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 behave elastically, i.e., it returns to its original shape after the load is removed. Also, the stress is directly proportional to strain (Hooke's law).

3. Plane Sections Before Bending Remain Plane After Bending: This assumption means that any section of the structure that was flat before the load was applied remains flat even after the load is applied.

4. The Structure is a Perfect Frame: It is assumed that the loads are applied only at the joints and not on the members of the structure.

5. The Effect of Shear Force is Ignored: In many cases, the effect of shear force on the deflection of the structure is much smaller compared to the bending moment. Therefore, it is often ignored.

6. The Self-Weight of Members is Ignored: Unless the structure is very large, the self-weight of the members is usually much smaller than the applied loads and is therefore ignored.

7. All Connections are Hinged: It is assumed that all connections between members are hinged, meaning they can rotate freely. This is not always the case in real structures, but it simplifies the analysis.

8. The Structure is in Equilibrium: The sum of forces and moments in any direction is assumed to be zero. This is a fundamental principle of statics.

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