1 Introduction
2 Finite Element Analysis
2.1 Finite Element Modeling
Elastic modulus \({\varvec{E}}_{11}\) (GPa) | 41.498 |
Elastic modulus \({\varvec{E}}_{22}\) (GPa) | 13.730 |
Shear modulus \({\varvec{G}}_{12}\) (GPa) | 4.85 |
Poisson’s ratio \({\varvec{\upsilon}}_{12}\) | 0.267 |
Tensile strength (MPa) | 1167.87 |
Compression strength (MPa) | 583.93 |
Shear strength (MPa) | 65 |
3 Numerical Analysis and Discussions
Model | Displacement of indenter (mm) | Orientation of indenter (°) | Buckling capacity (kPa) | Difference with perfect shell (%) |
---|---|---|---|---|
S-100-2-0 | 2 | 0 | 24.55 | 25.38 |
S-100-2-90 | 2 | 90 | 24.55 | 25.38 |
S-150-2-0 | 2 | 0 | 30.84 | 6.26 |
S-150-2-90 | 2 | 90 | 30.99 | 5.80 |
S-200-2-0 | 2 | 0 | 30.94 | 5.95 |
S-200-2-90 | 2 | 90 | 31.26 | 4.98 |
S-100-4-0 | 4 | 0 | 24.47 | 25.62 |
S-100-4-90 | 4 | 90 | 24.49 | 25.56 |
S-150-4-0 | 4 | 0 | 24.75 | 24.77 |
S-150-4-90 | 4 | 90 | 24.96 | 24.13 |
S-200-4-0 | 4 | 0 | 25.02 | 23.95 |
S-200-4-90 | 4 | 90 | 24.73 | 24.83 |
S-100-6-0 | 6 | 0 | 24.36 | 25.95 |
S-100-6-90 | 6 | 90 | 24.44 | 25.71 |
S-150-6-0 | 6 | 0 | 19.61 | 40.39 |
S-150-6-90 | 6 | 90 | 19.95 | 39.36 |
S-200-6-0 | 6 | 0 | 19.93 | 39.42 |
S-200-6-90 | 6 | 90 | 20.77 | 36.86 |
S-100-8-0 | 8 | 0 | 24.31 | 26.10 |
S-100-8-90 | 8 | 90 | 24.39 | 25.86 |
S-150-8-0 | 8 | 0 | 19.50 | 40.72 |
S-150-8-90 | 8 | 90 | 19.58 | 40.48 |
S-200-8-0 | 8 | 0 | 19.37 | 41.12 |
S-200-8-90 | 8 | 90 | 19.55 | 40.57 |
4 Conclusions
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The failure mode of both models is fibre compression type, and the area of damage increased with increasing the value of dent depth.
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For a dent depth of 8 mm and before applying the external pressure, the fibres were damaged by approximately 80% due to local stresses beneath the indenter.
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The effect of indenter orientation on the buckling capacity of the cylindrical shell models was negligible.
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Whilst the location of the dent depth significantly affected the buckling capacity of the cylindrical shells, the dent depth had a negligible influence on the shells’ buckling capacity.
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The effect of dent depth on the reduction in the buckling capacity of the cylindrical shells increased from shell mid-height towards the 2/3rd of shell height.
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By placing the indenter in the middle and near the upper edge, the buckling capacity decreases with the increasing of the amplitude imperfection.