On the basis of lateral displacement, frames are classified into the following two types

1- Frames without Sway(n0n-sway)

2- Frames with Sway

Non-way frames: if its response to in-plane horizontal forces is sufficiently stiff for it to be acceptably accurate to neglect any additional internal forces or moments arising from horizontal displacements of its nodes.

1- Symmetrical structure and symmetrical loading.

2- Non-sway has only a rotational degree of freedom and a translational degree of freedom is absent.

Some examples of non-sway frames:

Sway frames: there is an in-plane displacement due to horizontal force (or) asymmetrical loading (or) different moment of inertia (or) unequal legs in Portal frame.

Conditions for sway are as follows:

1- If the supports are not in the same position, sway occurs.

2- If the applied load is not acting at the centre of the structure, sway will occur and the structure will sway towards less load side.

Some examples of Sway frames:

Note:Information on sway conditions (intermediate, ordinary, special, and non-sway), slenderness, and their formulation is available through Context Help (Help > Documentation > Concrete Frame > ACI 318-08 > Section 3.4.2).

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