Thin Walled

The pilger process is a cold-worked mechanical process that combines the elements of extrusion, rolling, and upsetting for the formation of thin-walled tubes. This complex manufacturing process relies on the results of trial and error testing programs, experimental parameter sensitivity studies, and prototypical applications to advance the technology. This finite element modelling effort describes the methods, models, and assumptions used to assess the process parameters used to manufacture thin-walled tubing. The modelling technique breaks down the manufacturing process into smaller computer generated models representing fundamental process functions. Each of these models is linked with the overall process simulation. Simplified assumptions are identified and supporting justifications provided. This work represents proof of principle modelling techniques, using large deformation, large strain, finite element software. These modelling techniques can be extended to more extensive parameter studies evaluating the effects of pilger process parameter changes on final tube stress and strain states and their relationship to defect formation/propagation. Sensitivity studies on input variables and the process parameters associated with one pass of the pilger process are also included. The modelling techniques have been extended to parameter studies evaluating the effects of pilger process parameter changes on tube stress and strain states and their relationship to defect formation. Eventually a complex qualified 3-D model will provide more accurate results for process evaluation purposes. However, the trends and results reported are judged adequate for examining process trends and parameter variability.

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Elastic Critical Buckling Modes and Stress of Cold-Formed Thin-Walled Lipped Channel with Multiple Intermediate Stiffeners

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.501-504.470 ◽

2014 ◽

Vol 501-504 ◽

pp. 470-473

Author(s):

Guang Yue Ma

Keyword(s):

Theoretical Analysis ◽

Experimental Results ◽

Elastic Buckling ◽

Channel Member ◽

Buckling Modes ◽

Important Thing ◽

Buckling Stress ◽

Thin Walled

Elastic buckling modes of cold-formed thin-walled steel member have three relevant types: local, distortional and global. The complicated and important thing is to differentiating buckling modes and resolving buckling stress for engineers. It will be given for Cold-formed thin-walled lipped channel member with multiple intermediate stiffeners. The theoretical analysis coincide exactly with the experimental results, it can be used as a reference for engineers.

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Simplified Analysis of Thin-Walled Composite Members

Journal of Structural Engineering ◽

10.1061/(asce)0733-9445(1996)122:11(1379) ◽

1996 ◽

Vol 122 (11) ◽

pp. 1379-1383 ◽

Cited By ~ 5

Author(s):

A. Ghorbanpoor ◽

B. Omidvar

Keyword(s):

Simplified Analysis ◽

Thin Walled

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STUDY OF STRESS AND STRAIN STATES OF REINFORCEMENT IN RUBBER-METAL PRODUCTS DURING THEIR MANUFACTURE

Journal of Rocket-Space Technology ◽

10.15421/451911 ◽

2019 ◽

Vol 27 (4) ◽

pp. 67-73

Author(s):

Mikhail Stepanovich Khorolskyi ◽

Anatoliy Fedorovich Sanin

Keyword(s):

Equilibrium State ◽

Strain State ◽

New Technologies ◽

Stress And Strain ◽

Reinforcing Steel ◽

Standard Samples ◽

Molding Process ◽

Metal Bonding ◽

Metal Products ◽

Thin Walled

Stress and strain states are typical for rubber-to-metal bonding areas in the rubber-metal products developed specifically for the space industry, particularly those with thin-walled reinforcement, i.e. dampers and brackets. To achieve maximum rubber adhesion to metal, 80-120 µm shot or aluminum oxide blasting at the air pressure of 0.6-0.8 MPa is applied to the reinforcing steel of straight or any other shape. The blasting process causes an improvement in the hardness of the material by strain hardening, which results in the backward deformation of the reinforcement. After the blasting process, the reinforcing steel changes its geometry and stress and strain state. A new equilibrium state appears. Rubber-metal products are typically cast under pressure using press molds by vulcanizing a rubber mix at high temperatures. Bonding rubber to metal using an adhesive takes place simultaneously. During the molding process, the deformed reinforcement returns to its original shape once the pressure is applied and preserves its shape for some time due to strong rubber-to-metal bonds. Yet, after the rubber-metal product is taken out of the mold, the stress and strain state emerges in the rubber-to-metal bonding area, as the reinforcing steel wants to return to its equilibrium state. With the relaxation developing as time passes, delamination of the rubber-to-metal system occurs and the product can no longer be used. As a result of our research, we determined the relationship between the strength of the rubber-to-metal adhesion and the deformation using standard samples and proposed the methods of the stress and strain state simulation that can be used for development of new technologies enabling manufacturing of rubber-metal products with no or small stress and strain levels. The paper outlines the key approaches to relieving the stress and strain states in the rubber-metal products with thin-walled reinforcement. Using the standard samples, we proved that relieving of the stress and strain state will ensure product operability during the entire period of warranty.

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Elastic Distortional Buckling Stress of Steel Channel Column

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.405-408.644 ◽

2013 ◽

Vol 405-408 ◽

pp. 644-647

Author(s):

Chun Gang Wang ◽

Nai Wen Zhang ◽

Ping Ma

Keyword(s):

Compressive Load ◽

Distortional Buckling ◽

Finite Strip ◽

Axial Compressive Load ◽

Buckling Stress ◽

Web Stiffeners ◽

Thin Walled ◽

The Web

In order to investigate the simple calculative method of channels with complex edge stiffeners for the elastic distortional buckling stress under axial compressive load, a total of 90 cold-formed thin-walled steel channels with Σstyle web stiffeners and complex edge stiffeners , channels with complex edge stiffeners and intermediate V type stiffeners in the web were analyzed by finite strip software CUFSM. The influence of the parameters for the elastic distortional buckling stress was analyzed. Simplified formulas for calculating the elastic distortional buckling stress of Σstyle channels with complex edge stiffeners, channels with complex edge stiffeners and intermediate V type stiffeners in the web under axial compressive load were provided. The availability of the formulas was verified.

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Crushing of circular steel tubes filled with nanoporous-materials-functionalized liquid

International Journal of Damage Mechanics ◽

10.1177/1056789516683539 ◽

2016 ◽

Vol 27 (3) ◽

pp. 439-450 ◽

Cited By ~ 4

Author(s):

Yueting Sun ◽

Yibing Li ◽

Cang Zhao ◽

Meng Wang ◽

Weiyi Lu ◽

...

Keyword(s):

Energy Absorption ◽

Tube Wall ◽

General Rule ◽

Nanoporous Materials ◽

Steel Tubes ◽

Buckling Mode ◽

Buckling Stress ◽

Infiltration Pressure ◽

Load Carrying ◽

Thin Walled

The crush behaviors of steel tubes filled with nanoporous-materials-functionalized liquids are experimentally investigated under quasi-static and dynamic conditions. Results show that the nanoporous-materials-functionalized liquid can enhance the load-carrying and the energy absorption capacities of thin-walled tubes, as the buckling mode is affected. The effective buckling stress increases with the infiltration pressure, and the overall compressibility is highly dependent on the nanopore volume. A general rule of designing nanoporous-materials-functionalized liquid-filled tubes is proposed. The interaction between the tube wall and the nanoporous-materials-functionalized liquid is analyzed.

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