Abstract:
This report presents a method for fabrication of a
conoidal shell model. Moreover the experimental investigation
on this model regarding deflection and stress
distribution is presented.
The aim of the study was to investigate the stress
pattern. deflection and overall behaviour of the conoidal
shell model at service (design) load level and also at
higher load levels. The study includes the comparison of
the test results with those available in literature.
The test results show that bending moment developed
throughout the shell body in addition to the membrane stress
resultants. The location of maximum bending moment was near
the interfaces of the shell and the edge members. Stress
condition near the low end diaphragm was significant. The
entire'shell bOdy remained in compression and no tension
developed under loading conditions. The deflections were
found to be .small at the service load level. The measured
compressive stresses were.well below the allowable compressive
strength of the constituent materials. moreover,the
measured stress resultants were comparable with those obtained
from the membrane analysis. From the model testing no crack was observed at s~rvice
load level and only a few hair line cracks were observed at
the edges of the shell at double the service load.
It was thus observed that in the conoidal shell model
(which was designed on the basis of membrane analysis) bending
moment of small magnitude developed under service load
condition. Moreover, the membrane stresses were comparable
to those obtained by membrane analysis.
