Category Archives: Maths

The roof of the Taq-i-Kisra; Analysis

Posted on 10/06/2008 by dougaj4

Following the previous post, I have compared the stresses in the Taq-i-Kisra assuming either a catenary or parabolic profile. I have also compared constant depth sections with sections increasing in depth towards the supports. The arch span was taken as … Continue reading →

Posted in Arch structures, Finite Element Analysis, Maths, Newton | Tagged , , , , , | 2 Comments

Elegant Proofs – 1

Posted on 18/05/2008 by dougaj4

Roger Penrose in his book “The Road to Reality” gives a remarkably simple proof of Pythagoras’ Theorem: Drawing a perpendicular to the hypotenuse from the right angle (line CD) will divide any right angled triangle into two similar triangles, both … Continue reading →

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Evaluate Function

Posted on 22/04/2008 by dougaj4

It would often be convenient to evaluate a function entered as text; for instance if we have the function for the deflection of a cantilever under point loading at the end: F*L^3/(3*E*I) then it would be convenient to be able … Continue reading →

Posted in Excel, Maths, UDFs | Tagged , , | 9 Comments

Section Properties of Defined Shapes – Spreadsheet

Posted on 25/03/2008 by dougaj4

Download section properties spreadsheet from: http://www.interactiveds.com.au/software/Section%20Properties03.zip http://www.interactiveds.com.au/software/Section%20Properties07.zip Section properties for 35 defined shapes Section properties from coordinates Section properties UDF Screen shots:

Posted in Excel, Maths, UDFs | Tagged | 29 Comments

Section Properties from Layers

Posted on 19/03/2008 by dougaj4

An alternative to finding the section properties of irregular polygons from the coordinates of the corners is to divide the shape into rectangular or trapezoidal layers.  The properties of the shape may then be found by simply summing the properties … Continue reading →

Posted in Maths, Newton, Uncategorized | Tagged , , , , | 1 Comment