Civil Engineering - GATE Exam Questions - Discussion

@All.

SLOPE DEFLECTION METHOD:

* Slope deflection method was proposed by George A. Maney in 1914.
* The slope deflection equation will give the relationship between B.M rotation and deflections.
* The number of simultaneous equations to be solved in the slope deflection method is equal to the number of joint displacements in the structure.
* In the slope deflection equations, the deformations are considered to be caused by B.M only.
* In slope deflection method, joint rotations are taken as unknowns.
* Slope deflection method is used to find S.F. and B.M. in a structure in which Slope and deflections are unknown.
* Slope deflection method can be used to analyse All the structures (Fixed beams, Continuous beams, Multi-storey portal frames).
* The slope deflection method of structural analysis is a method of displacement.
* Slope deflection method can be used to solve Statically indeterminate beams/statically indeterminate structures.

Answer should be 'Degree of Kinematic Indeterminacy'. Slope Deflection method is a kinematic method. The unknowns in this method are the unknown displacements or translations and unknown rotations at joints of any structure which is subjected to bending. Hence the number of simultaneous equations to be solved in the slope deflection method, is equal to degree of kinematic indeterminacy.

@Vinay.

It is no of joint rotation and not number of joints
In the non-sway frame, only rotation of joints considered as an unknown, which is nothing but the degree of kinematic indeterminacy.
In sway frame sway of frame i.e. horizontal displacement of the frame is additional unknown, which is also nothing but the additional degree of kinematic indeterminacy.

Whatever the forces formed are acting in any type of structure, will act on joints (imagine all supports can be considered as joints, but joints are not supports). Force can act horizontal & vertical at any joints. Generally to get unknown forces we will prepare equations accordingly.

We can not form the equation at the fixed support (joint). So it will not depend on joints. It will depend on kinematic indeterminacy. We can form the equations at intermediate and simple joints only. Because there only kinematic indeterminacy is possible.

No I didn't think so, it depends on the degree of kinematic indeterminacy. Think of a frame which can be both sway & non-sway. In former case equations are 2 while in later case it is 3.

They are asking about a number of simultaneous equations that to be solved in SDM. It is equal to no of joints in the structure.

But in SDM, no of unknowns = Kinematic indeterminacy.

Statical indeterminacy =strain energy method, it is support action.

Kinematic indeterminacy=flexibelity method, stiffness (or) displacement method, it is joint action.

Clearly explained @Vinay "joint displacement" NOT "no of joints". So joint displacement is nothing but kinematic indeterminacy. Option is B.

Consider 1 frame equation to be solve is 3 now explain how it depends on joint.

It depends on KI neglecting axial deformation.