Introduction to Elasticity/Wedge with boundary tractions

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[edit] Wedge with Boundary Tractions

Elastic wedge with normal and shear surface tractions

Suppose

  • The tractions on the boundary vary as r^n\,.
  • No body forces.

Then

\text{(1)} \qquad \varphi = r^{n+2} f(\theta)

To find f(θ) plug into \nabla^4{\varphi} = 0.

\text{(2)} \qquad \left(\frac{d^2}{d\theta^2} + (n+2)^2\right) \left(\frac{d^2}{d\theta^2} + n^2\right) f(\theta) = 0

If n \ne 0 and n \ne -2,

\text{(3)} \qquad \varphi = r^{n+2} \left[ a_1 \cos\{(n+2)\theta\} + a_2 \cos(n\theta) + a_3 \sin\{(n+2)\theta\} + a_4 \sin(n\theta)\right]

The corresponding stresses and displacements can be found from the tables associated with Michell's solution. We have to take special care for the case where n = 0, i.e., the traction on the surface is constant.

[edit] Sample Homework Problem

Find the stresses and displacements for a wedge loaded in constant shear S on its surface.

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