Plenary Lecture

Method for determining the residual stress-strain state of welded structures through the Wavelet Transform

Professor Vincenzo Niola
Department of Mechanics and Energetics
Faculty of Engineering
University of Naples Federico II
E-mail: vincenzo.niola@unina.it

Abstract: The method refers to the technical field relating to the use of technology and non-destructive methods for the determination of residual stress-strain state induced in the welded structures.
Currently, for the determination of residual stress-strain state induced in the welded products, different methodologies are used which are distinguished in two main categories: destructive and nondestructive methods.
It has been developed a non-destructive method for determining the stress-strain state of welded structures which allows to identify and then point-out the areas (cluster) of the welded skin showing frequency bands emissivity related to the different thermal conductivity of the material that, due to thermoplastic important variations during the welding step, modify the morphology of its grains, and, consequently, the surface emissivity.
The proposed methodology allows to evaluate in real time, by means of non-destructive technique, the residual stress-strain state in the welded structures, using the wavelet transform.

Brief Biography of the Speaker: Vincenzo Niola is professor of Applied Mechanics at Naples University Federico II since 31 march 1987. After he got an Univerisity Degree in Mechanical Engineering, he started in january 1978 didactics activity as helper at course of Applied Mechanics and Machines et as member of their committee of examination. Since september 1979 he carried on that collaboration as owner of a scholarship from C.N.R. (National Research Council). Since december 1981 to march 1987 he was a researcher carrying on the practice course for Applied Mechanics, taking a part at examination meeting and working as proposer in many degree thesis. Since 1981 to 1984 he carried on his didactics activity as university teacher for Bioengineering course of locomotive apparatus at Orthopaedy and Traumathology specialization school of 2th Department of Medicine and Surgery of Naples University. Since 31 march 1987 is professor of Applied Mechanics at Naples University Federico II, and since A.A. 86/87 to A.A. 92/93 he carried on the Applied Mechanics and Machines course for electronic engineers, and since A.A. 93/94 to today carry on the Applied Mechanics course for computer science engineers. Since A.A. 88/89 to 89/90 he carried on as supply teacher the Applied Mechanics course for building engineers at Salerno Engineering University. By A.A. 94/95 to A.A. 97/98 he carried on as supply professor Tribology course at Naples University Federico II. By A.A. 2001/2002 he holds the chair of Applied Mechanics for University Degree of “Orthopaedic Technician” at 2th Department of Medicine and Surgery of Naples University. Since A.A. 2005/2006 is professor of Tribology and of Complements of Mechanics. During this years Prof. Vincenzo Niola has been the chairman of his courses examination meetings, and was proposer of many degree thesis.. During his activity Prof. Vincenzo Niola was owner of financings from MURST and (in past and present) cooperate scientifically with research corporation and national industries (MERISINTER, MONTEFLUOS, INDESIT, ALENIA, C.I.R.A.). He's scientific member of Naples research unit for PRIN 2003. He's fellow of Italian Association of Theoretical and Applied Mechanics (AIMETA). He's member of IFToMM Linkages on cams committee. He belongs to the International Scientific Committee of the "World Scientific and Engineering Academy and Society (WSEAS). He is President of the WSEAS Italy Chapter on the “Analysis of the Mechanical Systems”. He was been Chairman and "invited author" in some session of Internatinal Conferences. He's author of more than 150 national and international papers. Is author of two chapters in the international books. In the past he focused his research activity on:
• Applied Mechanics
• Tribology
• Robot dynamics
• Funicular Railways
• Static and dynamic behaviour of rotors on lubricated journal bearings
• Industrial robot calibration
• Analysis of Mechanical systems by means Wavelet Transform.
The Prof. Niola is member of the “Editorial Board” of two International Journals. He is also Editor-in-Chief of a International Journal. During these years he has also been speaker of a lot of invited plenary lectures in the International Conferences.