- #1

Righthanded123

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## Homework Statement

The problem asks to find out whether the rod yields at points in section A according to the tresca and von mises criteria

P is 120N

## Homework Equations

Shear stress= VQ/It

Stress= Mx/I

shear stress= Tp/J

## The Attempt at a Solution

I picked 2 points at section A.

The first point is on the

I calculated that P will cause a shear stress Vy along the Y axis which is -120N

P will cause a bending moment Mz about the z axis 120N x 250mm

and P will cause a torque Tx about the x-axis 120N x 125mm

At point 1

Vy will not cause a shear stress because Q=0

Tx will cause a shear stress using Tp/J

and Mz will cause a compressive stress which will be at a maximum

Then i found the principal stresses using the mohr circle method

Then using the von mises and tresca criteria I compared the stresses to the yield stress of 200MN/mm to determine if the rod will yield.

At point 2

Vy will case a shear stress found by VQ/It

Tx will cause a shear stress using Tp/J

and Mz will not cause a normal stress because the distance from neutral axis for point 2 is 0 ?

This where I am stuck I am not sure point 2 only has shear stresses as I have calculated

and If i have picked enough points, as i imagine it will be the same values.