The SAN 413A device is used to study the phenomena of free and forced vibrations of a spring / mass / damper system. A carriage suspended from a spring and a dash-pot moves, guided by rollers, along two vertical guides. The mass of the truck, the stiffness of the spring, the damping of the dash pot and the excitation frequency of the system are adjustable. We measure on two sides: amplitude frequency and amplitude phase. The very simple form of the device allows students to easily observe the phenomena of free and forced vibrations. The displacements of the mass are represented graphically. The demonstrations and the experiments carried out are based on a spring mass / damper system. The vibrations are caused :
- By oscillating, at variable frequencies, the upper point of attachment of the spring by means of a simple harmonic movement,
- Either by applying to the mass in vibration a force following a variable frequency.
- The SAN 413A is equipped with two graphic recorders. The first performs amplitude / frequency measurement continuously. The second, on a drum, performs the amplitude / phase measurement. A fractional power variable speed motor drives the excitation devices. It is provided with a speed control comprising a frequency indicator.
- Study of the relation between the mass of a body, the stiffness of the spring and the period or frequency of oscillation of a simple system spring / mass having a degree of freedom.
- Study of the influence of viscous damping on fiber vibrations of a simple spring / mass / damper system.
- Determination of the ratio or damping factor for a given spring / mass / damper system.
- Study of the relation between the amplitude of the vibration in steady state of the vibrating mass and the forced frequency for various damping factors.
- Vibrations caused by a periodic disturbing force applied to the mass.
- Vibrations caused by a periodic displacement of the point of attachment of the spring.
- Study of the phase ratio between the vibrating mass and the periodic movement of the point of attachment of the spring, for various damping factors
Supplied with user manual in French