why does ASTM C393/C393M not contain a maximum deflection formula?

[melixman2016]

Hello,
why does ASTM C393/C393M not contain a maximum deflection formula?
it may be that it's due to standard version?
my samples are tested under standard ASTM C393/C393M
Should I get the equation out of any other book?

Thank you

 

[RPstress]

This standard is for measuring "core shear properties", none of which in these tests are affected by deflection. In the real world you keep an eye on through-thickness Brazier stresses in core but even they are not affected by deflection. If you want deflection to make sure a test fixture has enough clearance (or something) work deflections out from engineers theory of bending and add on the deflection due to shear (shear is not included in ETB). A reference such as Roark should give adequate help.

 

[SWComposites]

What are you trying to obtain from the test? And why do you need a defection formula? Deflection can be measured directly if you need it for some reason.

C393 is a short beam test, for core properties, and the defection will be a combination of bending and shear deformation.

 

[melixman2016]

Thank you for your valuable reply.
I want to maintain the flexural strength of a sandwich
we have already tested Kern alone and received the shear modulus.
I chose the wrong standard?
There is also other standard D7249/D7249M, but it is for surface course and long beams.
our sample can be maximum 180 mm long.