NextFEM Designer allows the export of the model to IDEA StatiCa® for the analysis of bolted or welded steel joints. In this article we’ll see an application for a welded joint between transom and standard in a prefabricated frame scaffolding analysed with the Struct module.

 

Starting from the last version 1.4 update, NextFEM Designer supports the export of the entire model to the IDEA StatiCa ® Connection program, which allows the advanced design of steel joints, both bolted and welded. The export takes place through the File / Export command, selecting "IDEA StatiCa" as file type. If results are present in the model, they will be exported to a file. xmlR that’ll be read automatically. StatiCa can be started automatically if the file path " IOM_IDEAConnectionRunner.exe " in the mask " miscellaneous " Tools / Options (typically " C: \ Program Files \ IDEAStatiCa \ StatiCa10 ) has been set.

To make a single joint visible to IDEA StatiCa Connection, simply set the "Node-> Joint" attribute from the "Edit / Change element type" command.

 

 

StatiCa works with structures composed of members already correctly dimensioned and verified, and deals with the calculation and verification of joints in an advanced way. In the example below the joint between the transom and the standard of a scaffold with prefabricated frames is analysed, as shown in the following figure.

The scaffolding was loaded with a variable of 6kN / m2, project load for heavy construction scaffolding. All the members have been previously verified through the Scaffolding Verification of NextFEM Designer Struct module.

The node is ready for analysis after the addition of the weld , which we assume to have a height of weld beads of 2.9mm for the node 53 and 2.3mm for the node 49. In the event that one of the converging rods in the node is not correctly sized to support the project loads, IDEA StatiCa reports this by blocking the calculation of the joint.

 

 

The connection is named by the original node number. Let's see some IDEA StatiCa elaborations for nodes 53 (transom-standard) and 49 (wind brace - standard).

 

(a)

(b)

Contour view of the deformation of the first collapse mode from stability analysis in IDEA StatiCa ® of the riser-to-cross node (a) and deformed and contour of the tension of the riser node (b)

 

Figure (a) shows the collapse deformation of the node due to local instability of the standard. This tool therefore allows the determination of the collapse load of the node, which is in any case subordinated to the stability of the connected rods. A welded joint in a normally sized scaffold is generally much more resistant than the connected beam.

In figure (b) the stress distribution in the node 49 can be appreciated at the base of the welding. This turns out to be the most stressed point of the scaffolding frame: the program indicates the collapse multiplier (i.e. the maximum factor by which we can multiply the project loads without the structure collapsing) is the lowest among all the nodes of the frame.

 

NextFEM Designer together with IDEA StatiCa are the perfect match for the design and verification of steel structures.