A hydraulic shock absorber dissipates mechanical energy by forcing fluid through restricted valve passages. This calculator defines a selected linear viscous reference from an entered force at 0.5 m/s; it does not predict a real damper's nonlinear force curve, temperature or rating.
Selected Linear Damper Reference
Explore a selected linear damping reference with a connected monotube piston, oil chambers and floating gas separator.
Equation Used
- Force is proportional to the magnitude of selected piston speed.
- The reference coefficient is constant.
- The displayed piston motion is illustrative and freezes at zero speed.
- Nonlinear valves, temperature, gas pressure, friction, loads, durability and safety are excluded.
The entered force at 0.5 m/s defines the linear reference coefficient; it is not a product rating.
Connected monotube schematic
The rod enters through a seal and drives the working piston inside one tube. Oil flows through the piston valves in opposite directions during compression and rebound. A floating separator keeps the gas apart from the oil and moves to accommodate the volume of the entering rod. With incompressible oil, separator travel equals rod travel multiplied by the rod-to-bore area ratio. The illustration uses a diameter ratio of 0.30, giving an area ratio of 0.09. Playback stops at zero selected speed.
What the calculator determines
The selected reference force F₀.₅ defines c = F₀.₅/0.5. At selected speed v, the ideal linear reference is F = cv and instantaneous dissipation is P = Fv = cv².
Selected linear reference
c = F₀.₅/(0.5 m/s); F = cv; P = Fv = cv².
Selected-input arithmetic
For F₀.₅ = 1,200 N and v = 0.5 m/s, c = 2,400 N·s/m, F = 1,200 N and P = 600 W.
Not a damper design or rating
Real dampers can be asymmetric in compression/rebound and strongly nonlinear with velocity, displacement, temperature and valve state. This reference excludes gas pressure, cavitation, seal friction, hysteresis, heat capacity, fade, stroke limits, mounts, loads, durability and vehicle dynamics.
Questions
Is c a measured product coefficient?
No; it is defined by the entered reference point.
Is all power instantly removed as heat?
P is the ideal instantaneous mechanical dissipation rate in this selected model.
Does the animation size a shock absorber?
No.
Primary technical references
BILSTEIN: Shock absorber failure analysis — monotube working piston, oil flow, gas separator and rod-volume compensation.
- Monroe, Shocks vs. Struts — manufacturer explanation that hydraulic shock absorbers convert suspension-motion energy into heat and that resistance depends on piston speed and valve/orifice design.
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