How to Calculate Impact Energy for an Industrial Shock Absorber
Use moving mass and impact velocity to estimate the kinetic energy that the absorber must handle per cycle.
Direct answer
For a moving mass, the base impact energy is kinetic energy: E = 1/2 x m x v^2. If gravity or an external drive force continues acting during the stopping stroke, add or subtract that work before comparing the result with the absorber energy-per-cycle rating.
Questions this page answers
- How do I calculate shock absorber impact energy?
- What is energy per cycle for an industrial shock absorber?
- How do mass and velocity affect shock absorber size?
Required inputs
Formula logic
Kinetic energy
m is moving mass in kg and v is impact velocity in m/s. The result is the base energy to absorb per impact.
E = 1/2 x m x v^2Unit: N m
External-force work
F is drive force in N and s is stopping stroke in m. Add this when the drive keeps pushing into the stop.
W = F x sUnit: N m
Calculation steps
- 1
Calculate base kinetic energy
Use moving mass and impact velocity to calculate the energy carried by the moving object.
- 2
Add drive or gravity work
Add pneumatic, motor, external-force or gravity work when those forces assist the impact.
- 3
Compare with catalog energy rating
Select a model whose energy-per-cycle capacity is above the calculated requirement with margin.
Common mistakes
- Treating weight and mass as the same unit.
- Using average speed instead of impact speed at the stop.
- Forgetting that velocity is squared, so a small speed increase can require a much larger absorber.
Catalog source notes
- The full product catalog tables use energy per cycle (Nm/C) as a primary product rating across EK, EN, EI and ED families.
Move from answer to model shortlist.
Use the sizing tool when you have the inputs, or send the application data for engineering review.