Can strain exist without deflection?

[wasif]

Lets take an example of a person pushing a thick wall, of course no deflection in the line of action of force is seen but can strains be induced in it, like surface slips?

 

[Doug Huffman]

The definition of strain is dL/L. Stress less than some limit should cause no strain.

 

[Chestermiller]

Lets take an example of a person pushing a thick wall, of course no deflection in the line of action of force is seen but can strains be induced in it, like surface slips?

What are surface slips?

Chet

 

[Chestermiller]

The definition of strain is dL/L. Stress less than some limit should cause no strain.

This is not correct. Any stress will cause a strain. But, if the stress is very low, the strain might not be significant.

Chet

 

[ltkach2015]

via wikiapedia: http://en.wikipedia.org/wiki/Deflection_(engineering), http://en.wikipedia.org/wiki/Deformation_(mechanics),

I believe you can have a displacement at the line of action even in a thick wall. Unless there is some sort of rigid constraint that prevents that.

deflection is the degree to which a structural element is displaced under a load. It may refer to an angle or a distance.

strain is a normalized measure of deformation representing the displacement between particles in the body relative to a reference length.

So, I think it depends on the constraints. Otherwise there will be a strain under any deflection, no matter how small. Check out my picture it may help.

 

[tdev]

strain will be induced due to its own weight also.So,strain will always be present.

 

[wasif]

What are surface slips?

Chet

Hi chet, thanks for the reply

Surface slips by which i mean the deformation of the slip planes at the surface if the force is just enough.