Author Archives: dougaj4

Beam geometric non-linear effects

A quick and convenient way to allow for the effect of deformations on the behaviour of beams and columns under axial load is to adjust the beam stiffness matrix, so that the calculated deflections are in equilibrium with the applied … Continue reading

Posted in Beam Bending, Excel, Finite Element Analysis, Frame Analysis, Newton, UDFs, VBA | Tagged , , , , , , | 2 Comments

Frame Analysis Resources

I recently discovered: Matrix Structural Analysis, 2nd Edition, by McGuire, Gallagher, and Ziemian. which is available for free download: Description The aims of the first edition of Matrix Structural Analysis were to place proper emphasis on the methods of matrix … Continue reading

Posted in Finite Element Analysis, Frame Analysis, Newton | Tagged , , | 1 Comment

xlwSciPy update for Python 3

The xlwSciPy spreadsheet allows a wide variety of the science and maths functions in the Python Numpy and Scipy libraries to be called directly from Excel.  The spreadsheet has now been updated for use with Python 3.  The spreadsheet and … Continue reading

Posted in Coordinate Geometry, Differential Equations, Excel, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, Python Pandas, UDFs, VBA, xlwings | Tagged , , , , , , | Leave a comment

Jørn Utzon and David Moore

Tomorrow (9th April 2018) is the centenary of the birth of Jørn Utzon, the architect of the Sydney Opera House, which is celebrated in an article at the Sydney-Morning Herald. The article quotes a grand-son of Utson, Mika Utzon Popov, … Continue reading

Posted in Arch structures, Bach, Newton | Tagged , , , | Leave a comment

Two sources of perpetual motion

The buttered cat phenomenon: The pulling-yourself-up-by-your-boot-straps technique:

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Plotting Charts With Gaps …

“How do you get VB6 to initialize doubles with +infinity, -infinity and NaN”… and various sorts of Not a Number. Back in 2012 (When is an xy chart not an xy chart) I concluded that it was not possible to … Continue reading

Posted in Arrays, Charts, Charts, Excel, UDFs, VBA | Tagged , , , | 5 Comments

More circle fitting options with Scipy

A comment on the first post on this topic found that the method used did not work well for short arcs of large radius circles.  An example of the problem can be seen in the screen shots below: The function … Continue reading

Posted in Coordinate Geometry, Curve fitting, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , | Leave a comment