© 1987 by Oxford University Press
THE REINFORCEMENT OF A HOLE IN A FLAT PLATE BY CYLINDRICALLY WOUND FIBRE-REINFORCED DISCS
( Department of Theoretical Mechanics, The University of Nottingham University Park, Nottingham NG7 2RD )
Holes in stretched plates are sources of stress concentration. A potential method of alleviating this stress is by reinforcement with cylindrically wound fibre-reinforced annular discs bonded to the lateral surfaces of the plate. Mansfield (2, 3, 4) has given a three-dimensional analysis of the stress in this configuration for the axially symmetric case. This analysis is restricted to plates and discs of uniform thickness and requires quite extensive computation. We present an approximate analysis based on the property that the elastic modulus for extension in the fibre direction greatly exceeds other relevant moduli. This analysis can be applied for any uniform stress at infinity, and permits variations in thickness of the plate and the reinforcing discs. In particular we consider the cases of all-round tension and pure shear at infinity. We also consider linearly tapered and countersunk, as well as uniform, reinforcing discs. For uniform discs and all-round tension, excellent agreement with the results of Mansfield is obtained. For the cases considered, it is found that tapered and countersunk discs give slightly more efficient reinforcement than uniform discs. Graph are presented which enable optimal reinforcement profiles to meet appropriate design criteria to be determined