Trusses- Analytical Method.

In summary, the conversation discusses a question and answer regarding calculations for joint A. The person asking for help is having trouble with legibility of the files, but the expert suggests checking joint A and points out an error in assuming the force in member AD is compression. The expert advises trying again.
  • #1
Stacyg
25
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: 372
  • Answer Pt 1.png
    Answer Pt 1.png
    18 KB · Views: 398
  • Answer Pt 2.png
    Answer Pt 2.png
    22.1 KB · Views: 364
Physics news on Phys.org
  • #2
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.
 
  • #3


I would like to provide some feedback on your attempt at solving the truss problem using the analytical method.

Firstly, it is important to clearly define the problem and its assumptions. From the given information, it seems that the truss is in static equilibrium and all the members are assumed to be perfectly rigid and connected at the joints without any friction.

Next, your approach to solving the problem using the method of joints is correct. However, there are a few errors in your calculations that need to be addressed.

1. In the calculation of forces at joint B, you have correctly identified that the force in member DE is zero. However, the forces in members AB and BC are not equal. In fact, the force in member BC is in compression and should be equal to 18.30 kN. This can be verified by taking moments about joint B.

2. In the calculation of forces at joint C, you have assumed that the force in member AB is in tension. This is incorrect. The force in member AB is in compression and should be equal to 12.20 kN. Again, this can be verified by taking moments about joint C.

3. It is important to note that all the forces in the truss are in equilibrium and therefore, the sum of all the vertical and horizontal forces must be equal to zero. This can be used to verify the accuracy of your calculations.

I would also like to suggest that you label the forces in the truss correctly. The convention is to use arrows pointing away from the joint for tension forces and arrows pointing towards the joint for compression forces.

In conclusion, the analytical method is a useful tool for solving truss problems. However, it is important to pay attention to all the details and assumptions, and to double check your calculations for accuracy. I hope this helps in your understanding of trusses and the analytical method.
 

What is the analytical method for analyzing trusses?

The analytical method for analyzing trusses involves using mathematical equations and principles to determine the internal forces and reactions within a truss structure. This is done by applying the equations of static equilibrium and solving for the unknown forces using various methods such as the method of joints or method of sections.

What are the advantages of using the analytical method for truss analysis?

One of the main advantages of using the analytical method is that it provides precise and accurate results for the internal forces and reactions within a truss. Additionally, it allows for the analysis of complex truss structures that may not be possible with other methods. It also allows for the optimization of truss designs by adjusting member sizes and configurations to meet desired load requirements.

Are there any limitations to the analytical method for truss analysis?

Yes, there are some limitations to the analytical method. It assumes that the truss is perfectly rigid and that all joints are connected by frictionless pins, which may not always be the case in real-world structures. It also requires a good understanding of mathematics and structural mechanics, which may be challenging for some individuals.

Can the analytical method be used for any type of truss?

Yes, the analytical method can be used for any type of truss, including simple and complex truss structures. However, the method of joints is typically used for simple trusses, while the method of sections is more suitable for more complex truss designs.

What are some common applications of the analytical method for truss analysis?

The analytical method is commonly used in the design and analysis of various structures, including bridges, roofs, towers, and cranes. It is also used in the construction of support structures for buildings, such as trusses used in roof systems. The method is also useful in the analysis of truss structures in the aerospace industry.

Similar threads

  • Mechanical Engineering
Replies
1
Views
643
  • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
8
Views
894
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
5K
  • Engineering and Comp Sci Homework Help
Replies
7
Views
2K
  • Differential Equations
Replies
9
Views
1K
Back
Top