Practical Composites Stress Analysis - Training and Useful References 1

[stm6602]

Hi Everyone, we're looking for some Practical Composites Stress Analysis Training Courses and Reference materials. Most of our stress analysts are familiar with metallic airframe analysis, and the kind of strength checks required, varying from hand analysis to FEA, as well as Damage Tolerance Evaluation. However, with the introduction of more and more composites primary structures in some of the latest commercial aircraft, it has rekindled the interest to develop practical stress analysis techniques for composites structures. By "practical", we're looking for training courses that are being taught by practising engineers and useful rules of thumbs practised by the aircraft structures community.

In addition, if anyone is aware of useful reference book on Composite Stress Analysis, similar to what we have for metallic structures, e.g Bruhn's, Flabel or Niu, your advice will be greatly appreciated by all. Thanks.

 

[rb1957]

Niu's book on Composites

 

[KirbyWan]

Boeing training and flight services (formerly Alteon a Boeing company) provides a composite course. here are the details:

http://www.alteontraining.com/training/coursedetails.aspx?id=1938

There is also an advanced course:

http://www.alteontraining.com/training/coursedetails.aspx?id=1948

If your Engineers have gone through the sructural repair for engineers courses then they know what to expect. I have not been through any of these yet, but there are plans to send me and I'm excited to go.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[SAITAETGrad]

Baker- Composite Materials for Aircraft
Gay-Hao- Composite Materials: Design and Applications

 

[SAITAETGrad]

Also, NAFEMS has an FE for composites course coming up:

http://www.nafems.org/events/nafems/2010/el012/

 

[midsidenode]

I came across those Alteon tranining courses that Kirby mentions a couple years ago. Although they appear very compelling, i've never attended them. If anyone has any report on them - i'd love to hear it. As for the Niu book, it's very good. Although it has very little material that can be considered as guidance for conducting strength analysis on composites, it's contents are really a must for understanding composite technology. Niu offers a class to go along with the book. I've not attended it either but i've spoken to some Boeing friends who have and they've said very positive things about it. Our engineers have obtained all of our training thru abaris. They are very highly respected for this type of training. I'd recommend you check them out at the link

http://www.abaris.com/

 

[bf109g]

Ditto on Abaris. Very good training - start with the laminated plate course.

The Boeing training is a little wishy washy. Keep in mind it's designed for airline repair engineers and light on the design side.

 

[ESPcomposites]

Great question. I ultimately decided there was nothing comparable to Bruhn, Niu, or Flabel for composites. Therefore I decided to create a book that is truly practical and modeled after Flabel's, but it is still a ways out.

My best suggestion would be Niu's composite book from a practical standpoint, though it lacks substantiation in many areas. From a mechanics standpoint, I like Jone's or Daniel and Ishai's book. You can read some additional reviews on books and popular papers on my website.



Brian

http://www.espcomposites.com

 

[moon161]

Haven't had a chance to use it, but my courses in uni were taught out or PK Malik's book.

http://www.amazon.com/Fiber-reinforced-Composites-Dekker-Mechanical-Engineering/dp/0824790316

 

[ESPcomposites]

I have not reviewed this book, but if it was taught at the university, there is a good chance it may not reflect many practical techniques.

The academic approach usually focuses on laminated plate theory and lamina based failure criterion. In practice, open holes, bolted holes, compression after impact, etc. often size structure. University courses usually does not address this, or may just touch on it.

I think the problem is that academia likes "exact" solutions and with "strict" mathematics. In reality, there is a lot of grey area when dealing with composites. That does not suit academia well since it a more "universal" approach is desired.

This is also why each major company has a different philosophy, though the underlying physics and mechanics are largely the same.

This is based on working at 3 major aerospace companies and also teaching a graduate level composites course.

Brian

http://www.espcomposites.com

 

[SAITAETGrad]

I'm surprised that nobody has mentioned two of my favourites:

Gay-Hoa-Tsai

http://www.amazon.com/Composite-Mat...=sr_1_1?ie=UTF8&s=books&qid=1280641885&sr=8-1

Baker

http://www.amazon.com/Composite-Mat...=sr_1_1?s=books&ie=UTF8&qid=1280641969&sr=1-1

 

[ESPcomposites]

I have the second edition of the Gay/Hoa book and just looked it over. While it does make some attempts at practicality, I don't see it as an equivalent to Bruhn, Niu, Flabel.

I didn't see any significant mention of holes, joints, compression after impact, etc. Topics like stability, radius opening, stress concentrations, are also very important that are not addressed. But I will take a deeper dive and see what gems it might offer.

From viewing the contents of the Baker book, I like what I see. I will pick it up soon, thanks for mentioning it.

Touching on another point, I fail to see why more author's don't go into detail about the major differences between metallics and composites. They are treated in almost opposite fashion for static and DaDT (durability and damage tolerance). Certainly some discussion for the those making the transition would be beneficial. This is a high priority on my book development.



Brian

http://www.espcomposites.com

 

[ESPcomposites]

Just noticed that I have the first edition of the "Composite Materials for Aircraft Structures" from a borrowed collection.

I actually like the approach and it is very practical oriented compared to other books. It covers some important topics such as joints and damage tolerance. But it is more brief than I was hoping for. Nonetheless, it is supported more than Niu's book, which is largely just a series of snapshots from major works. Not that I am criticizing Niu, since identifying the right way to approach the problems is half the battle.

Just by glancing at it, it looks worthy of recommendation.

Brian

http://www.espcomposites.com

 

[WKTaylor]

Some useful references... beyond those already mentioned above...

SAE AIR 4844B Composites and Metal Bonding Glossary

SAE AIR 4938 Composite and Bonded Structure Technician/Specialist: Training Document

SAE AIR 5278 Composite and Bonded Structure Engineers: Training Document

SAE AIR 5279 Composite and Bonded Structure Inspector: Training Document

SAE AIR 5719 Teaching Points for an Awareness Class on "Critical Issues in Composite Maintenance and Repair

SAE ARP 4916 Masking and Cleaning of Epoxy and Polyester Matrix Thermosetting Composite Materials

SAE ARP 4977 Drying of Thermosetting Composite Materials

SAE ARP 4991A Core Restoration of Thermosetting Composite Components

SAE ARP 5089 Composite Repair NDT/NDI Handbook

SAE ARP 5143 Vacuum Bagging of Thermosetting Composite Repairs

SAE ARP 5144 Heat Application for Thermosetting Resin Curing

SAE ARP 5256 Mixing Resins, Adhesives and Potting Compounds

SAE ARP 5319 Impregnation of Dry Fabric and Ply Lay-Up

SAE ARP 5605 Solid Composite Laminate NDI Reference Standards

SAE ARP 5606 Composite Honeycomb NDI Reference Standards

USAF T.O. 1-1-690 GENERAL ADVANCED COMPOSITE REPAIR PROCESSES MANUAL

MIL-HDBK-17-1/-2/-3** [several]

MIL-HDBK-23 STRUCTURAL SANDWICH COMPOSITES [canceled, but some good general info]

MIL-HDBK-731 NONDESTRUCTIVE TESTING METHODS OF COMPOSITE MATERIALS - THERMOGRAPHY

MIL-HDBK-732A NONDESTRUCTIVE TESTING METHODS OF COMPOSITE MATERIALS ACOUSTIC EMISSION

MIL-HDBK-733 NONDESTRUCTIVE TESTING METHODS OF COMPOSITE MATERIALS - RADIOGRAPHY

MIL-HDBK-787 NONDESTRUCTIVE TESTING METHODS OF COMPOSITE MATERIALS-ULTRASONIC

MIL-HDBK-793 NONDESTRUCTIVE TESTING TECHNIQUES FOR STRUCTURAL COMPOSITES

MIL-HDBK-803 GLASS REINFORCED PLASTICS PREVENTIVE MAINTENANCE AND REPAIR

MIL-STD-1944 POLYMER MATRIX COMPOSITES [canceled, but some good general info]

Care and Repair of Advanced Composites, Second Edition
AUTHOR(S): William Cole ISBN: 978-0-7680-1062-6 Published: June 2005 [SAE]

Design of Durable, Repairable, and Maintainable Aircraft Composites AUTHOR(S):
ISBN: 978-0-7680-0020-7 Published: August 1997 [SAE]

Composite Materials for Aircraft Structures, Second Edition, Revised
A. A. Baker, Defence Science and Technology Organisation S. Dutton, Cooperative Ctr for Advanced Composite Structures D. Kelly, University of New South Wales ISBN-10: 1-56347-540-5 ISBN-13: 978-1-56347-540-5 [AIAA]


Regards, Wil Taylor

 

[SAITAETGrad]

ESP,

With Regards to Gay-Hao-Tsai,

Chapter 6: Joining and Assembly
-discrete joints, holes, and stress concentrations.

Section 5.4.5 very briefly discusses delamination in compression after impact, damage tolerance.

Appendix 2 includes figures for buckling of orthotropic structures with the caveat that stability is not in the book's scope.

Overall, the focus of the book is more as a primer in analysis of orthotropic structures, working with laminates, and analysis of typical sandwich structures with some practical information and some leads on more advanced topics.

For someone (such as myself) who who comes from the sheet metal world, it is a very good primer as it focuses on the topics most unfamiliar in a brief and easy to understand manner.

 

[ESPcomposites]

Although there is a chapter dedicated to joints, it is as brief (and with questionable results), as I have seen. I think MIL-HDBK-17 or even some publicly available papers by Hart-Smith would offer far better information. As far as the delamination section goes, it is very brief. I kind of like the curves presented in Appendix 2, but it would be nice if there was some substantiation like in Jones' book.

As far as what the OP was talking about though (Bruhn, Niu, Flabel equivalents), I just think this is quite far off. However, as a newcomer to composites, with limited options there is some value there. Probably not on my short list though. Though you say it is a primer, engineers simply must be properly introduced to these very important topics if they are going to use composites with confidence. Niu's book does at least touch on these subjects with more depth.

Also, thanks for the reminder about the needs of those making a transition. It must be gradual at first and not overcomplicated. Especially in the professional environment where engineers want solutions, not mathematics.

Everyone has their favorite books, I certainly have mine. So this is just an opinion. I really commend any author willing to spend the time to tackle such a challenging topic. I am finding just how difficult it is and it is impossible to please everyone.

Brian

http://www.espcomposites.com