ULS Design Functions – update for AS 3600

Posted on 28/05/2019 by dougaj4

The ULS Design Functions spreadsheet (last posted here) has been updated to the new Australian Standard for concrete structures; AS 3600-2018.  The new version can be downloaded from:

ULS Design Functions.zip

Note that the biaxial version included in the download zip file is not yet updated for the new code.

The interaction diagrams below compare the new code with results from the previous version, which generates the same results as the 2017 version of the bridge code (AS 5100):

With 32 MPa concrete the new code generates higher results where bending controls (because the reduction factor is increased from 0.8 to 0.85), but where compression controls the capacity is reduced, if the reduction factor of 0.6 is applied.

Under some conditions the new code allows the reduction factor for compression to be increased to 0.65.  The higher reduction factor is applied in conjunction with the 100 MPa concrete in the screen shot below (click image for full size view):

In this case the new code gives significantly higher results over the full range of axial loads:

The new version also has a number of other recent updates as shown below:

Posted in Beam Bending, Concrete, Excel, Newton, UDFs, VBA | Tagged , , , , , , , | 3 Comments

Working with dynamic arrays in Excel

Posted on 23/05/2019 by dougaj4

Many of the VBA functions available here return results as arrays, which must be entered by selecting the desired output range, then  pressing Ctrl-Shift-Enter (CSE).  This can be inconvenient (or at least untidy) when the size of the output array varies.  Some solutions to this, using VBA and/or Python were presented  here.  Microsoft have also been working on this, and for members of the Windows Insider  Program, dynamic arrays have been available for some time now.  Dynamic array formulas are entered as standard single cell formulas, but automatically resize to display the entire array (or “SPILL” if the output range contains any existing data).

The new dynamic arrays (currently only available in the Excel Insider version) have potential problems when spreadsheets created in an Insider version are opened in earlier versions.  Charles Williams at Fast Excel has been investigating these problems, and has recently published a detailed review of potential problems, including a free CheckDA tool that allows you to check that the workbook you create using Excel DA will not cause problems when opened in prior Excel versions.

 

Posted in Arrays, Excel, UDFs, VBA | Tagged , , , , , | Leave a comment

The Barrow Poets

Posted on 11/05/2019 by dougaj4

The Barrow Poets  (according to this site) started out selling poems from barrows in the late 1950s, then moved into performing in pubs.  I saw them performing in London, probably in 1972.  In spite of their undoubted originality and creativity, it seems they are not worthy of a place on Wikipedia, but here is one person’s  version of their story, followed by some samples of their musical poetry  (or is it poetic music?):

I first encountered the fabulous Gerard Benson in the very early 1970s when the Barrow Poets played in a scrubby basement in the Sir Christopher Wren pub in the old Paternoster Square, by St Paul’s Cathedral in London, when I was barely old enough to buy a (legal) drink. While other young things were into Genesis or King Crimson, I was gripped by their spectrum of poetry and music, from their own compositions to Purcell, Byrd, Blake, Keats, Stevie Smith and lots of Anon.

With the endlessly energetic Gerard, small and roundish, reciting, singing and playing kazoo and saw, the visually contrasting William Bealby-Wright, tall and thin and slightly lugubrious, on the homemade cacofiddle – once described in the Guardian as “a kind of DIY, cymbal-augmented double bass, seemingly built by the Clangers” – and the other wonderful musicians and poets, they were electrifying. Later they played in grand venues such as the Royal Festival Hall, but nothing could match the immediacy of the basement bar…

More at ‘Gerard Benson and the Barrow Poets were electrifying’

Posted in Bach | Tagged , , , , | 1 Comment

How Reinforced Earth works

Posted on 08/05/2019 by dougaj4

“Reinforced Earth” is the name of  a construction system widely used in retaining walls around the World.  Here is a short video demonstrating how the system works, which is both informative and entertaining:

Posted in Newton | Tagged , , , | 1 Comment

RC Design Functions 8_03

Posted on 30/04/2019 by dougaj4

The RC Design Functions 8_03 spreadsheet is now available for free download from:

RC Design Functions8.zip

The main changes are:

  • The NA layer check has been corrected for compression steel in tension
  • The new AS 3600 crack width and curvature methods have been added to the Circe function
  • The AS 3600 formula for crack width has been corrected for the effect of shrinkage.
Posted in Beam Bending, Concrete, Excel, Newton, UDFs, VBA | Tagged , , , , , , , | 11 Comments