Wikidata:Property proposal/compressive modulus of elasticity

compressive modulus of elasticity edit

Originally proposed at Wikidata:Property proposal/Natural science

Done: compressive modulus of elasticity (P5993) (Talk and documentation)

Description	the ratio of mechanical stress to strain in an elastic material when that material is being compressed
Represents	Young's modulus (Q2091584)
Data type	Quantity
Template parameter	This proprety request is part of the project of creating an infobox for materials
Domain	material (Q214609)
Allowed values	Any number. Qualifiers : temperature (P2076) (shall be mandatory), under pressure (P2077), determination method (P459)...
Example 1	6061 aluminium alloy (Q4641644) → 60 gigapascal (Q53448922) [1]
Example 2	copper (Q753) → 100 gigapascal (Q53448922) [2]
Example 3	brass (Q39782) → 50 gigapascal (Q53448922) [3]
Source	w:Young's modulus, [4], [5]
Planned use	Creating an infobox for materials on the french wiki (this is the first material proprety requested, others will be needed)

Motivation

For some materials, the compression modulus is different from the classical tensile Young modulus. --Thibdx (talk) 22:36, 15 October 2018 (UTC)[reply]

Discussion

Support David (talk) 07:28, 16 October 2018 (UTC)[reply]
Question If "compression modulus is different from the classical tensile Young modulus", then why is this marked as representing Young's modulus (Q2091584)? On en:wp, "Compression modulus" redirects to bulk modulus (Q900371), which already has the property bulk modulus (P5668)... Circeus (talk) 15:24, 16 October 2018 (UTC)[reply]

You raise an interesting point.

Young modulus refers to unidirectional strengh. Bulk modulus is another sort of compression modulus that refers to isostatic pressing : in all the directions at once.

There is 2 types of Young modulus : in tension and compression. The value is not always the same.

The Young modulus in tension : this is the most used one. 99% of datasheets just write "Young modulus" not precising that it has been determined with a tensile test.
The Young modulus in compression : is mostly used for material that are meant to be used in compression. i.e. concrete. Or materials that have a very different compression and tensile modulus.

There is several ways we could handle that :

Creating both the Tensile Young modulus and the Compression Young's modulus.
Maybe that we don't need a specific property this time and use a qualifier like direction (P560). I would rather avoid using a same property for different directions because as you can see here, mechanical properties are a 3 dimensional matrix and some properties have a specific name. It would not be very intuitive for contributers to guess how they should decline the property using qualifiers. It is also a problem to display it clearly in infoboxes. However since the 2 properties have the same name it may be the most intuitive this time.

--Thibdx (talk) 21:10, 16 October 2018 (UTC)[reply]

I'm not opposing (I'm not knowledgeable in physics enough to really comment further), but it does have to be accounted that "compression modulus" is apparently not used for article on any of the Wikipedia. Maybe this just needs to be name "Compression Young modulus" as a name, as you point out. Circeus (talk) 00:35, 17 October 2018 (UTC)[reply]

In order to solve this dilemma I made and extensive research in studies and datasheets.

Findings :

Many materials have a compressive modulus that is 2x or 3x the tensile modulus. So that the values are very different and not to be confused.
Materials that have both compressive and tensile modulus in the datasheet generally use 2 different sections rather than grouping all elasticity modulus in the same section.
The wording “Young’s modulus” is not common in datasheets. Most datasheets use “Tensil Modulus”, “compressive modulus” or “elasticity modulus”.

So that my proposal after having reviewed existing datasheets would be to have 2 properties :

Tensile modulus of elasticity (renaming the existing Young's Modulus property)
Compressive modulus of elasticity (renaming the current request)

Regards --Thibdx (talk) 20:01, 17 October 2018 (UTC)[reply]

Support Thanks Thibdx for sorting this out, I think it makes sense now. ArthurPSmith (talk) 17:45, 18 October 2018 (UTC)[reply]

@Thibdx, ديفيد عادل وهبة خليل 2, ArthurPSmith, Circeus: Done: compressive modulus of elasticity (P5993). − Pintoch (talk) 19:28, 24 October 2018 (UTC)[reply]