Medeek Engineering

[Medeek]

I have posted frequently on the various extensions that I create within SketchUp to augment and automate SketchUp.  Some of this geometry can also be brought into Chief where the Chief user does not want to be bothered with modeling intricate timber trusses etc...

I am also working on various engineering tools that will work directly inside of SketchUp.  The tools will be useful for the residential designer and architect to run quick numbers on various things like posts and beams.  I am currently focused on developing a beam analysis tool that will facilitate these sorts of engineering tasks.  At some point I may also offering engineering consulting for an additional fee, but that is yet to be determined.

Here is the latest status on the development of the upcoming beam engineering tool:

 

I am currently working on a beam analysis tool for analyzing (wood) beams within my Wall extension. It's taken a couple weeks to cobble together the matrix analysis engine but it is slowing emerging.

Now that I have the shear, moment, slope and deflections algorithms in place for point loads it is just a matter of algebraically adding multiple loads for more complex loading scenarios (ie. multiple loads and factored load cases). Here is a very simple example of two point loads applied to a two span beam. Note that self weight of the beam is not yet being considered:

I need to add some formatting logic into the top beam diagram to account for shorter spans so the dimensions don’t run into the supports as shown. This is why a lot of testing and debugging is necessary.

This beam engineering tool with its matrix analysis engine is probably the single most complicated piece of code I’ve ever written, it certainly rivals the truss calculator (2013) and the complex roof (2019) module. I will admit that I now freely use ChatGPT with some of my coding puzzles lately and surprisingly it even understands the context of what I’m coding and offers suggestions to improve the accuracy and efficiency of the engine itself.

The numerical integration (for the slope and deflection) was initially stymied by incorrect boundary condition constants and I had no easy way of analytically solving for them. At that point I was fully aware of the issue but I was stumped at how to arrive at the right solution. ChatGPT suggested a normalization algorithm which proved to be correct and was even an easy fix within the algorithm. It’s like having a really smart graduate student looking over your shoulder pointing out what your doing wrong and how to make it all better.
 

[Medeek]

I’ve been wanting to finish this beam calculator for some time now so I’m trying to dig deep and see if I can’t get it out the door, even if it only has the capabilities to handle wood (sawn lumber, glulam, SCL, I-Joist) beams and joists initially..

Unlike my previous web based beam calculator this new tool will be completely open ended, there will be no limit on the number of supports or loads one can assign. Each load can have up to six different load types (dead, live, live roof, snow, wind, or seismic) So in a sense it is a general solver or engine which makes it quite powerful and much more useful in my opinion.

The one other harsh reality with engineering though is that the code is always changing. I will need to continually update the tool as future revisions to the ASCE7 and NDS are released as applicable. I’ve noticed as I review various copies of the ASCE7 (2005 - 2022) that the load cases are continually changing, which I find a bit odd, you would think that after years of refining the code we would slowly arrive at suitable load combinations and stick with them. This constant flux is rather annoying to be perfectly honest, and makes me really question the powers that be and why they can’t iteratively arrive at a standard and eventually stick with it.

We all know how the (engineering) sausage is made. Why continually tweak the recipe? The technology and materials used in the building industry has not dramatically changed in my lifetime (50+ years). All of this continual tweaking and minor adjustments to the engineering code really does nothing to safety of the structure in my mind and simply adds to the cost of engineering since new software updates are required and additional training is imposed. Maybe the ASCE needs to keep itself relevant and the revenue from selling updated pricey copies of its signature standard (ASCE7) is a serious cash cow? I don’t know what the story is with all of this but I feel I need to rant a bit when I just shelled out $260.00 for a paperback book that I will only crack open once every few months at best.

 

Here is another screenshot of the calculator interface:

 

The graphics are generated using SVG within HTML. I'm formatting the HTML so it can easily be printed to a nicely formatted PDF, easier said than done.

 

 

[Medeek]

I am curious.  How do CA users currently do some quick engineering calcs for structural members in their models?  What sort of workflow is typical or maybe there is no specific or typical workflow?

[richoffan]

BeamChek 2024. Been around a long time. Inexpensive one time purchase. Constant updates. Does wood (many species) wet, repetitive member, Glulam, LVL Micros, Steel. Lets you set your own values Fb, Fc, E etc.  etc. And offers several variants to select on the calcs so you can see actual % shear, depth of deflection and so on. Does col., notches, hips, valleys.... Never let me down. Submit calcs to structural if necessary and PE just comes back with some options if we want to consider. If you could take the model, allow user introduced values (30PSF, 40PSF, linears on partitions , stone veneers, snow loads etc.) and have the model show loads, tributaries, points, reactions etc. in the model - Now that would be AMAZING!!

Edited Saturday at 10:51 PM by richoffan

[Joe_Carrick]

I use StruCalc.  It provides just about anything you can imagine and I can stamp/sign myself.

[Medeek]

First look at the shear and moment diagrams being generated by the report generator.  It took me most of yesterday and today to learn the ropes of Chart.js, an open source charting library for Javascript.  It's not perfect but it does seem to get the job done.  My only real issues with it is that I still can't figure out how to make it render to a higher resolution (300 dpi for printing purposes).  The sample below is a screenshot of the PDF that is printed from the HTML output.

 

 

 

I've used quite a few different beam checkers and software in the past.  I used to use Woodworks Sizer app and then switched to Forte and BCCalc.  I was disappointed when those last two switched from a desktop app to a web based app, but I'm sure they had their reasons.  My standard report will be quiet verbose but I can also see the need for a compact one page report, so I will probably be working on that as well in the near future.

Even though a lot of people think that only engineers use this type of software that is quite incorrect in my opinion.  Any designer or architect worth his salt should know enough about the basics so that they are able to quickly run the numbers for a beam, header, rafter or joist.  Knowing the ballpark specs of any of these members is crucial in many cases when putting together a design.

Edited yesterday at 04:59 AM by Medeek

[Medeek]

I am using the stiffness method per Ch. 15 of R.C. Hibbeler’s book, Structural Analysis. For intermediate loads between supports I use (FEM) fixed end moments. I’m actually still working on the matrix analysis piece. I’ve got point loads pretty much in place I’ve just got to implement distributed loads next. I suppose I could have it generate the entire polynomial for both shear and the moments since I am generating them for each applied load, it is probably just matter of using superposition on them as well.

Here is a first look at the ability to switch between various load cases for the deflection graph: