Friday, 17 April 2015

What's new in ConSteel 9 and csJoint 9

On the occasion of releaseing the 9th version of ConSteel and csJoint, we managed to give a Webinar about the fresh features.

If anyone missed it, it is available on Youtube now:
ConSteel webinar - What's new in ConSteel 9 and csJoint 9

Some of the new features are:
-Plastic hinge analysis
-Frame corner wizard
-Crane and moving load
-Buckling sensitivity (automatic selection of elastic critical factor for buckling check)
-Design of spread foundations
-Automatic meteorological load generation

Tuesday, 7 April 2015

Tips & Tricks

Start/End-releases of bar members

Most of the model failures are in connection with incorrectly defined start/end-releases. ConSteel is always working in 3D,  so understanding the behavior of the connectivity between members is essential for a properly built model. With release problems Analysis cannot be initiated, error messages will appear which can be frustrating if we do not know how to handle them.

Related Error messages:
"Model instability on the x. finite element node."
"Error in release definitions."
"Model error! Please check the support conditions, especially the twist of members!"

In most cases one or more of the degrees of freedom are set to "free", which causes model instability, and actually it lets to a bar member to twist around its own axis

What are start/end releases are for?
With start/end releases you can set, how a selected bar member should join to another (For example a purlin, to a beam, or a bracing element to a beam).
With practically chosen releases, real life situations can be better approximated, design can be more accurate.
Local coordinate system of a bar member

Every member (bar, support etc) in ConSteel has its own local coordinate system. In case of bar members, the local X axis is always the reference axis, the Y and Z axis are the major and minor axis of the cross section (See the picture).

By setting start/end-releases, you can allow or fix relative displacements of the endpoint of the chosen bar member in the direction of (local) axes (X,Y,Z), and rotation around the three local axes (XX,YY,ZZ). Furthermore, you can allow or fix warping, with the „w” parameter.

In ConSteel, there are predefined releases to choose from, but new, custom releases can be created too. For example, yy,zz release means, that the bar member can rotate around its local Y, and Z axes at the start/end point. This release type is typical for bracing elements. See picture below

Release setting