Category Archives: VBA

The hole through the middle of the Earth – revised transit time

Posted on 08/07/2010 by dougaj4

In the previous post in this series I produced a table of acceleration due to gravity against depth from surface, based on the four layers of the Earth (Crust, Mantle, Outer Core, Inner Core), assuming a constant density for each layer.  … Continue reading →

Posted in Differential Equations, Excel, Newton, UDFs, VBA | Tagged , , , , | 3 Comments

Update to CHSplineA Function

Posted on 07/07/2010 by dougaj4

I have recently corrected the CHSplineA function included in the CSpline2 spreadsheet.  The earlier version was returning incorrect values for the slope and curvature of the spline (with output option 2), if the spacing of the points defining the spline … Continue reading →

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Beam on Elastic Foundations Analysis

Posted on 06/07/2010 by dougaj4

A previous post on laterally loaded piles used a finite difference analysis to analyse the deflections and forces in a vertical pile subject to a lateral load at the top.  An alternative approach to the same problem is presented in “Programming the Finite … Continue reading →

Posted in Excel, Finite Element Analysis, Geotechnical Engineering, Newton, UDFs, VBA | Tagged , , , , | 6 Comments

AlgLib Spline function update

Posted on 30/06/2010 by dougaj4

Following a question at the AlgLib Forum I have added the Hermite spline fit function to the AL-Spline-Matrix collection. The revised spreadsheet, with full open source code is available for download in 2007/20010 version and pre-2007 version. Typical output of the … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , | 5 Comments

More on buckling columns

Posted on 27/06/2010 by dougaj4

Coincidentally, at about the same time as I wrote about column buckling for a column with a point load on the end, Autar Kaw at The Numerical Methods Guy was writing about buckling of columns under self weight, using the theory of … Continue reading →

Posted in AlgLib, Beam Bending, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 1 Comment