What are the assumptions made, while finding out the forces in the variousmembers of a framed structure?

When finding out the forces in the various members of a framed structure, several assumptions are made:

1. Material is Homogeneous and Isotropic: The material of the structure is assumed to be the same throughout and possesses the same properties in all directions.

2. Linear Elastic Behavior: The structure is assumed to follow Hooke's law, i.e., the stress is directly proportional to strain. This means the structure will return to its original shape after the load is removed.

3. Plane Sections Before Bending Remain Plane After Bending: This assumption is made to simplify the analysis. It means that any deformation due to bending is ignored.

4. Loads are Applied at the Joints: In framed structures, it is assumed that all external loads are applied at the joints only.

5. Joints are Perfectly Pinned: This means that no moment is transferred from one member to another at the joints. Each member is free to rotate about the joint.

6. Self Weight of Members is Ignored: While analyzing framed structures, it is assumed that the self weight of the members is negligible compared to the external loads.

7. Effect of Shear Force is Ignored: In the analysis of framed structures, it is assumed that the deformation due to shear forces is negligible compared to the deformation due to bending moments.

8. Axial Deformation is Ignored: It is assumed that the change in length of the members due to axial forces is negligible.

These assumptions simplify the analysis of framed structures. However, they may not always hold true in real life situations and hence, the results obtained from such analysis should be interpreted with caution.