Stress And Deflection Analysis of Cracked Composite Pressure Vessel by Finite Element Method
No Thumbnail Available
Date
2015-10
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The aim of this thesis is to develop crack and investigate techniques and parameters that could be
used to identify crack if it exist in a composite pressure vessel. Many researchers discovered
formation or propagation of a crack in a composite pressure vessel will cause a catastrophic
failure. Thus, health monitoring for a pressure vessel due to crack using crack detection
techniques will minimize or reduce the failure that probably to occur.
This research first focused on mathematical and numerical relation which, represent the
governing equation of composite material winding on in a pressure vessel. For modeling
different crack size in the composite overwrapped pressure vessel fracture stress theories applied.
Different surface Crack size are considering according to the literature standard values. Model
actual size of composite pressure vessel with varied crack size “a” develops on the surface of
composite pressure vessel. This research thoroughly analysis the effect of crack on the surface of
composite pressure vessel. Those parameters are considered to see the variation of result due to
presence of crack. The main parameters are considering stress, principal stress, von mises stress,
deflection and fracture stress. According to the parameters it shows that as crack size increase,
the average stress will be increase with the given pressure in composite pressure vessel. In
contradict; the fracture stress will be decrease as the crack size increase.
In this study, optimal angle-ply orientations of symmetric [550, -550] shells designed for
maximum burst pressure with allowable crack size were investigated. It is shown that all the
strength characteristics of carbon fiber relevant to structural engineering can be explained by the
cracks present in the carbon fiber and can be analyzed using fracture mechanics. The stress and
deformation are affected due to the presence of crack in composite pressure vessel. These
parameter are takes a design crack as the basis for design. Rather than an allowable stress as in
current approaches, with which it is compared cracked composite pressure vessel. A full size
cylindrical shell of composite pressure vessels is conducted. A mathematical method, A finite
element method and compare experimental test are studied to verify a maximum allowable crack
size in composite overwrapped pressure vessel with a given optimum winding angles. The roll of
crack size design within the wider philosophy of limit state design is discussed.