I'm sure your way of doing it is way cooler than what we do in my unbelievably boring Solid Mechanics labs Are you laying gauges? I've help lay more than one or two gauges on concrete specimens. We just use lasers. Can measure the stress, strain, and lamb waves if you find either stress or strain, the other is pretty damn easy to get no clue what a lamb wave is though It is very possible to find strain and have no stress. Think of the edge of a plate being stretched in one direction... how can there be strain but no stress? They're proportionally related through Young's Modulus.