stress and strain

[dinbyhcred]

find the maximum load F
D = 35 mm d = 10mm
thetre max = 300 MN/m2
the object is a circular pole

really stuck on finding an equation for this
workings out would be great

 

[Deleted member 4993]

find the maximum load F
D = 35 mm d = 10mm
thetre max = 300 MN/m2
the object is a circular pole

really stuck on finding an equation for this
workings out would be great

What is thetre ?

What is D ?

What is d?

 

[dinbyhcred]

D= IS THE OUTER DIAMETER OF A POLE
d= IN THE INNER DIAMETER OF THE POLE
THETRE MAX= THE MAXIMUM STRESS THAT CAN BE PUT ON THE MATERIAL

 

[Deleted member 4993]

D= IS THE OUTER DIAMETER OF A POLE
d= IN THE INNER DIAMETER OF THE POLE
THETRE MAX= THE MAXIMUM STRESS THAT CAN BE PUT ON THE MATERIAL

What is Stress - in terms of applied load and area of application?

 

[dinbyhcred]

ther is the picture of the question that is all i have
you have to find the maximum loadusing the maximum stress allowed which is 300

 

[Deleted member 4993]

ther is the picture of the question that is all i have
you have to find the maximum load using the maximum STRESSallowed which is 300

But - I need to know whether you know the definition of STRESS (in relation to this problem) or not.

Please tell me - how does your textbook define STRESS. If you do not have a textbook - do a google search and tell us what you find.

 

[dinbyhcred]

stress is = force / area
have to find the maximum Force
the maximum stress has been stated as thetre max

 

[Deleted member 4993]

stress is = force / area
have to find the maximum Force
the maximum stress has been stated as thetre max

Excellent.

Now what is the area they are talking about?

What is the area of the "force application" - or across which area this force is being applied, to create stress in the pole?

 

[dinbyhcred]

the area is the whole area of the pole D and d
and the force is applied where i have shown the f on the picture

 

[Deleted member 4993]

the area is the whole area of the pole D and d
and the force is applied where i have shown the f on the picture

The cross-sectional area (A) of a hollow cylinder - with outer diameter of D[sub:3lhsebsm]o[/sub:3lhsebsm] and inner diameter of D[sub:3lhsebsm]i[/sub:3lhsebsm] is:

A = ?/4 * (D[sub:3lhsebsm]o[/sub:3lhsebsm][sup:3lhsebsm]2[/sup:3lhsebsm] - D[sub:3lhsebsm]i[/sub:3lhsebsm][sup:3lhsebsm]2[/sup:3lhsebsm])

Now calculate the cross-sectional area of the flagpole in the given problem.

 

[Deleted member 4993]

find the maximum load F
D = 35 mm d = 10mm
thetre max = 300 MN/m2 = 300 N/mm[sup:nlnblv87]2[/sup:nlnblv87]
the object is a circular pole

really stuck on finding an equation for this
workings out would be great

\(\displaystyle \sigma \ = \ \frac{Force}{Area}\)

\(\displaystyle Force \ = \ \sigma * Area\)

Area = ?/4 *(35[sup:nlnblv87]2[/sup:nlnblv87] - 10[sup:nlnblv87]2[/sup:nlnblv87]) = 883.5729338 mm[sup:nlnblv87]2[/sup:nlnblv87]

\(\displaystyle Force \ = \ 300 * 883.5729338 \frac{N}{mm^2} * mm^2 \ = \ 265071.8801 \ N \ = \ 300000 \ N\)

The final answer I have reported has 1 significant digit, becuase the minimum significant digit of the problem is 1.