Holography is basically a two-step process for creating a whole three dimensional image of a diffusely reflecting object having some arbitrary shape. This article discusses the advantages, disadvantages and applications of using the optical holography method in nondestructive evaluation. It also discusses the types of acoustical holography, including liquid-surface acoustical holography and scanning acoustical holography. The article concludes by comparing liquid-surface and scanning systems.
This article reviews the various types of mechanical testing methods, including hardness testing; tension testing; compression testing; dynamic fracture testing; fracture toughness testing; fatigue life testing; fatigue crack growth testing; and creep, stress-rupture, and stress-relaxation testing. Shear testing, torsion testing, and formability testing are also discussed. The discussion of tension testing includes information about stress-strain curves and the properties described by them.