Other components of the strain tensor are zero, so that:
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(12.3) |
Integrating, the displacements can be given as
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(12.4) |
The formulae for the displacements show that the cross-sections remain plane but the planes are rotated so that they pass through the centre of curvature. Shape of the cross-sections is changed. For example if the cross sections initially are rectangular with boundaries in a plane , these boundaries will become the curves given respectively by,
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(12.5) |

For a rod with rectangular cross-section (sides ) the principal moments of inertia are
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(12.6) |
For a rod with circular cross-section, with radius , the moment of inertia is
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(12.7) |
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