Residual stress theory measurement new NDT.

Preface:

The equipment consists of a vibrometer and a pulse generator at constant energy.

The elastic energy transmitted from the pulse generator at constant energy, on the surface of the metal, variable with the hardness of the metal itself. This elastic energy, however, remains unchanged at each corresponding hardness.

The pulse of force from origin to an elastic deformation volumetric equal to:

Ee = ∫ ½ Vol. K dx.

Vol = Volumetric deformation

K = Elastic module reaction volumetric.

dx = Displacement.

At the same time gives a transverse vibration forced with energy equal to:

Ev = ∫ ½ m a dx

m = inertial mass

a = acceleration of vibration.

therefore

Ee = ∫ ½ Vol. K dx = Ev = ∫ ½ m a dx = constant

The value of residual stress, (with the elastic energy invariable), depends on the change from the module K values and inversely from dx. (other values are fixed

( π, D, ρ).

The variation of K therefore corresponds to a proportional variation of:

a (acceleration of vibration).

p.i.Ennio Curto

with Sadt. cn collaboration.