Wednesday 14 January 2015

EngineLT revised to Current Wind Code

A revised version of my EngineLT application for estimating size of frames for doubly pitched moment frames, typically used in cold-formed sheds. The orginal version was written in Delphi 3 to AS1170.2:1989, the current version is written in vb.net to AS1170.2:2011. The change in language is because I use MS Excel for day to day calculations, with schTechLIB.xla in the background providing functions for wind loading, steel, cold-formed steel, and timber design. This is written in vba and kept up to date, whilst the Delphi code not kept up to date: to avoid translating languages moved over to vb.net.

The revised version of the code reads an XML data file, this file contains names of structural sections and the resistance to bending (phi.Ms) in units of kNm. The file can be added to if needed, it already contains, Cee's, RHS, SHS, UB, UC, PFC's.

It doesn't contain back to back Cee's, such are not really required. As far as the program is concerned the bay spacing is the load width of the individual portal frame. The load width of a frame can be found by halving the distance to each frame either side of the selected frame and summing. For cold-formed steel sheds with frames at 3m centres the load width of a typical frame is 3m. The load width of the end frame is 1.5m. Often for sheds made from hot rolled steel the typical frames are UB's with the end frames made from PFC's: not always practical has it hinders extending the building, and there is extra detailing merely for two frames. Any case it gives the basic idea, the internal frames can be I-sections formed from back to back Cee's and the end frame can be a single Cee.  Knowing that a single Cee has a load width of 3m, then back to back Cee's form a frame with a total load width of 6m, the back-to-back frames can therefore be placed at 6m centres, whilst a single Cee can be used for the end frame. Therefore check frame for load width of 3m (bayspace = 3m) for a single Cee rather than the back-to-back Cee's at 6m centres.

It is also to be noted that whilst a given section may be structurally strong enough, it may not be practical to make an adequate moment connection between the rafter and column.: such check is not made by the application. Other issues not checked are the deflections of the frame.

The prime purpose of the application is to determine what is not suitable and reject immediately, whilst that considered suitable by the application requires further structural design.

To keep the input form simple, there are many assumptions made in the background. The assessment made by the application will not match my height/span charts as I adopted internal pressure coefficients of -0.65 and +0.7 for this application, but -0.3 and +0.4 for the charts.

I have a larger Engine application, which I am in the process of also translating from Delphi to vb.net and from AS1170.2:1989 to AS1170.2:2011, makes fewer assumptions but has more input screens and requires connection to a database of section properties, it also generates scripts (.scr) for AutoCAD LT. The original purpose of EngineLT was to severe the original programme from the Borland Database Engine (BDE), as it seemed far too complicated setting up on some other computer.

The application can be obtained here: vbEngineLT.zip


Revisions:

  1. [14/01/2015] Original
  2. [23/04/2016] Changed downlinks to MiScion Pty Ltd web Store

Simple Wind Loading Application: Speeds, Pressures and Pressure Coefficients

A simple application for getting wind speeds, pressures and pressure coefficients to AS1170.2 for a rectangular enclosed building with doubly pitched roof. There are two versions in the zip file download. tstwnd.exe and windyworkBench.exe. The former was written in Delphi 3 to AS1170.2:1989, whilst the latter is written in vb.net to AS1170.2:2011.

Application can be down loaded: windWorkBench.zip

Revisions:
[14/01/2015] Original
[23/04/2016] Changed download links to MiScion Pty Ltd Web Store.

Import XML Data to MS Excel

Simple Excel Application which reads the XML file created by earlier application. The data is read into the workbook, and written to a single worksheet. It is also separated into worksheets for parameters, variables, lists and tables. Lists are written across a row. Named ranges are also created for Parameters and Variables.

It doesn't use any XML library to read the file, instead it uses a limited parser written in vba.

Its a simple experimental application showing possibility of exporting and importing parameters to simple XML files, to share data between spreadsheet applications.

Normally I try to create spreadsheets with all parameters on a single worksheet, formatted to be compatible with export to DBase, Paradox and MS Access tables, such worksheet could also be directly exported to XML. However as workbooks grow, not all parameters get referenced on the summary sheet. The two XML workbooks help clean the workbooks up.

Spreadsheet can be down loaded: importXML.xls

Revisions:
[14/01/2015] Original
[23/04/2016] Changed download links to MiScion Pty Ltd Web Store

Export MS Excel named Ranges to XML

A simple MS Excel application which allows opening another MS Excel workbook and then saves all the named ranges to an XML file.  Whilst Excel permits saving workbook as an XML file, or exporting data to an XML file, such is of little use for data randomly scattered throughout the workbook.

The application exports the data tagged as parameters, variables, lists and tables. If a named range is a single cell and unprotected then it tags it as a parameter. If the single cell is not unprotected then it is tagged as a variable. A named range which consists of a single row or column of data is tagged a list, whilst a named range comprising of rows and columns is tagged a table.

It doesn't use any XML library, it simply writes the data to a simple text file with appropriate tags. Also it uses FileSystem objects to write to the file, as the standard vba print statements do not recognise unicode characters, where as Excel cells can contain such.

Spreadsheet can be down loaded: exportNamedToXML.xls



Revisions:
[14/01/2015] Original
[23/04/2016] Changed download links to MiScion Pty Ltd Web Store