Peery answer key group

[sigma38]

I’ve been trying to find an answer key for Peery’s original edition of Aircraft Structures and haven’t had any luck. I’ve been in contact with numerous DERs, professors, and even Peery’s son and daughter. None of them knew of an answer key and the general consensus was that Dr. Peery didn’t create one (at least formally).

So, as an effort to encourage a key to be created I’ve thought a peer review might be an acceptable method.

Here’s how we plan to make it happen....a private online group will be created with a limited membership of working aircraft engineers and we’ll have a forum for reviewing the book and answering the problems. My plan now is to do one chapter a month (there’s 18 chapters) and only answer the odd questions. Perhaps in a few years we can come back and answer the even ones for review. We’ll be working out of 1950 edition and will start July 1st. , 2007.

Anyone interested in going through Peery and getting a fantastic education in fundamental aircraft engineering methods please email me at removethis_sigmatero@yahoo.com

If the response is high enough then perhaps we can have some fun here.

BTW, if you don't own this book then get a copy, it's excellent.

 

[40818]

Hi sigma38, firstly, i think that most of the members here already have more than a fundamental grasp of aircraft engineering methods, as were all professionals in the industry. Forgive me if i'm wrong, but if i'm reading between the lines i would think that your post is tending towards the student side of things rather than the practicing, again if i'm wrong then i apologise.
As for the content of the post, I cant personally see the need however for an answer key for Peery, as the whole reason for deciding to set about solving the questions is to gain further understanding about the principles. What i think your trying to accomplish is to have a booklet of answers to his problems, the only way you could be certain of the answers would be to do them yourself. If a person is using his book to develop their understanding, then by following the text and examples, the answers should be easily solveable given a bit of time and effort, and the reader would know that they were correct and not need confirmation from a key guide, which is the more important aspect.

 

[sigma38]

40818…there's several reasons for wanting to create the answer key.

1. Based on quite a few posts on this list it seems that folks are hungry for textbooks on fundamental aircraft engineering stress analysis techniques. Aircraft Structures by Peery certainly fits this criteria.

2. Folks that aren’t in a hurry to go through a book but that would like to with a group of peers can use this as an opportunity for a structured method of discussion and problem solving.

3. For hotshot stress guys, perhaps even you, answering the problems should be quick and trivial. Though like most things in life it may not be as easy as it first appears and my guess is that even the most seasoned hand-calc expert will learn a bit in the process.

4. It allows professionals in the field to contribute to a good cause- supplementing a resource that helps future engineers.

5. It will be fun.

 

[40818]

sigma38...I most certainly wouldn't call my self a hot-shot, i think this whole business is like climbing a mountain, as you reach a crest and you learn something new, only to find you have far mroe to learn than you thought!!! as you see the true scale of the mountain.

Looking back in retrospect, maybe i was a little to critical of your idea, it could be viewed as an opportunity for people to learn more about the job.

As for fun, must say i'd rather play with my kids in the evening, but i do enjoy solving a problem.

Let me know how high your response is, i wouldn't be able to commit to a rigid format, but might be able to pitch in from time to time with an answer.

Regards.

 

[sigma38]

Sure, I would be happy to invite you (and others) to the discussion group. Shoot me your email address at removethis_sigmatero@yahoo.com and I'll send the details. Thanks for being open to the idea.

BTW, I was just comparing solutions for crippling of stringers and how Peery deals with flange geometry as compared to Bruhn and Flabel. I think folks will find this an interesting book review.

 

[40818]

Hi
Never really spent time comparing the diferences between methods. I generally use the gerard/needham approach, or even just .58Et(t/b)2 for the free edge if i'm feeling harsh.
Might be useful to take say a typical section and use different methods to get results, then channge the driving perameter, say thickness, width, shape etc. Seeing how they vary.
old Elmer shows a comparison on C.9 where the 2 methods are compared and give values of 37,100psi and 43,500psi, which shows how much of it is a black art rather than a science.

Havn't thought about this till now, so probably will make a fool of myself by writing before thinking....
If a local section is crippled before the whole section does or is buckled in a long wave, and therefore doesn't take anymore load, it is effectivly removed fom the allowable area for the compression stress, which will go up. Do the methods account for an immediate jump in stress which could take another individual section over the edge of instability, and so the process goes on?

Any ideas?

 

[rb1957]

i think you're right about post-crippling strength ... when an angle in isolation cripples it fails 'cause ...
1) there are no other loadpaths available for the load, and
2) there is no other strcuture available to resist the deflection (caused to be crippled angle collapsing).

In a real structure, there are probably plenty of other load paths available ... possibly the cap of the frame might cripple, causing the frame to become somewhat of a plastic hinge, but probably not directly bringing the "house of cards" falling down.

However, it is really easy to define failure as exceeding the crippling allowable, and the other approaches require a "tonne" of analysis (or deep thought) and not for a significnat gain ...