Stress analysis of basic shapes of membrane structures

2020 ◽  
Author(s):  
Nela Freiherrova ◽  
Martin Krejsa
2013 ◽  
Vol 405-408 ◽  
pp. 989-992 ◽  
Author(s):  
Mohd Syazwan Mohd Noor ◽  
Hooi Min Yee ◽  
Abdul Hamid Haslinda ◽  
Ong Chong Yong

Tensioned membrane structures are pre-stressed membrane structures that are appropriate to be used for long span application. Tensioned membrane structures must depend on their shape and internal pre-stress alone to achieve stability and to carry the loads. Some of the largest stadiums, airports, convention halls and commercial places are tensioned membrane structures. It is essential to perform shape-finding analysis while dealing with tensioned membrane structures. In this study, shape-finding analysis is carried out using computer program for stress analysis which is based on theory of nonlinear displacement method. Shape-finding of membrane surface bordered by Egg has been investigated. In this study, the possibility of adopting the form of Egg as surface shape for tensioned membrane structure has been studied.


2021 ◽  
Author(s):  
Gopichand Ch ◽  
Reshmi Maity ◽  
K. Srinivas ◽  
N.P. Maity ◽  
K. Girija Srav

Abstract This paper presents the simulation and theoretically calculation results of a shunt switch with Electro-mechanical modelling and stress gradient characteristics. The analysis is done with three membrane structures such as plane beam, incorporated with and without perforations, and non-uniform meander type beam, these are simulated in the COMSOL Multi-physics tool. The various Modal analyses are carried out for different values of residual stress gradients such as different structures, materials, and beam thickness. These analyzes are described by the fact that higher stress gradient values ​​are undesirable for switching. By analysing all the results we have observed that the stress analysis for a shows that non-uniform meandered switch experiences maximum stress of 35.6 MPa, and center deflection of 0.06 MPa/μm, the deformations of the beam which is the least among the considered switches.


1984 ◽  
Vol 45 (C1) ◽  
pp. C1-901-C1-904 ◽  
Author(s):  
C. Marinucci ◽  
L. Palladino ◽  
G. Pasotti ◽  
M. V. Ricci ◽  
G. Vécsey

2003 ◽  
Vol 100 (12) ◽  
pp. 1137-1149
Author(s):  
M. François

1978 ◽  
Vol 39 (01) ◽  
pp. 201-209 ◽  
Author(s):  
Hiroshi Hasegawa ◽  
Hiroshi Nagata ◽  
Makoto Murao

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.


1979 ◽  
Author(s):  
H Nagata ◽  
T Seya ◽  
Y Oguma ◽  
M Yamauchi ◽  
T Murakoshi ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document