CSE wishes to be an open program. So every software house producing a fem software may interface with CSE. From a general point of view, the interface with CSE can be done at two different levels, which we will call level 1 and level 2.

In level 1 a finite element model already solved, prepared in an external fem program, let's call it MIKEY, is passed to CSE in order to design the connections. The user has already defined and checked the members, and internal actions for all combinations are known. Moreover, the cross-sections and materials of every member (or better: finite element) have already been assigned and probably also checked. Going from this FEM program to CSE is thus going from a wireframe (fem) environment, to a full 3-D world.

 In order to do that the software house which develops the program MIKEY, or a user who uses it, has to write a text (ASCII) file with the extension .SR4. File format .SR4 is quite simple and has been designed to let each user of other program, or each software house, as well, to easily create an exchange file which can be read into CSE. (1,6Mb)
PortalFrame.txt   SR4 FILE (a simple portal frame) (5kb)

files .txt must be renamed .sr4 for CSE.

In a previous stage of development a different file format, binary, not ASCII (text), was also prepared. This means that a developer may use this file format (named .SR3) instead of the text file format (named .SR4). This approach is more precise (because numbers are written binary, so in double precision), but also more complex. This file format has been prepared (.SR3) and is described in the files contained into the zip file which can be freely downloaded here below. Basically MICKEY will write four files for each model:

  • a .sr3 binary file which describes the fem model
  • a .ddb binary file which describes the computed displacements
  • a .sdb binary file which describes the computed stresses and internal forces
  • a .rdb binary file which describes the computed constraint reactions (1,5Mb)

Once these files have been written (one text or four binary) MIKEY can directly call CSE (as explained in ZIP file DOCS) in order to directly pass the fem model to CSE. From that point forward the user will work in CSE to define his/her connections, and using the internal forces computed by MIKEY, as written in exchange file.

So every program can be linked with CSE with not a too great effort. Software houses interested can freely download ZIP file and study docs. Then they can send us sets of files  to be freely tested by us. For possible commercial agreement please write to

Since our fem program is named Sargon, the open-fem model file format is called Open Sargon. Sargon, as well as CSE, can read directly .SR4 (text) and .SR3 files. Of course you will use or .SR4, or .SR3.

Level 2 link between other programs and CSE has been developed. Here the user has already designed a possible configuration for his/her connections, that is in our terminology the scene has already been set up, for a set of connections. The link should pass not only info about a fem model, if any, but detailed info about how the REal NODE has been designed. The user will so get into CSE with all ready but the choices about how to compute and check the RENODE components (i.e. bolts, welds, stiffeners, plates, and so on). Moreover, if some modification has to be done into CSE, the caller program, say DONALD, will have to be informed. The link is therefore bidirectional. Currently (April 2016) CSE is able to read and write information about components in several CAD file formats. We have set up a new file format, named .D3O, which is able to manage all the information needed to import and export the components to and from CSE. This file format is easy and can therefore be used as preferred choice by third parties to develop their own interfaces to CSE.

D3O_FormatSpecifications.pdf   D3O format specifications

Prova1.sr4   SR4 file example: fem model

Prova1.d3o   D3O file example: components definition

Prova1.png   Resulting node

Last upgrade: April 12, 2016







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