I'm designing a machine to test a static object (I'll refer to it as A)'s resistance to deflection due to impact force.
This design uses a pneumatic(probably wont be using hydraulic) cylinder to apply the impact force to the surface of A. (However, if I were to use the pneumatic cylinder alone to apply the force, I would have to position the surface right at the end of the piston stroke. If I allowed the piston stroke to be slightly more than the distance between the two to completely apply the force on the surface(overexerting the cylinder), I will damage the cylinder over time and reduce its lifespan.)
Hence, I added an extended head to the piston end with the use of springs and linear guides(shafts) within it. In my head, I picture it as the head exerting the impact force(F) first at a pretty high speed and then when the head stops at the surface of A the springs absorb the remaining of the piston stroke.
However, I have some concerns too so I'm hoping some of you more experienced and knowledgable people out there can help.
- Since the speed is moving at a pretty fast speed(completes the stroke(completely extends) in 1 second), would the head be able to totally transfer the force F from the cylinder piston to the surface of A or would the springs somewhat absorb the force and lower the resultant output force? How should I select springs for this purpose?
- To determine the force of the cylinder, use Force = mass * acceleration. The thing is, I have the equivalent load mass(60kg) but I don't have the acceleration. I only have the distance(stroke length = 300mm) and maximum piston velocity(300mm/s). Since the velocity is pretty fast and stroke length is not that long, how should I calculate the acceleration? Can I assume that the acceleration will be constant since the piston will extend completely pretty fast?
- The cylinder applies a force equivalent to a 60kg load. How should I be calculating the output? In terms of force, F=ma or kinetic energy, 1/2*m(v^2)? Since there will be spring energy in play as well(?)