Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

5 Thanks for responses (Granite's Modulus of Elasticity)

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Thanky you all kindly for your helps.

Kasey Hemmatyar, P. Eng. (structural)
Vancouver, B.C. 
_____________________message separator________________
At 10:28 AM 4/28/98 +1000, you wrote:
>Dear K Hemmatyar,
>
>The Young's modulus is the intrinsic property of an undamaged material.  It
>is constant.  Usually measured between teh 15 to 85 percentile results in a
>tension or compression test.  The closure of micro cracks will cause a
>higher E in compression that is now handled in Damage mechanics with a h
>value of 0.2 to 0.3 
>ie multiply tensil E by this to get compressive.
>
>The Young's modulus for Salem sandstone is in the order of 25 to 50 Giga
>Pascals (sorry i never learnt English Units I'm from Aussie land.)
>
>I have recently measured E for bricks at a range of 5 to 55 GPa.  This range
>is for same bricks in some cases.  Natural materials even manufactured
>bricks are not linearly elastic as exactly as Hooke's Law would suggest.
>
>The Modulus of Elasticity is a measurement of teh Young's Modulus at a
>particular point in time and sapce after material has been subject to
>loading.  It is only the same for purely ealstic materials or undamaged
>materials.
>
>One measures E on a representative sample  For granite your are probably
>looking at the same as concrete about a 100 mm cubed to get a continuum
>measurmement
>
>If you are using the results remember
>Micro results are effected by the test method so they may be high.
>
>Meso results apply to small areas like an area beneath a building.  In hte
>modelling I do at this scale I allow an E of about 10-20 GPa.  The material
>is goiong to be cracked and splintered.  Your problem is what you are using
>the modelling for if it is for a dynamic analysis of a building I would use
>10 to 20.
>
>If it is for a material to be used in a building I would get it measured at
>a good lab.  I would send it to Abrams in Urbana.  If you are using mortar
>in between it will have an E of 1 GPa tops.  This will affect the results
>depending on the thickness of the two materials.  DAvidge book on ceramics
>has a formula to solve this problem I can send it to you if you like.
>
>Failing that I would ask the Coloroda School of Mines I think thats it.
>Actually I would ask them anyway.
>
>John Nichols
>
>I trust this helps.
>
>F
>seaoc(--nospam--at)seaoc.org,Internet writes:
>1.   Does any one know what is the Granite's Modulus of elasticity (roughly)
>or where can I get it? (it is Sunday!)
>
>2.   Question: Modulus of Elastisity and Young's Modulus is the same but
>does "Modulus of Rupture" refer to the same property?
>
>Thanks 
>
>K. Hemmatyar, P. Eng. (structural)
>Vancouver, B.C. 
>
>
>Reference "SOIL MECHANICS" by Lambe and Whitman
>
>Modulus of elasticity ranges from 10.6 to 12.5 x 10^6 psi
>
>Modulus of rupture os a different property.  I can't find it in a text but if
>you recall for concrete modulus of elasticity is 57,000*SQRT(f'c) and modulus
>of rupture is 7.5*SQRT(f'c)
>
>
>__________________________________________________
>
>Richard Lewis, P.E.
>Missionary TECH Team
>rlewis(--nospam--at)techteam.org
>
>The service mission like-minded Christian organizations
>may turn to for technical assistance and know-how.
>
>