Eng-Tips is the largest forum for Engineering Professionals on the Internet.

Members share and learn making Eng-Tips Forums the best source of engineering information on the Internet!

  • Congratulations dmapguru on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Conversation starter: How heavily do you rely on computational tools?

human909

Structural
Joined
Mar 19, 2018
Messages
2,295
Location
AU
Conversation starter: How heavily do you rely on software computational tools?



In a effort to start an interesting conversation.... How heavily do you lean on computational tools. To help aid the discussion I'll try to break up the tools into categories in order of computationsal complexity: (I'm attempting to define groupings here, if things clearly don't fit feel free to let me know and I'll adjust...)
  1. 3D FEA either in 3D bodies or 3D shells (including BUCKLING ANALYSIS)
  2. 3D FEA either in 3D bodies or 3D shells
  3. 3D analysis with 1D elements (eg; typical structural analysis programs where elements are defined as lines (columns/beams) in 3D space)
    1. Member design via software
    2. Member design via hand calcs or similar
  4. EXCEL or similar calculative spreadsheets/software.
  5. HAND calcs (calculator allowed)


 
I do mostly residential work and I put an entire project in one workbook. I haven't published hand calcs in more than 15 years.
I'm curious what your workflow would look like if you did not have to submit calcs.
 
For general construction engineering:
3.2: 30% (RISA with MathCAD design calcs)
4: 65% (MathCAD base file with some excel as standard spreadsheets or when post-processing data)
5: 5% verifications of the above

For specialized bridge projects:
2: 15% (MIDAS, mostly to get staged construction and effects of skew/curvature, not for the 3D elements)
3.2: 60% (RISA and MIDAS)
4: 20%
5: 5%
 
1. 5% - IdeaStatica for some funky connections
2. 0% - (One could argue most of my IdeaStatica use is this)
3. 50% - RISA and PLS-Pole
4. 45% - Excel
5. 0% - I use my calculator every day to check stuff or when doing quick computations when modeling, but not in the sense of doing hand calcs on paper.
 
My default is to use typical widely available design software, they are typically FEA due to the the software authors choices, but for the work I do, they do not strictly need to be FEA.

For non-typical situations where I will do the calc 5 or more times over the next few years, I will prep an entire example problem via a handwritten paper solution, with commentary explaining any derivations that are non-obvious, and write up a solution in a compile-able language (C++,C#, python if I hate myself). If I am feeling really energetic, I'll also include a methodology document, but that tends to take more time to write than the actual solution, but it also helps you to get back in the mindset if you've let the tool alone for a year+ and you need to remember how anything works.
 
For various reasons, I have, and likely always will, hate using Excel. So I default to using a compiled language rather than trying to decipher what various cell references are trying to indicate in any one of the archaic spreadsheets that are out there. I also do not have a personal excel license, so I cannot typically continue work on a home machine if desired.
 
Last edited:
I'd've said aero is 50% 1 and 50% 4 ... in my experience there is a lot of hand cranking after the FEA has had it's go.

And then of course 50% testing ... all primary structures are tested at some point.
 
I'm curious what compiler/editor combination you use for C++.
I don't write in C++ as much as I used to back in college, but I still do it from time to time if I am feeling there is a particularly good reason to do so. Working in OpenGL was the last significant work I did in C++, is OpenGL even still around anymore? Seems I could be dating myself. To answer your question, I honestly just use visual studio community. It works well for what I need it for, I like the git integrations, and I haven't spent much time branching out to other IDE's to see if there are any features that it's missing.
 
Pretty 50/50 between 4 (excel) and 5 (hand). That said, in my mind when you are using a company excel sheet or something written by a coworker, that is a separate category of "I hope this excel sheet formula was written correctly and gives good results". However, when I am using an excel sheet that I have written myself, in my mind I basically see it as a hand calc, it is just in excel format as to make life easier and more consistent for repeat calculations.
 
When I was working in it about 5 years ago or so, it was because OpenGL was open source and licensing was free (maybe only for non-commercial? I cannot recall), rather than something like DirectX, or the alternate Vulcan, which I was unfamiliar with. I was doing some work visualizing large scale spatial modeling using LIDAR datasets into an interactive 3d model in userspace, and I certainly did not want to build my own rendering pipeline.
 
I think there is a huge overlap between the categories. In particular Excel might be used for anything from category 1 through to 5. There is also still a large place for 2D analysis, especially for soil-structure interaction problems, and non-linear materials analysis should also be on the list.

My work almost always includes some FEA, mostly 2D with non-linear materials and modelling of the construction sequence. Non-linear geometric effects are included if the deflections are significant. Excel is nearly always used for generation of FEA input and analysis of the results, member design and generation of design output summary information (tabular and graphic).

"Hand calcs" if required (for instance for an independent check of FEA results or spreadsheet output) are always done in Excel. I have a calculator somewhere, but I don't remember the last time I used it, and I don't even know where it is now.

The spreadsheets use VBA extensively, but these days that is progressively being replaced with Python, mainly because of access to libraries like Scipy, and because having the code separate from the spreadsheets makes control and security a lot easier.
 
I'm curious what your workflow would look like if you did not have to submit calcs.
ive practiced in areas where you need to submit calcs, and where you dont.



Where calcs need be submitted:
  • takes more time (to format nicely and present calcs)
  • there is pressure to calculate things that otherwise you could just judge as OK by inspection.
  • there are peer reviewers snooping around having a pick at your work from time to time, killing profitability
  • often times the peer review ends up being a de-facto training session (their benefit, your cost)
  • generally there is less "working in silo" effect - work is being reviewed a lot more.
  • cost of all this is higher.

Where no calcs need be submitted:
  • engineering judgement skills become much sharper
  • cost is lesser
  • more "engineer in silo" effect
  • more time is spent looking at the drawings vs packaging a nice tidy report for someone else to read.
  • adequate documentation of work can be a chore, and it can get sloppy easily.
I prefer not having to submit calcs, myself.
 
I personally would hate to submit "proper" calcs. In Australia things seem all a bit upside down (pun not intentional).

I can design the structures for large industrial facility and never get asked for calcs or sign-offs. Yet if I design a lintel for a house the local council and building surveyor will want "calcs". Though they are satisfied with you handing over gibberish computer output. It makes no sense. 🙃

I've largely focussed my work on niche industrial stuff where sign-offs might be required but all they are chasing is somebody to take responsibility. Which is fair. I make sure I get paid for the risk and responsibility I am taking on.

My clients do good work, but when curly questions regarding complex structures come up they don't have the expertise, qualifications or risk appetite. So I step in and provide a design and take responsibility.


One of the biggest upsides that I see in my future career path, is simply the declining number of people prepared to own something and take responsibility. Maybe it is just the culture down here. But there seems to be a big reduction over a generation in an ability or desire for people to take responsibility an ownership of something.
 
Last edited:
One of the biggest upsides that I see in my future career path, is simply the declining number of people prepared to own something and take responsibility. Maybe it is just the culture down here. But there seems to be a big reduction over a generation in an ability or desire for people to take responsibility an ownership of something.

Probably something to do with the cost of PI insurance going through the roof in recent years.

Regarding requirements for "calcs" in Australia, my experience (mainly in transport and mining related structures) is that the standard requirement is for a "design report", consisting of:
  1. Details of design inputs and design scope.
  2. Summary of calculation procedures.
  3. Details of design outputs.
So no detailed calculations required. The reviewers do their own calculations, to confirm that they get the same end result as detailed in the report, which seems to me a more rational way of doing things than working line by line through detailed calculations.
 
Engineer for a structural steel fabricator

#4: 80% Excel
#5: 20% Hand calcs

When I started to lead projects, my reliance on modern technical analysis went way down. It seems like the need for detailed analysis pops up when I've missed something early-on in the project planning phase and need to cover my ass.

Sometimes my engineering approaches caveman levels. For example, how do we get a thick box column to handle thousands of kips from multiple directions and bracing? I could do an intricate analysis and spend hours crafting an elegant solution...... or I could call the project manager and check the lead time on delivery of a big ol' forged block of steel (roughly 11 weeks last I checked).
 
One of the biggest upsides that I see in my future career path, is simply the declining number of people prepared to own something and take responsibility. Maybe it is just the culture down here. But there seems to be a big reduction over a generation in an ability or desire for people to take responsibility an ownership of something.
Who would? If one would learn HTML, CSS and a bit of Java script, in three years or less one could be building web pages, make more money than a structural engineer and work anywhere in the world. This is true whether you are 18 years old, 40 years old and maybe 50 years old. The worst thing that could happen? A web site crashes. No biggie.
 
Engineer for a glazing contractor:
  1. 0%
  2. 5% (Honestly so infrequent that a good portion of that is FEAing something simple just so I don't forget how to use the software)
  3. RISA/MEPLA - 15%
  4. Mathcad - 80%
  5. 0%
I used to work for an engineering firm and did much more FEA there, partly because I liked the software they had and partly because I was justifying other peoples' designs that were tight enough that simpler but more conservative analysis approaches sometimes didn't work out. Now that I do the design work myself and don't have access to FEA software I like, I try to make my life easy.
 
I'm curious what your workflow would look like if you did not have to submit calcs.
Occasionally, I propose on a project and, when I describe my workflow to the customer, s/he responds saying they are not going to pull a permit, thus no calculations are required. My response is that my workflow is the same either way.

Also, I believe I wouldn't be as successful. If calcs weren't required, just about anyone could do what I do. If I just step across the state line from California to Arizona or IRC compliant structures, one could prepare plans for a 3,000 SF single family residence, even two story, without calcs or a stamp. Of course, most of the architecture isn't as demanding, the working environment isn't as litigous, and earthquakes aren't as prevalent. I've told family and friends, if I left California, I would have to go to work at a large firm and be part of an assembly line designing boxes all day, day after day. The Eagles song is right! I checked out a long time ago, but I am still here! The way it is now, I go to work when I want, quit when I want, can wear short pants and a t shirt most of the time and choose what projects I work on and usually do because of the entertainment value, not solely based on compensation. Of course, I work at least half a day every day when I'm not on vacation.

I really don't understand the aversion to doing calcs. It's the basic skill that we learn in college and it is the skill that separates us from others (e.g, architects) in my field. I enjoy doing calcs. I enjoy putting an entire building in a single workbook, linking area loads to joists and beams, linking beams to columns and linking columns to footings. My biggest regret is few people get to see (or appreciate in my wife's case) my work. Even after all this time, I still enjoy coming up with a better way to do things. It's also why I won't retire until I have to. I still have my statics/dynamics book from college, but I only took statics in my undergraduate program. It's one of the few hard bound books I own. I vowed a long time ago I would go through the dynamics section when I retire. That's still part of the plan, I just don't know when that will be, since I want to work as long as I can mentally. But then, if I lose the mental capacity to study dynamics, have I just created the dreaded infinite do loop? I should probably toss the book.
 
I really don't understand the aversion to doing calcs.
For me, it is mostly financial. My throughput is significantly higher without creating written calcs suitable for others to review. At least half or my projects are performed simply using my calculator without a pencil ever hitting the paper. I can charge the same either way.
 

Part and Inventory Search

Sponsor

Back
Top