How 3 DOFS shouldn't it be 6?

Yes

@@creationmodelling42 That is because we want them have 3 DOF's (only translational) per node in Solid Elements. First and the foremost reason is to actually make the calculations a bit less time consuming and complex. A node having 6 DOF's means that the node is able to resist and transfer forces in 3 DOF's (translational) while moments in other 3 DOF's (rotational). In solid elements, this is not the case. A solid element is not supposed to resist and transmit the moments. That is because in the reality it cannot. The moment transfer happens in terms of equal and opposite forces. Therefore, only 3 DOF's (translational) are enough which are used to resist and transfer forces. However, for a shell and beam element, a node is supposed to carry and resist the moments, thus rotational DOF's are a necessity. But this should be remembered that nothing in reality is 2D and 1D. We are trying to represent the reality in FEM.

Isn’t the 1D beam element has 4dof ?? XY on one node and XY on another ?? (2 translational at 2 each node) Also the 2D element (shell element ) has 4 nodes hence 8 translational and 4 rotational = 12 nodes . And the 3D element has 8 nodes hence 24 translational (3 on each node) and 24 rotational (3 on each node along 3 translational axis) =48

Ravi Kumar - This is a job leading course and comes with Job assistance!

rahul k - this information generally depends on the type of element. 6 is the maximum number of dofs that are possible, per node. Usually, you can look at the element definition to get this information.

@@SkillLync Okay, sure will do.

Degree of freedom is defined as the minimum number of independent coordinates to represent all possible positions of a node

How? 3D objects have rotational as well and for 1d object it should be less and as well for 2d objects?