looking for "simple" plate design software 1

[logikman]

Sometime ago I found some software that checked deflection and bending stress in rectangular plates. Cannot find it now and so need to know if there is still such an animal out there ?
Requirmeents are for either 4 or 2 edge support, UDL, concentrated AND "line load" to calculate max bending stress and deflection. Application is calculating glass thicknesses for various panel sizes.
Most of the "simple" design software does not include line loads. Formula for spreadsheet OR suitable software will do

Regards

Logikman

 

[RG88]

A couple of thoughts:

You could write your own spread sheet from the formulas in Roarke's Stress and Strain.

Try

http://www.xcalcs.com,

I think they have a calc sheet for the plate loading your are considering.

I do have some concern about the glass issue, I don't think it has a typical stress-strain curve and is not an elastic material. Be careful of brittle failure before you reach your calculated defection. I would double check the elastic issue in a materials science general text.

 

[scotland6]

RG88's thoughts are well founded. As glass is a brittle material it will have a distribution in fracture strengths normally described by a Weibull distribution.

This distribution is based on sample testing of representative samples with representative loading and the spread of failure strenghts is then scaled to match the actual component being analysed. This scaling takes into account the fact that a larger area has potentially more flaws therefore will fail at lower loading.

Much info is available on the web on this subject but a good reference is 'Materials for Infrared Windows and Domes, Propertied and Performance' by Daniel C. Harris, ISBN 0819434825.

Good Luck!!

 

[logikman]

Following a major crash I lost the site information for this forum. I now have found it and can post a response to the earlier suggestions.
re: RG88's thoughts - the glass is always either toughended or laminated so it tend to act very much like a sheet of metal.Indeed it can be defelcted quite some way before it fails. eg: a 2700 x 1000 x 12mm panel in toughened glass can deflect up to 30mm with a 500N load.
I tried the xcalcs site but could not access the relevent area for some reason.
Anyway thanks for your info

re: scotland6
Thanks agian I will look up "weibull"on the web.

Ps

I still have not tracked the software I found last year so if anyone knows of anything like it please let me know.

 

[Bbird]

Logikman,

You can keep on looking but you can't find anything simpler than the tables and formulas in the book of "Formulas in Roarke's Stress and Strain". RG88's suggestion is to program the formulas to get additional information if needed (e.g. moments and deflection of interior points etc). There is another book by Szilard on bending of plates and tables there could be easier to read.

I always use them to do sanity checks on my computer analyses.

 

[Binary]

Roark has also been converted into a Mathcad electronic book...

 

[tincan]

Try "Moments and Reactions for Rectangular Plates"
*US Dept Interior/Bureau of Reclamation Engineering Nomograph No. 27. Its quite useful.

 

[Tankman650]

tincan,

Is there more information in this publication than is shown in Roarks Formulas????

Does this publication deal with large deflection analysis???

 

[Bbird]

Rudolph Szilard's book "Theory and Analysis of Plates" is quite comprehensive with tables. I expect all of the formulas and tables from different publications are comparable because they are the theoretical solutions.

 

[smcadman]

Look into MDSolids (Mechanics of Deformable Solids). It is easy to use, and pretty cheap. There is a 30 day free evaluation at:

http://www.mdsolids.com/

I dowloaded version 1.5 in 1999, and the trial demo still hasn't expired. They are now in ver. 2.6 but I am unsure if the new demo actually stops working after the specified time period.

Flores

 

[logikman]

At I last I found the PLATE analysis progamme I was looking for:
It called Analysis Group and is available as a trial download at

http://www.iesweb.com.

The only problem that it does not seem to handle is lin-loads" but most other loading conditions are covered.