scholarly journals Study on the Axial Compression Postbuckling Similitude Model of the Stiffened Cylindrical Shell with Dimple Imperfections

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Jiawei Ding ◽  
Xinkui Xing ◽  
Wei Yu ◽  
Wanxu Zhu
Keyword(s):  
Cylindrical Shell ◽  
Axial Compression ◽  
Energy Method ◽  
Test Site ◽  
The Body ◽  
Scale Model ◽  
Nonlinear Buckling ◽  
Stiffened Cylindrical Shell ◽  
New Type ◽  
Scaling Principle

The body of the new-type dry gas holder is a large stiffened cylindrical shell. Limited by the test site and economic conditions, the buckling characteristics of such holders are generally studied through scale model experiments. Taking the longitudinal-ring rectangular stiffened cylindrical shell as the research object, the generalized similitude condition and scaling principle formula of the structure are derived innovatively based on Donnell’s assumption and the energy method. By means of displacement loading and node coordinates updating, dimple imperfections are introduced into the ideal structure of the stiffened cylindrical shell, and then, the complete similitude and partial similitude analysis of axial compression nonlinear buckling for imperfect structures are carried out. The analysis results show that the complete similitude analysis of stiffened cylindrical shell axial-compression nonlinear buckling can be realized accurately; the partial similitude model for stiffened cylindrical shell axial-compression nonlinear buckling can better predict the buckling characteristics of its prototype structures, and the closer the Poisson’s ratio between the model and the prototype materials is, the more accurate the prediction results are. Meanwhile, the generalized similitude condition and scaling principle formula derived based on the energy method can provide useful reference for the model design and experimental verification of the axial compression buckling of the stiffened cylindrical shell with local geometric imperfections.

Buckling of Semimonocoque Structures Under Compression

1942 ◽  
Vol 9 (3) ◽  
pp. A117-A121
Author(s):  
Tsun Kuei Wang
Keyword(s):  
Cylindrical Shell ◽  
Axial Compression ◽  
Cross Section ◽  
Compressive Load ◽  
Circular Cross Section ◽  
Critical Value ◽  
Cylindrical Structure ◽  
Stiffened Cylindrical Shell ◽  
Thin Tube ◽  
Longitudinal Stiffeners

Abstract This paper presents an investigation of the strength of a stiffened cylindrical shell under the action of uniform axial compression. It is assumed that the cylindrical structure is a very thin tube of circular cross section; its reinforcements consist essentially of a great number of uniform longitudinal stiffeners and a great number of uniform transverse rings. It is often desirable to know the critical value of the compressive load for the buckling of such a structure.

Determining Critical States of Equilibrium of Plates and Shells Under Initial Stress

1942 ◽  
Vol 9 (1) ◽  
pp. A27-A30
Author(s):  
H. Hencky
Keyword(s):  
Cylindrical Shell ◽  
Energy Method ◽  
Virtual Work ◽  
The Body ◽  
Principle Of Virtual Work ◽  
Practical Applications ◽  
Fundamental Knowledge ◽  
Plates And Shells ◽  
The Stability

Abstract The purpose of this paper is to show that Rayleigh’s energy method, used by Timoshenko for the determination of critical loads in plates and shells, is capable of an important generalization. The work involved is a direct continuation of the energy method of Timoshenko and is based on the principle of virtual work. According to this principle the variation of the work of the outer forces together with the variation of the kinetic energy is equal to the variation of the elastic energy stored up in the body. The author develops a series of formulas, by means of which the stability of a cylindrical shell under various conditions of stress may be determined. The practical applications of these formulas, requiring only a fundamental knowledge of the mathematics of engineering, are illustrated by suitable examples.

Kropparnas poesi

2021 ◽  
Vol 51 (1-2) ◽  
pp. 5-14
Author(s):  
Anna-Klara Bojö
Keyword(s):  
Women Writers ◽  
Young Women ◽  
Literary History ◽  
The Body ◽  
Different Types ◽  
New Type

The Bodies’ Poetry: Eva Runefelt, Eva Ström and Swedish Poetry in the Late 1970’s In the mid 1970’s a new type of poetry, associated with the body, emerged in Sweden. Especially young women writers appeared to take Swedish poetry in new aesthetic directions, exploring questions regarding experience and language. This article focuses on two prominent writers, Eva Runefelt and Eva Ström, and discusses how their different types of poetry can be said to be a bodies’ poetry, and how it was discussed in contemporary literary critique. It also reflects on why this strand of poetry has been granted such a peripheral place in literary history.

Enhanced surface hydrophilicity of polylactic acid sutures treated by lipase and chitosan

2018 ◽  
Vol 89 (16) ◽  
pp. 3291-3302 ◽  
Author(s):  
Shuqiang Liu ◽  
Mingfang Liu ◽  
Gaihong Wu ◽  
Xiaofang Zhang ◽  
Juanjuan Yu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Friction Coefficient ◽  
Surface Area ◽  
Polylactic Acid ◽  
The Body ◽  
Optimal Conditions ◽  
Absorbable Sutures ◽  
Surgical Sutures ◽  
New Type ◽  
Enhanced Surface

Polylactic acid (PLA) surgical sutures are a new type of absorbable sutures that can be degraded and absorbed in the body. However, there is high hydrophobicity for the surface of PLA sutures, which leads to poor biocompatibility and cellular affinity. In order to increase the hydrophilicity, the PLA sutures were etched by lipase firstly, and then grafted with chitosan. The results indicate that the optimal conditions of treating PLA sutures by lipase were as follows: 45℃ reaction temperature, 4.5 g/L concentration of lipase and 8 h reaction time. The sutures were etched by lipase and then formed some grooves and a number of hydroxyl (-OH) bonds, which led to increased surface area and hydrophilicity, but a drop in mass and strength. The optimal conditions of grafting chitosan onto PLA sutures were as follows: 4 h reaction time and 3 g/L concentration of chitosan. The chitosan grafted and loaded on the surface of PLA sutures, and in some areas of the sutures the chitosan reunited, which led to a rough surface and large friction coefficient. Finally, the hydrophilicity of the PLA sutures, treated by lipase and then grafted with chitosan, was greatly improved.

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