Large strain analysis of rubber-like membranes under dead weight, gas pressure, and hydrostatic loading

1994 ◽  
Vol 14 (2) ◽  
pp. 165-188 ◽  
Author(s):  
H. Bufler ◽  
H. Schneider
Author(s):  
Sydney Harwood ◽  
Parisa Saboori

Abstract The current walking frame used by the elderly has several design issues that can cause long term health problems. One of these problems is the development of chronic pain in the lower back. The design of the current walking frame promotes a slumping posture that causes a curvature in the spine. This curvature results in a large strain in the lower back muscles, specifically the erector spinae. The goal of this research was to design a new walking frame that would be more structurally sound and more practical to use than the present walking frame design. In this study, two literature searches were performed. The first was to explore how aging effects the ability to walk. The second involved studying all of the existing walking devices and analyzing their design strengths and weaknesses. As a result of these studies, three new preliminary walking frame designs were considered that promoted better posture when used, and provided more support than does the present walking frame design. These new designs were considered and tested using a finite element analysis (FEA). From this FEA, it was determined that the new walking frame design resulted in less stress in the lower back than does the present walking frame design. It was therefore concluded that the new model has the potential to decease chronic back pain.


1993 ◽  
Vol 119 (12) ◽  
pp. 2461-2477 ◽  
Author(s):  
G. Wayne Brodland ◽  
Marcus J. Dell ◽  
Eric F. P. Burnett
Keyword(s):  

Author(s):  
Tae-Woan Kim ◽  
Jae-Cheol Kim ◽  
Suk-Hwan Hwang

The safe structural design of boiler waterwalls with various loadings such as dead weight, fluid pressure, gas pressure and thermal differences is an extensive problem demanding the use of sophisticated computation methods due to the complexity of the geometric structure and the large size of the walls. To evaluate the operating reliability of boiler waterwalls, it is essential to know not only overall behavior of the whole structure but also the stress states at the critical zones. In this paper, the structural soundness for the Korea standard 500MW boiler waterwalls is preliminary examined. The equivalent orthotropic plate model is used to investigate the structural behavior of boiler waterwalls under thermal differences. Submodeling technique for part model of boiler waterwalls is proposed to accurately compute stresses of waterwalls at the critical zones under gas pressure. The computed stresses are combined and finally compared with the allowable stress limits according to the criteria of ASME Code.


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