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# Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

## Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

(OP)
G'day All

I expect & hope some of you in this forum has the knowledge of the work of Wang&Rose. My question is regarding the article 'A crack bridging model for bonded plates subjected to
tension and bending'by Wang&Rose 1998.

Wand&Rose presented two methods for estimating the stress intensity factor of asymmetric bonded repair : (1) Kirchhoff-Poisson plate bending theory (geometric linear), and (2) Reissner|s plate theory (geometric non-linear).

Following the procedure (Eq. 36) for the simpler case in (1)/geometric linear, and the numerical examples, I am not getting the same presented results (I missing something, and hope your comments help me to figure out). Also, following the presented procedure and examples (Please see attached,summarized example with the procedur)
in my results,

Both the membrane stress intensity factor & the bending stress intensity factor are functions of both (bending and membrane stress) opposite to the presented results in the abovementioned article: membrane & bending stress intensity factors are functions of the membrane stress only and bending stress only, respectively.

Apart from the magnitude values, the membrane stress intensity factor was always > the bending stress intensity factor whereas the presented results in Table(1) & Figure 6 were the opposites.

Have you ever solved or run into a paper where the presented examples in the above paper was solved/with some details!
Do you have any suggestions or comment on the procedure I followed introduced in the attached, please?

Please accept my apologies if you find the question does not fit or should not be here

Thanks

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

Wazy,

First off I don't have that paper so it is kind of hard to follow along with your work.

Is this for a metal-to-metal structural bonded repair with a crack in the repaired layer, or is it for a bonded composite patch? I was going to point out some other papers but this will make a difference.

One thing you might try to do is look for SIF publications which have referenced this paper. They might work through the solution in some other specific context.

Maybe I'll hunt for your paper if I have time this weekend.

Keep em' Flying
//Fight Corrosion!

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

(OP)
LiftDivergence

Yes, This model for a metal bonded with a composite patch. in Wang&Rose 1998 paper, they presented an example for a cracked aluminum component reinforced with
boron/epoxy patches.

I already went through most of the papers that cited the abovementioned work of Wang&Rose but unfortunately was not helpful to overcome the difficulty in solving the numerical equations or regenerate their results.
I tried to summarize the presented procedure of the paper in the attached file in the original post, but I agree having a look at the paper will be helpful.

I should emphasize that Wang&Rose presented a very clear procedure to solve SIF in tension and bending. The solution for SIFs is to solve a set of linear equations. Following this procedure, I did not succeed in getting the same published results. I missing something maybe the way to construct these equations even though they look very simple (linear)to solve.

Thanks

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

Having in the past used Rose's model for in plane loading I suggest that you check the nomenclature. I have not seen the paper to which you refer, but I do know that in the past Rose has used a nomenclature whereby the plate is of thickness 2t and the total load applied is 2P/ In other words, the model is based on half the actual plate thickness and half the load. Caused me so much stress I changed his equations to use actual loads and actual plate thickness.

Not sure if this the issue with your calculations, but I hope it helps.

PS I know both Francis and John personally and could help you get in contact with at least John Wang.

Regards

Blakmax

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

(OP)
Blakmax,

Thank you so much for your comments & kind offer to help.

The nomenclature might be one reason but in the paper, I am working on ((1), more detailed in (2)), it seems no issue with (thickness&load nomenclature)but still there few nomenclator issues in some parts of the paper. So this point is one of my concerns. One way to check is to repeat the derivation of the mathematical procedure but it was not easy as the mathematical background of the model(solving the hyper-singular Integral equation)is very advanced and time-consuming.

If you can help me by connecting me with one of them (Chun-Hui Wang, Francis Rose) will be so much appreciated. I did not try to contact them yet understanding how much busy they would be to go back to that paper and check for me. As you know them, I think it would be possible we get an answer.

Could you please advise me with a way to contact them (contact them through you (emailing you first), or you notify them and then I contact them)

(2)Chapter7 in Advances in the Bonded Composite Repair of Metallic Aircraft Structure)Link

Thanks & Regards

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

It is an unfortunate aspect of this forum is that it is not possible to post email addresses without being admonished by the moderators (understandable) but also that it is not possible to post private messages to other forum members. I personally think that is a pity because many issues are best resolved off line. I suggest that you try googling Defence Science and Technology Group (note the real way to spell Defence) and then try "contact us" to see if they can put you in contact with John Wang. Tell him Blakmax sent you.

If that doesn't work, contact me4 again, maybe through Adhesion Associates.

Regards

Blakmax

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

(OP)
Blakmax,
Thank you for following up
I agree with you, it would be much helpful if there is a way that the forum members can contact each other, but that unfortunate for now.

I will give it try to contact the DSTG. Hopefully being a PhD-student would sound reasonable reason that they provide me with his email.

However, I feel I should double check with you that 'Wang' that worked with Francies Rose on developing the crack bridging model (SIF in bonded plates under combined tension and bending) is "Chun-Hui Wang"
but I guess you know John Wang works in this area as well and he can help. Am I correct?

Thanks&Regards

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

I believe that Chun Wang and John Wang are the same person. I know that he and LRF Rose collaborated on bonded repair technology. I suggest you contact DSTG through their website, and ask them to pass on your message to Wang. (I believe that Frances may have retired.)

All the best Blakmax

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

(OP)
Blakmax,

That's sound great! I will contact them soon and will come back to you for the update.
Thanks&Regards

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

That was my next suggestion.

Best wishes

Max Davis

### RE: Crack-Bridging model for bonded plates (tension+bending)-Wang&Rose 1999

(OP)
Max Davis
I have just recognized you with your name. It is so kind of you the help and sharing your distinguished experiences here. Thanks a lot.
I am a Ph.D. student in my last year(Civil/Monash). Hope will be a chance to meet you in person in the near future may be a conference.
Now, I'm so confident to contact CH Wang.
Kind Regards

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