Frame4.xls – Update2

Posted on 31/12/2009 by dougaj4

It was recently pointed out to me that the Frame4 spreadsheet was giving an overflow error with a fairly small analysis.  The problem turned out to be that the analysis did not have any restraint specified in the X direction, resulting in a division by zero.

I have now added a check of restraints to ensure that there is at least one node restrained in each of the X and Y directions.

The modified spreadsheet can be downloaded from Frame4.zip

Link to the original Frame4 post: Frame Analysis with Excel – 7; Shear deflections and support displacements

Posted in Excel, Finite Element Analysis, Frame Analysis, Newton, VBA | Tagged , , , | 12 Comments

Distributing Silverfrost Fortran Applications

Posted on 28/12/2009 by dougaj4

Earlier posts have included User Defined Functions (UDFs) linked to Fortran dll files compiled with Silverfrost Personal Fortran:

Solving simultaneous equations – Fortran dll

Trigonometric Functions – dll

Linking Excel to Fortran – 2

Transferring these files to a new computer it came to my notice that if the Silverfrost compiler is not installed it is necessary to install the file SALFLIBC.DLL in the same directory as the dll files (usually Windows/System32).

See this Silverfrost Forum post for more details.

The required file can now be downloaded from: Salflibc.zip 

Alternatively install the Silverfrost Personal Fortran Compiler (free for personal and evaluation use).

Anyone still having problems with the Fortran UDF files after installing the Salflibc.dll file, or the entire compiler, please leave a message.

Posted in Excel, Link to dll, UDFs, VBA | Tagged , , , , , | 2 Comments

Just in Time for Christmas!

Posted on 21/12/2009 by dougaj4

The new version of the Australian Standard Concrete Structures Code (AS 3600) has just made it for 2009:

Download from SAI Global

Posted in Concrete, Newton | Tagged , , | Leave a comment

Cubic Spline Update

Posted on 16/12/2009 by dougaj4

The previous post in this series presented a User Defined Function (UDF) to fit  a cubic spline to a series of points defined by XY coordinates.  Each segment of the resulting spline is defined by a separate cubic curve, which may be easily integrated to find the area under the curve.  The UDF CSArea() has been added to the cubic spline spreadsheet to perform this function.  The spreadsheet may be downloaded from: CSpline2.zip  As usual, the spreadsheet includes full open source code. 

The screenshot below provides additional detail of the area calculation, and an example finding the area of a semi-circle: 

CSArea Function example, Click for full size view

Posted in Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , | 1 Comment

The Ambassadors

Posted on 13/12/2009 by dougaj4

The Ambassadors (1533) is a painting by Hans Holbein the Younger in the National Gallery, London. As well as being a double portrait, the painting contains a still life of several meticulously rendered objects, the meaning of which is the cause of much debate. It is also a much-cited example of anamorphosis in painting.

The Ambassadors

The astronomical instruments on the top shelf are shown in greater detail here:

Click to see full size

The instrument on the right is a torquetum

The small instrument in the middle front is a multi-faced sundial

Any suggestions for the other instruments?

Update:  A detailed article about the instruments in the painting from the Journal of the Royal Astronomical Society of Canada

Posted in Newton | Tagged , , | 1 Comment