effects of size and speed on model airplane crashes

I am looking for an equation that correlates material failure and collision speed;
so that I can better understand the effects of size and speed on model airplane crashes.

Is there an equation that correlates an object's length and speed to material failure,
for one-dimensional elastic collision of into a rigid barrier,
given elastic modulus and specific strength?

This is a guess:

specific strength :: speed^2 * length

but it's probably more complicated than that.

Thank you.