Help understanding MIL-HDBK-17 tables. 2

[KirbyWan]

Howdy all,

So I've been wanting to understand the data in MIL-HDBK-17 better to use the information in a spreadsheet or perhaps update some property libraries in the spreadsheet that Abaris created, but there were several parts of the information that I don't understand.

First, to use the first table of data for T-500 12k/976 as the example, in the 'Lamina property summary' there are entries for Tension, 1-axis and 2-axis which say II-I. What is that indicating? Is the second I the 'Interim' indicated under classes of data at the bottom of the page, then what is the II telling me?

Then in the property tables for the F1,TU and epsilon1,TU there are values for C1 and C2, but I don't know what these are. I'm guessing they are coefficients that define the distribution, but I'm not a master of statistical analysis and was hoping someone could tell me if I'm right and either point me to a helpful source to understand what these mean or let me know what the really are?

Are there other sources of composite stress-strain relationships that could fully characterize lamina and laminate properties for analysis?

Thanks,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[ESPcomposites]

The MIL-HDBK-17 material data is rather old and not that useful. I think you will have better success with NCAMP (National Center for Advanced Materials). There are far more useful properties there (such as open hole and filled data for laminates). Some of the NCAMP data is incorporated in CMH-17, which replaces MIL-HDBK-17.

Brian

http://www.espcomposites.com

 

[KirbyWan]

Thanks for the NCAMP reference ESPcomposites. I just created a login and will see what information they have. Is the CMH-17 worth the $300? If it has more extensive data I may be interested and could convince my company to get it.

Best Regards,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[ESPcomposites]

Regarding material data, the source is NCAMP and CMH-17 would just incorporate some of it (but not all because of the release schedule). So if it is just material data that you are looking for, NCAMP is your best bet (it is the most exhaustive public database that I am aware of and its a big step forward). But if you want information beyond that (and further discussion regarding the nuance of the statistical aspects), CMH-17 is an updated resource compared to MIL-HDBK-17. Check the release schedule for the next update though.

Brian

http://www.espcomposites.com

 

[SWComposites]

Thre is an Intro section to CMH-17 vol 2 that explains the codes in the data tables.