Engineering Calculation Presentation
Engineering Calculation Presentation
(OP)
I am a Design Engineering Manager of a company that designs bespoke machinery
Recently I have been given sets of calculations to check that were difficult to understand.
Mathematically they were correct however their presentation was not in a methodical sequence for example there was no distinction between the type of stress bending or shear.
These are things that I do automatically without thinking. I have searched the internet for guides for best practice and have been unable to find any. The kind of think I envisage is a "Style Guide" for calculations. Various books have part of a chapter devoted to the topic for example Wiley Engineer's Desk Reference - Wiley (1998).
Does anyone know of either a book or network resource that would be of help?
Recently I have been given sets of calculations to check that were difficult to understand.
Mathematically they were correct however their presentation was not in a methodical sequence for example there was no distinction between the type of stress bending or shear.
These are things that I do automatically without thinking. I have searched the internet for guides for best practice and have been unable to find any. The kind of think I envisage is a "Style Guide" for calculations. Various books have part of a chapter devoted to the topic for example Wiley Engineer's Desk Reference - Wiley (1998).
Does anyone know of either a book or network resource that would be of help?





RE: Engineering Calculation Presentation
I must admit I wish I had had that pummelled into me at some point, even using MathCAD I often find it quicker to start over than revisit some old worksheet.
Bear in mind there is an element of job preservation in NOT making your calculations too transparent, this has been discussed elsewhere on this site.
I'm also a bit confused - are you checking the arithmetic, checking the equations and assumptions... or checking the answer? I'd have thought the latter was the most robust, in which case you don't need to see the other guy's working at all (that's my excuse).
Cheers
Greg Locock
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RE: Engineering Calculation Presentation
Before starting such work, it would be preceeded by an objective statement.
RE: Engineering Calculation Presentation
Before computers and spreadsheets there were chart and table organization of calculations. That just dated me.
Ted
RE: Engineering Calculation Presentation
I thought checking them would be a half hour job but once I had started I realised I could not understand them. Just little details made them unreadable for example bending stress I would workout the "I" and "z" of the section, find the maximum bending moment and then work out the stress. This way you can check the "I" and "z" for realistic values then check the bending moment. In this case the stress was calculated directly with the I Z and BM substituted in to make a complicated formula (using MathCad). In the narrative no indication that it was bending and not another type of stress so the first thing I did was try and work out what the formula was supposed to calculate then expand it to see if it made sense. It was correct but took time.
Probably we need to develop our own best practice I may even have to write my own "Engineering calculations for Dummies book".
RE: Engineering Calculation Presentation
i doubt there is anything out there other than motherhood ... explain your assumptions, rationalise why they're conservative, explain your equations (how/why they apply, what geometry values you're inputing), what loadcases you're considering, ... probably something you'd see in a uni. tech. writing course.
RE: Engineering Calculation Presentation
Tobalcane
"If you avoid failure, you also avoid success."
RE: Engineering Calculation Presentation
Tobalcane
"If you avoid failure, you also avoid success."
RE: Engineering Calculation Presentation
and Hydtools, you cannot be methodical without thinking--got it!!!
RE: Engineering Calculation Presentation
RE: Engineering Calculation Presentation
http://www.motagg.com/Books
http://
RE: Engineering Calculation Presentation
I struggle with mental arithmetic or jumping lines in simplifying equations etc.
So, I have to fully right down every step in the process.
This tends to make it easy (if a bit long winded) for others to follow.
We had it drummed into us all through school to 'show your workings', most people never did it well, I had to do it just to help myself.
I agree with others about starting out with known information, a diagram, assumptions etc. For all but the most common equations state a reference/where you got it from, explain any variables etc. At school we were taught to substitute actual numeric values only at the very end, I still tend to do this.
Sometimes this is over the top, but for anything needing a record it's an absolute minimum.
KENAT,
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RE: Engineering Calculation Presentation
Here is one reference for the basics of Engineering Calculations, used in the Nuclear Regulatory environment:
http://www.efcog.org/bp/p/doc/BP65.pdf
RE: Engineering Calculation Presentation
1. clean sheets of engineering paper, and use plenty of it. I told them it was their Patriotic Duty to support the US Paper Industry.
2. clear statement of problem and clear statement of desired results (reinforced their writing / communicating skills). Use sketches and diagrams for clarity.
3. statement of known quantities
4. statement of unknown quantities
5. statement of assumptions and justifications of assumptions with quoted references if possible
6. formulaic development, with units. Use sketches and diagrams for clarity.
7. after final formulaic reduction, then final insertion of numeric quantities (with proper significant figures) and calculation of results
8. Double Check results: "does it make sense?" results, proper units, proper significant figures.
I told my students that if they did Steps 1-6 in their exams, then that was worth 80% credit. After they adopted this strategy, then their grades all improved and the panic level during exams was significantly reduced.
TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering
www.bluetechnik.com
RE: Engineering Calculation Presentation
Chris
"In this house, we obey the laws of thermodynamics." Homer Simpson
RE: Engineering Calculation Presentation
Hopefully, someone in the opensource community will come up with a simple tool for doing this type of calculation.
TTFN
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RE: Engineering Calculation Presentation
Chris
"In this house, we obey the laws of thermodynamics." Homer Simpson