A bead laying algorithm for enhancing the stability and dynamic behavior of thin-walled structures

2012 ◽  
Vol 223 (8) ◽  
pp. 1621-1631 ◽  
Author(s):  
C. Bilik ◽  
D. H. Pahr ◽  
F. G. Rammerstorfer
Keyword(s):  
Dynamic Behavior ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
The Stability

Basic Concepts in the Stability Theory of Thin-walled Structures

2010 ◽  
Author(s):  
A. Guran ◽  
L. Lebedev ◽  
Michail D. Todorov ◽  
Christo I. Christov
Keyword(s):  
Stability Theory ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
Basic Concepts ◽  
The Stability

scholarly journals Study of Local and Distortional Stability of Thin-Walled Structures

2018 ◽  
Vol 149 ◽  
pp. 01089
Author(s):  
Mahi Imene ◽  
Djafour Naoual ◽  
Djafour Mustapha
Keyword(s):  
Design Method ◽  
Global Mode ◽  
Thin Walls ◽  
Thin Walled Structures ◽  
Post Buckling ◽  
Steel Sections ◽  
Resistance Curves ◽  
Thin Walled ◽  
The Stability ◽  
Hot Rolled

Thin-walled structures have an increasingly large and growing field of application in the engineering sector, the goal behind using this type of structure is efficiency in terms of resistance and cost, however the stability of its components (the thin walls) remains the first aspect of the behavior, and a primordial factor in the design process. The hot rolled sections are known by a consequent post-buckling reserve, cold-formed steel sections which are thin-walled elements also benefit, in this case, it seems essential to take into account the favorable effects of this reserve in to the verification procedure of the resistance with respect to the three modes of failures of this type of structure. The design method that takes into account this reserve of resistance is inevitably the effective width method. The direct strength method has been developed to improve the speed and efficiency of the design of thin-walled profiles. The latter mainly uses the buckling loads (for Local, Distortional and Global mode) obtained from a numerical analysis and the resistance curves calibrated experimentally to predict the ultimate load of the profile. Among those, the behavior of a set of Cshaped profiles (highly industrialized) is studied, this type of section is assumed to be very prone to modes of local and distortional instability. The outcome of this investigation revealed very relevant conclusions both scientifically and practically.

Experimental Study of the Dynamic Behavior of Thin-Walled Tubular Workpieces in Turning Cutting Process

2020 ◽  
pp. 1-19
Author(s):  
Zied Sahraoui ◽  
Kamel Mehdi ◽  
Moez Ben Jaber
Keyword(s):  
Dynamic Behavior ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Process ◽  
Machining Process ◽  
Structural Damping ◽  
Turning Process ◽  
Manufactured Products ◽  
Thin Walled ◽  
The Stability

Nowadays, industrialists, especially those in the automobile and aeronautical transport fields, seek to lighten the weight of different product components by developing new materials lighter than those usually used or by replacing some massive parts with thin-walled hollow parts. This lightening operation is carried out in order to reduce the energy consumption of the manufactured products while guaranteeing optimal mechanical properties of the components and increasing quality and productivity. To achieve these objectives, some research centers have focused their work on the development and characterization of new light materials and some other centers have focused their work on the analysis and understanding of the encountered problems during the machining operation of thin-walled parts. Indeed, various studies have shown that the machining process of thin-walled parts differs from that of rigid parts. This difference comes from the dynamic behavior of the thin-walled parts which is different from that of the massive parts. Therefore, the purpose of this paper is to first highlight some of these problems through the measurement and analysis of the cutting forces and vibrations of tubular parts with different thicknesses in AU4G1T351 aluminum alloy during the turning process. The experimental results highlight that the dynamic behavior of turning process is governed by large radial deformations of the thin-walled workpieces and the influence of this behavior on the variations of the chip thickness and cutting forces is assumed to be preponderant. The second objective is to provide manufacturers with a practical solution to the encountered vibration problems by improving the structural damping of thin-walled parts by additional damping. It is found that the additional structural damping increases the stability of the cutting process and reduces considerably the vibrations amplitudes.

Experiments on Stability Performance of Thin-Walled, Open-Top Steel Storage Tanks Subjected to Local Support Settlement

2020 ◽  
pp. 2150005
Author(s):  
Hamid Naseri ◽  
Hossein Showkati ◽  
Tadeh Zirakian ◽  
Sina Nasernia
Keyword(s):  
Small Scale ◽  
Storage Tanks ◽  
Practical Applications ◽  
Stability Performance ◽  
Thin Walled Structures ◽  
Scale Models ◽  
Local Support ◽  
Buckling Stability ◽  
Thin Walled ◽  
The Stability

Local support settlement is a typical differential settlement which may take place under steel storage tanks and can adversely affect the stability performance of such thin-walled structures. Considering the practical applications of the thin-walled steel storage tanks in industry, proper treatment of this problem is essential to ensure the high structural performance of such members which albeit requires detailed investigations. On this basis, this study investigates the effects of the local support settlement on the buckling stability of two tanks without and with a top stiffening ring through the experimental and numerical approaches. The considered tanks are small-scale models with the height-to-radius and radius-to-thickness (slenderness) ratios of 1.0 and 834, respectively. Both experimental and numerical results show that the behavior of the tank under the local support settlement is nonlinear. Moreover, the effectiveness of the top stiffening ring in limiting the buckling deformation and improving the buckling performance of the tank is demonstrated in this study.

scholarly journals INFLUENCE OF MATERIAL REMOVAL ON THE DYNAMIC BEHAVIOR OF THIN-WALLED STRUCTURES IN PERIPHERAL MILLING

2006 ◽  
Vol 10 (3) ◽  
pp. 275-287 ◽  
Author(s):  
V. Thevenot ◽  
L. Arnaud ◽  
G. Dessein ◽  
G. Cazenave–Larroche
Keyword(s):  
Dynamic Behavior ◽  
Material Removal ◽  
Peripheral Milling ◽  
Thin Walled Structures ◽  
Thin Walled

scholarly journals INVESTIGATION OF THIN-WALLED COLUMN WITH VARIABLE I-SECTION STABILITY USING FINITE ELEMENT METHOD/PLONASIENĖS KINTAMOJO DVITĖJO SKERSPJŪVIO KOLONOS STABILUMO TYRIMAS BAIGTINIŲ ELEMENTŲ METODU

2000 ◽  
Vol 6 (2) ◽  
pp. 69-75
Author(s):  
Michail Samofalov ◽  
Rimantas Kačianauskas
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stability Analysis ◽  
Numerical Experiments ◽  
Relative Length ◽  
Bending Moment ◽  
Relative Height ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
The Stability

Thin-walled structures are widely used in building construction. Stability analysis [1–10] is of major importance to the design of thin-walled structures. This paper deals with the stability analysis of the thin-walled tapered column [11–18]. The aim is to investigate the influence of variation of the web height on the stability of column and combined action of axial force and plane bending moment. Critical state is defined by stability surface obtained by numerical experiments using the finite element method. Mathematical model of the linearised stability problem is presented as algebraic eigenvalue problem (1), where eigenvalues express the critical loading factor (2). Analytical solutions are known for particular cases of separate loading (4), (5). In this paper, the column with variable I-section is presented as assemblage of beam elements with constant section. Thin-walled beam element has 14 degrees of freedom (Fig 1), including linear displacements, rotations and warping displacements. Variation of cross-section of the column (Fig 2) is defined by relative height of web alb, were a and b are the height at the ends of column. Critical state is described by stability surface obtained using numerical experiments. Stability surface presents in the space of relative variation of height a/b, relative length and relative critical force and bending moment . Variation of section influences the critical bending moment only. The influence of finite element number on the with different relative height of web a/b is investigated numerically (Fig 3), and its variation of stability surface is presented in Fig 4. The numerical results show that variation of critical moment to relative web height a/b is linear (Fig 5). The shapes of buckling modes are presented in Fig 6. Variation of stability surface to relative length (6) is presented in Figs 7 and 8 and expressed by the simple expression (6) constructed on the basis of numerical experiments. Finally, the stability model (1) is compared with nonlinear calculations performed using program ANSYS [19] and shell finite elements (Figs 9 and 10).

Spherical shape stability of shells and cavities

2007 ◽  
Vol 5 ◽  
pp. 38-59 ◽  
Author(s):  
M.A. Ilgamov
Keyword(s):  
Spherical Shape ◽  
Past Century ◽  
Shape Stability ◽  
Thin Walled Structures ◽  
The World ◽  
Thin Walled ◽  
The Stability ◽  
Working Media ◽  
Reliable Methods ◽  
Spherical Shape Stability

Thin-walled shells characteristic of their light weight and strength are used everywhere – in household items to ocean liners and space rockets. Their applications are so diversified and uncountable that one can safely say, ”The world consists of shells; the world rests on shells.” After all, the Earth’s crust is also a shell. The wide application of thin-walled structures has triggered the need for developing reliable methods to calculate their strength and stability, and this is just the research subject of the shell theory, a new branch of mechanics arisen in the past century. The important role is found to be played by their interaction with working media. The present paper discusses the issues on the stability of spherical thin-walled shells and gas cavities in liquid.

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