HOLOGRAPHIC METHOD FOR THE STUDY OF THE ELASTIC AND INELASTIC DEFORMATIONS OF SOME SOLID BODIES

Under the action of external factors, the dimensions, as well as many internal properties, of bodies change; using holographic interferometr y, even very small changes of this kind can be studied. Holographic st ress analysis allows one to establish the internal distribution of the stress in the medium, produced by external forces. Transparent sample s, in which the stress produces a distribution of the refractive index , are usually used. However, the deformations induced by external forc es are able, in some cases, to reveal the internal modifications in no ntransparent bodies. Mechanical deformations of some nonhomogeneous so lid media (as concrete used in construction), are not accurately elast ic. We present a holographic nondestructive method for studying the de formations of bars made of concrete, which are connected with some int ernal properties of the solid bars, such as the modulus of elasticity. The results we obtained reveal some deviations from the elastic defor mation model. (C) 1996 Society of Photo-Optical Instrumentation Engine ers.