How to determine the diameter of a cable

  • #1
packersfan851
1
0
A Cable that has a yield strength of 620 MPa and a safety factor of 3. This cable must be able to support 5 buckets which must be able to carry up 5,429.554 kg each.
Bucket mass is negligible.

Stress = Mass/Area
Area = force/stress

My attempt at a solution:
Total weight 5 buckets must carry = 5,429.554 kg * 5 = 27147.77 kg

Area = 27147.77kg * 9.8ms^2 / 206.667MPa x 10^6
Area = .00128

.00128 = ∏d^2 / 4
.00164 = d^2
.040496m = d
or 40.497mm

I know this is probably all wrong.
 

Answers and Replies

  • #2
rock.freak667
Homework Helper
6,223
31
That looks correct to me, your method at least, I don't have a calculator right now to check your numbers.
 
  • #3
CWatters
Science Advisor
Homework Helper
Gold Member
10,545
2,317
Calculation looks ok as well.
 
  • #4
cmmcnamara
122
1
Wouldn't this methodology be a bit wasteful design wise? In addition to utilizing a specified factor of safety the loading is then taken to be occurring in one specific point as a combined whole when in reality the buckets are five distinct and spaced point loads?
 
  • #5
CWatters
Science Advisor
Homework Helper
Gold Member
10,545
2,317
I guess you are right. You could use a different diameter for each section of rope. eg getting thicker as you go up and the load increases. Not clear if that would reduce cost though. In practice the joints and method of attaching the buckets would complicate the issue.
 

Suggested for: How to determine the diameter of a cable

Replies
5
Views
221
Replies
2
Views
230
  • Last Post
Replies
13
Views
238
Replies
8
Views
582
  • Last Post
Replies
3
Views
296
Replies
2
Views
156
Replies
10
Views
709
  • Last Post
Replies
4
Views
434
Replies
15
Views
1K
  • Last Post
Replies
3
Views
332
Top