Structural Analysis: Specification for Supports in STAAD.Pro

Many of us using STAAD.Pro without knowing proper support specifications. In this post we are providing specifications for supports in STAAD. Pro. We are publishing technical references for STAAD.Pro. in this blog and have published many in here already. We are providing a tab in our top menu and side bar about STAAD.Pro for easy navigation of our viewers.

We all know that without specifying/defining supports, STAAD.Pro will not analyze a structure. So defining a support system is essential and proper definition of support is utmost important to have actual response (moments, shear, axial loads and torsions etc.) to provide proper resistance against this response in designing or proportioning members sizes.

STAAD.Pro provides facilities to assign support both parallel and inclined orientation to global axes. The supports that can be specified are:

a. PINNED

b. FIXED

c. FIXED BUT

d. SPRING

From the definition we know that a pinned support can resist translational movement but provides no resistance against rotation. A fixed support can resist all type of movement in all directions i.e. a fixed support have reactions for all forces and also for moments.

In support condition FIXED BUT is self definitive. There have facilities to make release supports in all desired directions but against forces and moments i.e. Fx, Fy,Fz,Mx,My,Mz and others.

The others contain a translational springs and rotational springs. These springs can be defined as spring constant.

Translational spring:

The input data is translational spring constant. This can be defined as the force required to displace a joint (supported by this spring) one unit length in the direction specified by the user. The direction must be in global axes.

Rotational spring

The input data is rotational spring constant. This can be defined as the force required to rotate a joint (supported by this spring) one degree around user specified direction. The rotation must be referenced global axes systems.

For specifying joints & directions, requiring enforced support displacements this command is also used. Dear reader we will publish springs in relation to mat foundation analysis in this blog very soon.