Mechanical design substantiation library recommendations 2

[davemechuk]

OK I've found posts something similar to this in the structure forum and realised that its littered with civil structure engineers. As most suggestions are to do with concrete, wood and foundations. Now I'm in the right place!

I'm a mechanical stress engineer in the energy industry and thus don't deal with grand structures/buildings; rather, fixtures, tooling fixtures, assemblies, lifting equipment and pressure vessels/piping; all use various materials (mostly steel).

I'm expected to perform design substantiation for the above and therefore stress/thermal analysis (hand calcs and FEA).

I am interested (and hoping) to learn of any library 'MUSTS' that engineers have with similar roles?

I've not been long graduated so for the moment mine is short and I'm hoping to build on it:

-Roarks
-Shigley
-Fundamentals in Heat and mass transfer - Frank P. Incropera

Personally I need to find a decent FEA/FEM text book, and Strength of Materials Text book.


Dave

 

[davemechuk]

I'm aware that similar request have been made (and my apologies), however, I'm trying to cater the question with regards to my particular role to get more appropriate recommendations.



Dave

 

[JohnRBaker]

Don't forget a copy of the 'Machinery's Handbook' as well as good textbook like 'Mechanics of Materials', by Higdon & Ohlsen, which will provide the basic science and math used in 'Roarks' and 'Shigley'. As far as FEA/FEM is concerned, don't forget to contact the software vendor(s) that you're dealing with as they might also be able to provide you some documents as well as training courses, at least in the use of their software. Also some of the professional organizations may provide some suggestions for continuing eduction opportunities in fundamentals of FEA. And don't forget your local universities or community colleges as you might find some opportunities there for some classes in the basics of FEA techniques.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
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To an Engineer, the glass is twice as big as it needs to be.

 

[dhengr]

Davemechuk:
What, pray tell, did you do with your text books on Engineering Mechanics, Strength of Materials, Theory of Elasticity, Thermo., Fluid Mech., Physics, etc. etc. from the Uni? I hope you didn’t trade them in for five cents on the dollar, at the end of the class. They would be the most familiar to you, as refreshers on the fundamentals, along with your class notes. Then we can all list our current favorites in each subject. There are bunch of good old standards, the bibles on their subjects, that any good engineering library should have. Those lay the groundwork on the subject, and every practitioner better know what they teach. Despite your protestations to the contrary, you will need a good foundation in structural analysis and design, along with some knowledge of metallurgy and welding to do what you are aspiring to do. Mark’s Std. Handbook for Mech. Engrs. is a good one, for a little of everything. A guy by the name of Omer Blodgett has two books in particular; “Design of Welded Structures” and “Design of Weldments,” from Lincoln Arc Welding Foundation, which would be very good to have on your shelf. Lincoln Electric has other very good books, very reasonably priced too. AISC and AWS, ASME all have codes which you’ll have to comply with.

 

[drawoh]

JohnRBaker,

As an addon to the OP, how usable do you think FEA is for structural substantiation?

I recently prepared and submitted calculations to show that an airborne system would remain intact during a survivable crash. I tried very hard to avoid FEA because I was not sure how to present the results in a verifiable, reproducible format. If I pull stuff out of Roark's, or out of my old mechanics of materials textbooks (Popov), an engineer can go through it, check my arithmetic, and decide whether or not he likes my analysis model.

The approving engineer challenged my use of tapped holes into the edges of plates. I wound up using SolidWorks Simulation to model a loose, sideways loaded screw in a tapped hole. The model was easy to build and run. Explaining and documenting it to my and his satisfaction was a challenge.

FEA is fantastic at finding vibration modes and elastic deflection. When I searched through my structure for points of possible failure, almost everything was fairly easily evaluated by textbook mechanics of materials methods.

--
JHG

 

[davemechuk]

JohnRBaker:
Thank you for those your suggestions.

Sorry, when I mean FEA its not so much on how to use it, what I mean is the theory behind it, I don't think ANSYS really publish such texts, mostly the extensive help documentation explain how to do something or am I wrong?.. Again, I've done courses on such things, I just want a book on it. I'll do some digging tomorrow to see if ANSYS have published such documents tomorrow.

dhengr:
Thank you for your comment!

A couple of people have asked what have I done with my books! I purchased two textbooks in my first year uni and it cost me a fortune (never used either of them), so I was reluctant to purchase any for my remaining years, and never had to, I used the uni library if a book was of vital importance, saved me a shiny penny! Again, my structures professor who taught us fundamentals of stress, damage tolerance, corrosion, beam element theory and FEA theory was very old school (loved paper) and so EVERYTHING was down in paper in his notes ie. he had no book suggestions for me so thus I am here.

Just to clarify I have been in work for almost two years now, spending 50% of my time doing the role above, as a graduate engineer the other 50% of my time has been moving around to other roles to build a general knowledge of the industry I am in.

Never really thought about welds, mostly I've been doing lifting equipment and our client likes to avoid welds in load paths! But I suppose eventually I will be doing more serious analysis on pressure vessels, and this will be valuable, thank you.

Dave

 

[JohnRBaker]

OK, one book that I can recommend is:

http://www.crcpress.com/product/isbn/9781439802946

DISCLAIMER: the author of this book works for Siemens PLM Software (his office is just the other side of the building from mine) and neither myself nor Siemens PLM benefits monetarily from the sale of this book.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[davemechuk]

A very good strength of materials book by Timoshenko is suggested by everyone. However, there appears to be 'modernised versions', for example:

Strength of Materials book - Timoshenko (3rd ed)
Mechanics of Materials - James M. Gere, Stephen P. Timoshenko 5th - A 'rehash' (want for a better word) of Timoshenko's original.
Mechanics of Materials - James M. Gere, Barry J. Goodno 8th - I assume this is the same book as the 5th ed but does not give recognition to Timoshenko, naughty!

I'm a bit cautious, can I really go wrong in selected any of the above? I want to get the latest (Gere/Goodno) as it is easier on the eye (not a big fan of typescript), but these modern ones tend to be filled with 'clutter' for students.


Dave

 

[rotw]

Applied Finite Element Analysis
Larry J. Segerlind

 

[KLee777]

Pressure Vessel Handbook by Eugene Megyesy.

 

[SNORGY]

davemechuk,

If your client does not like welds in load paths, what is his position on things like lifting lugs for vessels or tow rails for skids? As an engineer in the energy industry, such a client will make it difficult for you or anyone else to build anything. Well, they can build it; they just might not be able to move it.

I am kind of old school. I wouldn't put a lot of time and attention into FEA in your line of work - YET. There are some standard software packages that will be of benefit to you: CAESAR II, S-FRAME, other structural programs, perhaps. On the piping side of things, I favor L.C. Peng's book. For structural issues, I always seem to fall back on Benham & Warnock, as cryptic as it is. For most other general mechanics of materials issues, Roark's is very good.

For general heat transfer, I really like J.P. Holman's textbook. For heat transfer specific to exchangers, I like Kearns.

Maybe it's just me, but despite the fact I am not as good at it any more as I used to be, indeed, as I feel I ought to be, I believe that if you can use a pencil, a ruler, an eraser, a pad of calculation paper and a reasonably good scientific calculator in conjunction with textbooks and Industry Codes, Guidelines and Recommended Practices, you will end up being better off than one who relies too heavily on software. That said, in order to provide solutions at the pace demanded today, the requirement to become proficient with analysis software is becoming inescapable, especially for younger folks getting into the field. We gray-haired plodders can still duck it, since the expectation of us is that we are there just to provide guidance, checks and balances (mentorship), but software skills are now becoming important. I just think that without the "plug and chug" approach to build a background in the subject matter, the software will be of no benefit.

 

[IRstuff]

I think that your concern about FEA equations is unfounded, so long as you are using a relatively recent, and commonly used, FEA package. I've never seen in any design review any questions relating to what equations are used in FEA. It would almost be like someone asking for how Excel implements its trig functions. Hopefully, no one seriously believes that the simulations are exact replicas of the real world. All simulations are abstractions of the total system, even Roark's or other famous equations/correlations.

That's not to say to ignore hand calculations; they should go hand in hand. FEA, by virtual of its parallel calculations, can theoretically model MORE of a system than a hand calculation. But, a hand calculation is often necessary to verify that everything modeled in the FEA, and the FEA itself, is behaving correctly.


TTFN
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[JohnRBaker]

Hand calculations can also be used as a 'sanity check' to make sure that you're even in the right ballpark.

And while we're on the subject, it's a shame that so little emphasis is being placed today on doing quick estimating before accepting the answers that the automated tools are giving people. Back in the days of slide rules, you had to have a certain ability to do a quick approximation, if for no other reason than to know that you're within an order of magnitude (i.e. you have the number of decimal places correct) of where the answer should be. When calculators, with their 6+ places of 'accuracy' came along, some people just assumed that there was no longer any need to do those mental approximations. It's becoming a lost art.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[davemechuk]

SNORGY

Having no welds does not remove the ability of something to move. Most lifting equipment can be designed ensuring load paths travel through sections, fasteners, etc. We were designing some one off lifting equipment, of course the off the shelf slings and RHS use seemless welds, however, he didn't want welds in the rest of the desin I believe because in this line industry such equipment require a lot more paperwork and testing, and it wasn't particularly high-tech lifting equipment.

And to say not use FEA yet?!... Its just a tool, as long as you know how to use it (as discussed here by others) its as powerful has the person who holds it, as with many other tools. Each tool for its own appropriate task. I'd be silly not learn how to use it and how it works, not only for engineering purposes, but for self-marketing. Note that I do if anything lean more to hand calcs, i just see the value of both capabilities.

Dave

 

[SNORGY]

davemechuk,

So, now I understand (sorry if I missed it) that you are primarily concerned with the lifting equipment itself, as opposed to the equipment being lifted? In that case, you are correct, you can design things to keep welds out of the load path. My more narrow-minded bias focused me on the equipment being lifted. Apologies.

With respect to not using FEA "yet", again, my bias towards considering the equipment being lifted (i.e., the objects of the lift) probably drives that, whereas if your focus is on the machine doing the lifting, FEA probably becomes much more appropriate. Again, apologies.

 

[davemechuk]

Oh you were referring to FEA with regards to lifting equipment... sorry I wasn't clear, I have not used FEA on any lifting equipment so far... as yes its fairly simple to substantiate the designs, I use it for other complex shaped products.

Appreciate your book suggestions though! And again a thank you to everyone, a lot of help!!

Dave