Week 12: Due Friday 2 December
1.
Figure 1 shows the stresses acting on an element of material. Find the three principal stresses
σ
1
,
2
,
3
and the absolute maximum shear stress
τ
max
.
12
12
8
8
6
6
17
17
all stress components in ksi.
Figure 1
2.
The principal stresses at a given point are
1
=
10 MPa,
2
=
-
100 MPa. Sketch Mohr’s
circle for this state of stress and determine the normal stress on a plane inclined at an angle
θ
to
the principal plane 1. Hence find the range of values of
for which the normal stress is tensile.
3.
A glass wire of 1 mm diameter is tested in tension and found to fracture at a tensile force of
40 N.
A similar unbroken wire is used to suspend a mass of 2 kg from the ceiling. The mass is
now subjected to a moment
T
about the vertical axis, causing the wire to be loaded in torsion
as well as tension.
Find (i) the value of
at which the wire will break and (ii) the angle
between the fracture
surface and the cross-sectional (horizontal) plane.
Would your answer to (i) be different if the wire were made of copper?
1
This
preview
has intentionally blurred sections.
Sign up to view the full version.
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 10/05/2011 for the course MECHENG 211 taught by Professor ? during the Fall '07 term at University of Michigan.
- Fall '07
- ?
- Shear, Stress
-
Click to edit the document details
