ULS Design Functions – Python version

Posted on 02/04/2023 by dougaj4

I have now converted my ULS Design Functions spreadsheet (last presented here) to Python. The new spreadsheet and open source Python code can be downloaded from:

py_ULS Design Functions

The spreadsheet has the same functionality as the VBA version, providing ULS analysis of any reinforced concrete section divided into trapezoidal layers, to Australian codes, Eurocode 2, and ACI 318. It also has the added functionality of design for shear (currently to Australian codes only), and a function allowing simplified input for rectangular sections.

Input is in the same format as the VBA version, with the optional addition of shear data input where required (click any image for full-size view):

Note that for shear design:

  • The design shear force and torsion, and the associated bending moment must be entered in the range D5:F5.
  • For any hollow or non-rectangular section, or a section with prestressing ducts, the effective web width must be entered in cell F8.
  • For box sections the additional data in range T44:T47 is required.

The tendon angle entered in cell F9 is currently only used for shear design.

Output is also in similar format, with the addition of shear related results:

The py_UmomR function has simplified input for rectangular sections with two layers of reinforcement:

Posted in Beam Bending, Concrete, Excel, Link to Python, Newton, PyXLL, UDFs | Tagged , , , , , , , , , , , , | 3 Comments

Downloads update

Posted on 19/03/2023 by dougaj4

A list of files available for free download can be found under the Downloads link at the top of the page:

The list has now been updated and there are now 189 files available for download, most with open source VBA and/or Python code.

The list is in Excel worksheet format, and can be displayed in full-screen view by clicking on the icon in the bottom-right corner:

The list can be sorted by any of the columns, and has hyperlinks to download the file (Column A) and to the latest blog post featuring the file (Column B):

Note that the linked blog posts also have download links, but those from early 2019 or before will often be in http: format (rather than https:), which will not work with modern browsers. In that case just return to the download list, where all the links should work.

Posted in Computing - general, Excel | Tagged , , , , , , | Leave a comment

A not so easy problem

Posted on 12/03/2023 by dougaj4

A seemingly simple problem was posted in my Quora feed:

or to put it more mathematically, what three positive integers satisfy the equation:

It turns out the answer is not so simple. A full and detailed derivation can be found at:

Alon Amit

Checking the results is not so simple either. The values have up to 80 digits, which is way beyond the standard precision available in Excel, but using the Python mpmath library, with the EvalU spreadsheet, it can be done. Enter the three values as text (or copy and paste!), enter the formula, set the number of significant figures to 85 or more, and use the mp_Eval function:

Changing the last digit of one of the values confirms that the evaluation is working to the required precision:

The spreadsheet can be downloaded from:

EvalU.zip

For more details see: Pint MPmath and implied units

Posted in Excel, Link to Python, Maths, Newton, PyXLL, UDFs | Tagged , , , , | 1 Comment

Displaying You-tube transcripts

Posted on 09/03/2023 by dougaj4

This is probably widely known, but I only found out this week.

I find You-tube informative videos frustrating because you have to sit through 10-20 minutes of video to get maybe 1-2 minutes worth of information. If only you could display a transcript of the spoken words!

Well it turns out you can:

Click on the three dots below the bottom right corner of the video, and select “show transcript”

… and the transcript is displayed to the right. You can then click on the three vertical dots to the top-right of the transcript and select toggle time-stamp.

You can then read the transcript on-line, or select and copy to a word-processor or text editor.

Here is the video featured above:

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ULS Design Functions 2.16

Posted on 25/02/2023 by dougaj4

The ULS Design Spreadsheet has now been updated to Version 2.16, which can be downloaded from:

ULS Design Functions

The main new feature is the option to design for prestress loads applied to circular tanks. Due to axi-symmetric effects, when circumferential prestress is applied to a circular tank structure this generates a uniform axial stress across the cross section, in spite of the eccentric position of the prestress cables. This is handled by applying a virtual reaction moment, equal and opposite to the moment due to the eccentricity of the prestress. Use of this feature is illustrated in the screenshots below (click any image for full-size view):

If the “Adjust for circular tank loading” is set to “False”, or left blank, the section capacity is calculated in the usual way, allowing for the eccentricity of the prestress force:

If the option is set to True, the virtual moment is applied to the section, reducing the section capacity:

The correction for the circular tank effect is shown in the function output:

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