scholarly journals Analysis of wrinkled membrane structures based on a wrinkle-wave model

AIP Advances ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 015301 ◽  
Author(s):  
Mingjun Liu ◽  
Jin Huang ◽  
Yali Wang
Keyword(s):  
Wave Model ◽  
Membrane Structures ◽  
Wrinkled Membrane

scholarly journals A Finite Element Model for the Analysis of Wrinkled Membrane Structures

2003 ◽  
Vol 18 (1) ◽  
pp. 1-14 ◽  
Author(s):  
René Ziegler ◽  
Werner Wagner ◽  
Kai-Uwe Bletzinger
Keyword(s):  
Finite Element ◽  
Quadratic Convergence ◽  
Element Model ◽  
Significant Progress ◽  
Membrane Structures ◽  
Wrinkling Analysis ◽  
Convergence Behaviour ◽  
Consistent Linearization ◽  
Wrinkled Membrane ◽  
Tension Field Theory

The problem of wrinkling in membrane structures has been a field of research since the publication of the tension field theory for plane structures. Significant progress in wrinkling analysis of arbitrarily shaped membranes has been made with the development of numerical methods. In the paper we present the enhancements of a standard finite element membrane formulation which allow to depict the wrinkles within the plane of the structure. A mathematical-numerical method is derived, which describes a valid stress state by minimising the differences in the stress density function while observing the wrinkling conditions. A consistent linearization of the proposed algorithms ensures quadratic convergence behaviour.

Numerical Analysis of Wind-Induced Response of a Wrinkled Membrane

2020 ◽  
Vol 20 (05) ◽  
pp. 2050056
Author(s):  
Xiaofeng Wang ◽  
Haoyue Chu ◽  
Qingshan Yang
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Wind Tunnel Test ◽  
Dynamic Responses ◽  
Wind Loads ◽  
Induced Response ◽  
Induced Responses ◽  
Membrane Structures ◽  
Wind Speeds ◽  
Wrinkled Membrane

Membranes have been popularly used in the fields of civil engineering and aerospace engineering. When wrinkled, a membrane loses its stiffness in the direction perpendicular to wrinkles and is more sensitive to wind loads. This paper numerically studied the wind-induced responses of a wrinkled membrane and their variations with respect to wind speed, wind direction and wrinkling deformation. Based on the stability theory of plates and shells, the wrinkling deformation of a rectangular membrane under shear was obtained by post-buckling analysis. Then, by using the wind load derived from a wind tunnel test, the dynamic responses of the wrinkled membrane were numerically analyzed for different wind speeds, wind directions and wrinkling deformations. The results indicate the following: (1) the displacement and extreme stresses of a membrane are gradually intensified with an increase in the wind speed; (2) the wind direction plays an important role in the displacement, but it has little effect on the stresses and (3) the displacement increases with the wrinkling deformation, and the extreme stresses are intensified with an increase in the pre-tension. This study on the wind-induced responses of a wrinkled membrane is helpful to the understanding of the complex behavior of a wrinkled membrane under wind loads while reducing the adverse effects of wrinkling deformation and ensuring the dynamic stability of membrane structures.

Load transfer via a wrinkled membrane

1970 ◽  
Vol 316 (1525) ◽  
pp. 269-289 ◽  
Keyword(s):  
Field Theory ◽  
Strain Energy ◽  
Load Transfer ◽  
Maximum Strain ◽  
Variational Technique ◽  
Membrane Structures ◽  
Wrinkled Membrane ◽  
Tension Field Theory ◽  
Principle Of Maximum

Various problems of planar load transfer from a tie or rod via a wrinkled membrane are considered within the framework of tension field theory. The tension rays, and hence the membrane stresses, are determined by a variational technique based on a principle of maximum strain energy. Results are of interest in the design of lightweight stretched membrane structures.

Ultrastructural Changes of the Tissue Thromboplastin after Intravenous Injection in Rabbits

1978 ◽  
Vol 39 (01) ◽  
pp. 201-209 ◽  
Author(s):  
Hiroshi Hasegawa ◽  
Hiroshi Nagata ◽  
Makoto Murao
Keyword(s):  
Intravenous Injection ◽  
Vascular Endothelium ◽  
Model Experiment ◽  
Venous Return ◽  
Ultrastructural Changes ◽  
Membrane Structures ◽  
Tissue Thromboplastin ◽  
Short Time ◽  
Sheet Membrane

SummaryAttempts were made to demonstrate ultrastructural changes of the tissue thromboplastin after intravenous injection, as a model experiment on the pulmonary microthrombi formation induced by the tissue thromboplastin circulating from venous return.Concentrically arranged membrane structures of the injected thromboplastin disappeared in extremely short time after the injection of the thromboplastin in rabbits. The long sheet membrane of the injected thromboplastin was frequently seen as adhered to the vascular endothelium or to the surface of blood corpuscles. Furthermore, fibrin fibres were formed in contact with the long sheet membrane of the thromboplastin. Membrane structures were not found anywhere in the control rabbits.

Ultramicroscopic and Coagulation-Fibrinolytic Findings Induced by Tissue Thromboplastin

1979 ◽  
Author(s):  
H Nagata ◽  
T Seya ◽  
Y Oguma ◽  
M Yamauchi ◽  
T Murakoshi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Hypercoagulable State ◽  
Membrane Structures ◽  
Transmission Electron ◽  
Single Sheet ◽  
Tissue Thromboplastin ◽  
Short Time

We have studied the ultrastructures of tissue thromboplastin (T.Tbp) to demonstrate how It changes during coagulation.[Materials and Methods] T.Tbp from lungs of rabbits was used for these studies. It was injected into ear veins of rabbits. Lungs were resected at several seconds, 10sec, 1 min, 5 min, 24 hrs or 48 hrs after the injection. They were examined by transmission electron microscope.[Results] Concentrically arranged membrane structures of the injected T.Tbp disappeared in extremely short time after the injection. 1 min after the injection, fibrin fibers were seen between single sheet of membrane and endothelial cells of capillaries. In the rabbit which had died suddenly after the injection of T.Tbp, multiple pulmonary thrombi made of fibrin and platelets were seen in capillaries. The endothelial cells of capillaries were destroyed and interstitial tissues were edematous.The hypercoagulable state was seen 10~30sec after the start of the injection, indicating the shortening of r of TEG. Then, it gradually returned the level before injection. Moreover, changes of the measurements of fibrinogen, antiplasmin and prekallikrein were also seen after the injection.

Boussinesq Wave Model Compared with Field Data

2001 ◽  
Author(s):  
Denis Morichon ◽  
Barbara Boczar-Karakiewicz ◽  
Edward B. Thornton
Keyword(s):  
Field Data ◽  
Wave Model
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