The term Vibration Stress Relief (VSR) identifies a metal-physical method of dimensional stabilization of a metal component or structure by means of forced vibrations. In use since the 1960s in the USA, the stress relieving method by means of forced vibrations consists in making the piece vibrate to be stabilized, for a certain period of time, at certain resonant frequencies thanks to a vibrator engine with variable eccentric masses.
When to perform vibration process:
The vibration process is functional to the reduction of the residual stresses that occur in any product that undergoes mechanical processing, welding, chemical or metallurgical processes.
Reducing residual stress means:
wooden hammers to neutralize possible deformations of the components.
Open-air exposure using day/night/year temperature cycle.
Fun fact: The method is still used today, despite the high cost of storage: up to two years of immobilization.
The so-called "foundry" method: consisting in the induction of a violent vibration with natural resonance obtained by dropping the component from a crane into a sand box, to prevent the onset of deformations during subsequent machine processing.
Furnace annealing: stress reduction through heat treatment.
If correctly applied, this method stands out for its high reliability.
In case of treatments with procedural errors, such as too rapid cooling or lack of constant temperature control, opposite results can be obtained, generating additional stresses such as structural deformation or dislocations.
Fun fact: it is the procedure that, today, is the best known and most widespread, despite the high cost, both in economic and environmental terms.
Vibratory stress relieving VSR:
It consists in making the piece vibrate for a certain period of time at certain resonance frequencies detected by the analysis system of the central unit; vibration is activated by a motor-vibrator with adjustable variable eccentric masses.
Fun fact: new, but not really brand new; this method of intervention has been in use since the 1960s in US