How Accurate Is the Analytical Method for Calculating Truss Forces?

AI Thread Summary
The discussion focuses on the accuracy of analytical methods for calculating truss forces, specifically addressing a user's calculations for joint A and member AD. The user is uncertain about their results, particularly regarding the force in member AD, which they initially assumed to be in compression. Feedback indicates that a negative force value suggests the actual force direction is opposite to the assumption made in the free-body diagram. The user is encouraged to reassess their calculations with this clarification in mind. Accurate interpretation of force signs is crucial for correct truss analysis.
Stacyg
Messages
23
Reaction score
0
Hi. The question is attached as well as my attempt at the answer, which I'm pretty sure is at least partially wrong. I have'ne included my calculations at point B as I have uploaded the limit of 3 files but I got BC=18.30kN (compression)
Any help would be great thanks.
 

Attachments

  • Question.png
    Question.png
    12.6 KB · Views: 428
  • Answer Pt 1.png
    Answer Pt 1.png
    18 KB · Views: 438
  • Answer Pt 2.png
    Answer Pt 2.png
    22.1 KB · Views: 408
Physics news on Phys.org
I'm having some trouble with legibility of the files; so I only checked joint A. Although I cannot really read it, it appears everything at joint A is correct, except on your free-body diagram you assumed the force in member AD is compression. Then when that force variable turned out to be negative, you claimed the force is compression. That is incorrect. Negative means the force is the opposite of the direction you assumed for the unknown vector in your free-body diagram. Try it again.
 

Similar threads

Truss Method of Joints: Solving Unequal Member Forces
Replies
2
Views
2K
Calculate Force Member in Truss
Replies
2
Views
2K
Truss Analysis : Method of Joints only (Picture provided)
Replies
1
Views
2K
How do I calculate forces in a truss cross section?
Replies
2
Views
583
Engineering Determining Force and Directions on Truss with Pulley
Replies
7
Views
2K
Having trouble calculating reaction forces for this truss.
Replies
7
Views
3K
How to check the Stability of ANY Truss?
Replies
1
Views
2K
How Do You Calculate Distributed Load on a Roof Truss Due to Snow?
Replies
3
Views
5K
Statics - Compression and tension forces in a truss
Replies
2
Views
6K
How do I calculate the forces in a Truss?
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top