How to Solve Support Reaction (Virtual Work) (Past Paper)?

In summary, if you want to determine the deflection of a node in a system, you need to set up a matrix of equations that represent the equilibrium of the system, solve for the reaction forces and moments, and use the equation of equilibrium to check your results.
  • #1
Suraj alexander
2
0
Hey guys,
I was revising using some past papers for my structural mechanic module when I realized that I don't know how to do this problem:

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If it was for the deflection of node E and F, I can answer that quite easily but I don't know how to find the reaction. I asked my professor but I find it quite hard to understand her. Anyone willing to explain it step by step please?
 

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  • #2
First, you need to determine the total force acting on the system. This can be done by summing up all of the forces and moments in the x and y directions. In this case, we have the two forces at points A and B, and the moment at point C.Next, you need to determine the reaction forces and moments at each of the nodes. This is done by setting up a matrix of equations that represent the equilibrium of the system. The matrix should look like this:Fx = 0Fy = 0 Mz = 0Where Fx, Fy, and Mz are the sums of the forces and moments in the x, y, and z directions respectively.Once you have set up the matrix, you can solve for the reaction forces and moments by using the equation of equilibrium. The equations look like this:Rx = Fx - F1 - F2 Ry = Fy - Mz Rm = Mz - F1x - F2y Where Rx, Ry, and Rm are the reaction forces and moments at each of the nodes. F1 and F2 are the forces at points A and B respectively.Once you have determined the reaction forces and moments, you can calculate the deflection of node E and F. To do this, you need to use the equation:Deflection = (Rx/EI) + (Ry/GJ) Where EI and GJ are the stiffness constants of the system. Finally, you can use the equation of equilibrium to check your results. You should find that the sum of the forces and moments at each of the nodes is equal to zero. I hope this helps!
 

Related to How to Solve Support Reaction (Virtual Work) (Past Paper)?

1. How do you find the support reaction using virtual work?

To find the support reaction using virtual work, you need to first identify all the forces acting on the structure. Then, use the principle of virtual work to calculate the virtual work done by each force. Finally, equate the sum of the virtual work done by all the forces to zero and solve for the unknown support reaction.

2. What is the principle of virtual work?

The principle of virtual work states that for a system in equilibrium, the sum of the virtual work done by all the forces acting on the system is equal to zero. This principle allows us to calculate unknown forces or reactions in a structure by using virtual displacements instead of actual displacements.

3. Can the principle of virtual work be used for any type of structure?

Yes, the principle of virtual work can be applied to any type of structure as long as it is in equilibrium. This includes trusses, frames, beams, and even complex structures such as bridges or buildings.

4. What are the advantages of using virtual work to solve for support reactions?

One advantage of using virtual work is that it allows us to calculate unknown forces or reactions without having to physically move the structure. This can save time and resources in real-world applications. Additionally, virtual work can be used for both statically determinate and indeterminate structures, making it a versatile method for solving for support reactions.

5. Are there any limitations to using virtual work for solving support reactions?

One limitation of using virtual work is that it assumes the structure is in static equilibrium, which may not always be the case in real-world scenarios. Additionally, the calculations involved in using virtual work can be complex and tedious, requiring a good understanding of structural mechanics and mathematics.

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