Importare .dat

Sargon/ CSE offers the ability to import models prepared in STRAP. As well as importing the model, Sargon/ CSE can also import and convert the results of the analysis carried out in STRAP.

In order to start the conversion from STRAP file format to CSE or SARGON file format, the user must choose a .dat file which identify the model. In the subfolder where the model files are written, there may be several other STRAP models, so choosing the .DAT of the model we are interested in, simply works to define the model number we are interested in.

1) Ask to STRAP to create a report file for the model at hand, with a suitable file format.

2) Read the report file created by STRAP and convert it into a CSE or SARGON file.

As phase 1 requires STRAP STBATCH.EXE, an installed and working copy of STRAP must be available in the computer, including the relevant protection key. Sargon/CSE automatically creates the run file and the report file format required by STBATCH.exe to print the report, and automatically runs STBATCH itself. In order to run STBATCH, the STRAP folder must be known to the program CSE/SARGON which performs conversion. It is initially assumed that STRAP is in "C:\STRAP1" folder. If this is true (a copy of STRAP is found in that folder) the program moves on, without asking further information. If there is not an available copy of STRAP in "C:\STRAP1" folder, the program looks for the environment variable named "STRAPFOLDER". This environment variable may be set once for all by the user in order to teach CSE/SARGON where to find STRAP. In order to set an environment variable just go to Control Panel, choose Security and System, System, Advanced Settings, and choose "Environment variables". A dialog will appear, choose "New". Set as the name of the variable "STRAPFOLDER" and as "value" the folder where actually STRAP is, e.g. "C:\STRAPNEW". If the environment variable is found, the program will run STBATCH in the folder specfied by the environment variable. If the environment variable does not exist, then the program will ask the user to input the folder where STRAP is placed, issuing a warning that such input may be avoided by properly setting the environment variable STRAPFOLDER.

Report file will be named CSE*.DAT (if using CSE, or WSR*.DAT if using Sargon). Its format has been prepared to be read by Sargon/CSE. So, when GEOM001.DAT is imported in CSE, STBATCH.EXE will print CSE001.DAT, in the same folder of STRAP model. Then CSE will automatically import CSE001.DAT, creating a CSE001.CSE model and its related results files (CSE001.DDB, CSE001.SDB and CSE001.RDB, for displacements, stresses/forces and constraint reactions). User can choose a different name for CSE (or Sargon) model.

Some specific aspects of the main issues encountered when writing the conversion procedure are discussed in more detail below.

Before reading STRAP's report file, CSE asks the user if vertical global axis in STRAP model is X2 or X3. According to user's choice, one of the following correspondences will be assumed (STRAP's vertical axis is highlighted).

Since some information about materials is missing in STRAP (steel yield stress, for example) when the model is imported user can choose to apply one of the materials from CSE/Sargon.sma archive or define missing properties (yield stress and ultimate stress) one by one. After the importing, user can change or modify materials for desired elements, if needed.

Before opening and reading the model which is to be imported, the conversion routine reads and imports the cross-sections needed in order to establish a suitable match between the sectional forms in Sargon/CSE and those in STRAP.

The mapping file between CSE and STRAP cross-sections is called "WSR_STRAP_SHPCVT.TXT" and can be found in the CSE installation folder. This file will be used when a STRAP model is imported into Sargon/CSE. This file, known as the "mapping file", is usually the same for Sargon and CSE, and is structured as shown below.

The second column lists the corresponding section names in STRAP. This is build by adding three strings: 1) the string referred to the kind of the cross-section; 2) the letter "&"; 3) the cross-section name in STRAP (which has no kind attached).

A section is identified by its name. If the name "beta" in STRAP corresponds to the name "alpha" in Sargon/CSE, then the sectional form "alpha" will be mapped to "beta". To find out the properties of the sectional form "alpha", the program must open an archive of sectional forms of type .SMA (an .SMA file); in particular:

•if Sargon is in use, this will be the file "sargon.sma" in the Sargon program folder;

If the first line of the mapping file contains a "$" or "\\" symbol that means it is a comment line.

The first 18 characters of the names are used for matching purposes. For two names to be matched, each of these 18 characters must be identical.

The conversion file is easy to manage and the user can add any lines they require. The user may actually wish to edit the file "WSR_STRAP_SHPCVT.TXT" in order to add more conversion lines. So, if a cross-section used in a STRAP model has not been automatically detected by conversion program, the User may whish ad add the section in CSE.SMA archive by using SAMBA program, and then edit the conversion file, establishing a match between the STRAP cross section and the new cross-section just added into the CSE.SMA archive by using SAMBA.Conversion file includes sections from European, British, American and Indian archives. As at October 2012, the conversion file contained around 2,000 sections (Europe, UK, US, India).

1.The cross-sections in the .SMA file relevant to the program in use (Sargon or CSE) are read.

3.The sections in the STRAP model are read and then transformed into Sargon/CSE-type sections following the procedure below.

A.The following sections are read by using their dimensions (no conversion file used): rectangular (property type, PT, =1); pipe (PT=2); tube (PT=3); L (PT=4); I (PT=5); [ (PT=6); T (PT=7), circle (PT=8).

B.If property type is equal to -1, the cross section is read from table, and conversion file will be used. If the cross-section is of the types "><", "2L", "[]", "][", the program decodes the name of the simple cross-section, and searches this cross-section in the conversion table. The complex cross section will be rebuild using simple cross-section and the distance between the two cross sections. The simple cross section name is found by performing the following tasks. If the string "><" is followed by "L130x90x12", in STRAP report file, the program should rebuild the proper cross section name in the second column of conversion file. To do that, "L130x90x12" must be replaced by "L&130x90x12". The keyword kind "L" must then be searched for and separated by size. So for angles the program searches for the following possible keywords: "L"; "E.ANGLES"; "U.ANGLES". For channels the program searches the following possible keywords: "UNP"; "UAP"; "CHANNELS".

C.Some sections are not supported and are not imported: if detected, they are replaced with a rectangular fictitious shape in order to complete the importing. User can then assign the desired shape defining it directly in CSE, without loss of results. Otherwise, user can add the needed sections to Sargon/Cse.sma archive and adding the related conversion lines in WSR_STRAP_SHPCVT.TXT.

It is as well to note that any user can always ensure that a sectional form in STRAP is converted correctly to a sectional form in Sargon/ CSE, simply by satisfying themselves that the desired form is present in the .SMA archive and that the Sargon/CSE-STRAP mapping between the names of the two sections is available in the mapping file. Once carried out, the work will of course apply every time those sections are used in any model in the future.

When installing upgrades, in order to avoid overwriting your mapping files and SMA archives, it is advisable to take a backup copy of both the mapping file and the SMA file.

When two non standard cross sections are matched (CSE/SARGON archive versus STRAP) it is important to check that the principal axes of the cross-sections are the same.

STRAP prints results in the report for combinations only. For this reason, in addition to "true" combinations, user must define n "fictitious" combinations, one for each load case. A combination is automatically recognized as "fictitious" by CSE if it contains a multiplication factor equal to 1.0 for one load case only, and 0.0 for all the other load cases (for example, combination = 1.0 * case1 + 0.0 * case2 + 0.0 * case3 + 0.0 * etc.). See the example in the following table (fictitious combinations can be also at the end of the list, their position is not relevant); n is the number of load cases (and of fictitious combinations), m is the number of true combinations.

	load case 1	load case 2	...	load case n
combi 1(fictitious)	1	0	...	0
combi 2 (fictitious)	0	1	...	0
...	...	...	...	...
combi n (fictitious)	0	0	0	1
combi n+1 (true)	desired factors for each load case
combi n+2 (true)
...
combi n+m (true)

Combinations are added to the active Combi Set in Sargon/ CSE. Fictious combinations will not be selected and so they will not be used in CSE checks.

Note that STRAP does not print applied loads in the report; only results are available (see below).

b)Local orientation conversion from STRAP to Sargon/CSE depends on user's choice about major axis definition in STRAP. See the following conversion cases:

b.Spring direction must be specified in global reference system, i.e. node system in spring definition must be 0.

c.For each stiffness not null, a spring (rotational or translational) is added in CSE/Sargon.

Connection codes are not supported by STRAP, and it was not possible to use conventions to make Sargon/CSE able to assign needed connection codes (as done for SAP2000, for example, where conventional groups define connection codes on beam elements extremes). For this reason, user possibly needs to define connection codes in CSE after the model has been imported from STRAP and before JNODES are searched for. If end releases are left unchanged and only connection codes are added, this operation does not imply a loss of results, so imported results will be still available after connection codes definition. We recall here briefly that connection codes are useful when more elements meet in a node without any end release: connection codes will mark the elements which will be interrupted and connected, while element with no connection code will remain unmodified and will therefore be the "master" of the connection.

As already mentioned if results of the STRAP analysis are available, the import routine can create the binary files with the results in the Sargon/ CSE format. The following are imported:

3.All internal forces at beams extremes in all load cases and combinations (at the extremes only, since internal forces along beam axis are not printed in STRAP report.

4.Currently, the stresses for two-dimensional and solid elements are not imported and are therefore null.

Since some information about the model are missing in STRAP's output report, user may need to modify the model before jnodes search: connection codes may be added to some elements to avoid cuspidal or tangential jnodes, different materials may be assigned to different elements, etc. All these operations can be done without losing the results. Note also that cross-sections can be changed (for example if a section is not in the conversion file, so replaced with a dummy one).