A shock absorber — often just called a "shock" — is a mechanical apparatus whose primary purpose is to cushion movements and impacts. It is often found in automobiles, where it is used to provide a smoother ride. In construction, a shock absorber is commonly called a damper. It serves as a safety measure to help minimize a structure's movement caused by natural forces such as strong winds and earthquakes.
Shock absorbers work by absorbing excess kinetic energy usually resulting from sudden or strong movement. The kinetic energy is then discharged by storing or transforming it into another form of energy. Absorption and dissipation of energy varies depending on the type of shock absorber used.
Objects like spring coils tend to bend or compress whenever excessive stress is put on them. During compression, energy is transferred to the material. A hysteresis shock absorber utilizes this effect by using materials that can retain their shape after absorbing tremendous energy. The disks found in the spinal column work in the same principle as a hysteresis shock absorber.
Friction type shock absorbers use a material's natural resistance to reduce energy. Shock absorbers of this type are usually called dashpots. The manufacturing industry frequently uses dashpots to lessen equipment vibration. This is commonly done to reduce the wear and tear on the machine. Shock proof gadgets also usually have some form of friction shock absorbers to prevent damage when they are dropped.
Hydraulic and gas shock absorbers use fluids, like hydraulic oil and air, contained in a cylinder to absorb energy. Outside force causes a piston on top of the cylinder to push on the fluid. Tiny perforations on the cylinder bottom then allow a small amount of fluid to pass through. Letting fluid flow out of the cylinder prevents too much pressure from accumulating and ensures smoother recoil.
Car shock absorbers normally integrate both spring and hydraulic shocks. They form the suspension that connects the chassis to the body of the car. By using two types of shocks, the suspension more effectively lessens the shakes experienced by the passenger.
The stiffness of the suspension is typically adjusted depending on the desired level of control. A soft suspension emphasizes on a comfortable ride, while a hard suspension usually gives a more responsive handling. Race cars often have different stiffness settings between the front and rear shock absorbers. The front suspension is normally tuned for faster turning. The rear suspension, on the other hand, is calibrated for increased traction.