Question 2

Question 2

Generalised Hooke’s Law question 2

A strain gauge is placed at B is inclined 20^o from the horizontal. If the reading on the strain gauge is 350 με, determine the force P acting on the cantilevered beam.

A strain gauge is placed at B is inclined 20^o from the horizontal. If the reading on the strain gauge is 350 με, determine the force P acting on the cantilevered beam.

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Step 1:
Calculate stresses at point B (in terms of P)

Step 1:
Calculate stresses at point B (in terms of P)

Generalised Hooke’s Law solution step 1

Step 2:
Use Hooke's law to convert σ_x, σ_y, τ_xy to ε_x, ε_y, γ_xy

Step 2:
Use Hooke's law to convert σ_x, σ_y, τ_xy to ε_x, ε_y, γ_xy

Generalised Hooke’s Law solution step 2

Step 3:
Construct 2D Mohr's circle using ε_x, ε_y, γ_xy

Step 3:
Construct 2D Mohr's circle using ε_x, ε_y, γ_xy

Generalised Hooke’s Law solution step 3

Step 4:
Find P by getting strain value at θ = 20^o (CCW) from Mohr's circle

Step 4:
Find P by getting strain value at θ = 20^o (CCW) from Mohr's circle

Generalised Hooke’s Law solution step 4

Useful formula:

Useful formula:

Generalised Hooke’s Law formula

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