NEW TECHNIQUE FOR RESIDUAL STRESS MEASUREMENT NDT p.i. Ennio Curto. Ennio Curto Via E. di Velo, 84 36100 Vicenza (Italy) TECHNICAL PAPER 57th DEFENSE WORKING GROUP ON NONDESTRUCTIVE TESTING 17 through 19 November, 2009 enniocurto@fastwebnet.it This type of non-destructive method NDT provides the possibility to measure residual stress and the effect of the service load with an impact device and a vibration measurement sensor. Internal stresses are to be considered as the following: 1) Operational strains referring to loads that the material is subject and calculated 2) Residual stresses in the material caused by heat treatments or stresses caused by welding, forging, casting, etc. The new technique is able to measure the applied load and residual stress that are balanced on the surface of the material, and in a relatively large volume, at times even the same size as the entire structures. This stress is part of the metal’s elasticity field and has a three axis spatial orientation. The system works through the accelerometer mounted with a magnetic base to generate the acceleration value of the vibrations created by the device impacting on the metal surface. The acceleration value, in combination with other parameters, permits obtaining the exact value of the residual stress or load applied in the desired point. This value will appear on the display directly in N / mm %B2. For non-magnetic metals, wax or gel will be used to mount the accelerometer. This new system, for buildings, bridges steel inspection is very simple for to use , portable ,measure exact values of residual stress due to welding and the applied loads. After many years of research and tests, and between e discover about elastics behavior in field of metal steel now is very practice inspection point to point building and bridge constructions. This new system let bridges steel inspection in very simple mode, is portable instrument and let to measure exact values of residual stress due to welding and the applied loads. www.scribd.com/doc/6067883/New-Technique-for-Residual-Stress-Measurement-NDT