Pogled na SPA & GOLF RESORT Sv. MARTIN
Primjena IC termografije - radovi članova
Thermographic Analysis of Stress Distribution in Welded Joints
Autor: T. Pirsic, L. Krstulovic-Opara, Z. Domazet
Sažetak:
Rad naših članova objavljen na ICEM 14 kongresu u Poitiersu (Francuska) !
ABSTRACT.
The fatigue life prediction of welded joints based on S-N curves in conjunction with nominal stresses generally is not reliable. Stress distribution in welded area affected by geometrical inhomogeneity, irregular welded surface and weld toe radius is quite complex, so the local (structural) stress concept is accepted in recent papers. The aim of this paper is to determine the stress distribution in plate type aluminum welded joints, to analyze the reliability of TSA (Thermal Stress Analysis) in this kind of investigations, and to obtain numerical values for stress concentration factors for practical use. Stress distribution in aluminum butt and fillet welded joints is determined by using the three different methods: strain gauges measurement, thermal stress analysis and FEM. Obtained results show good agreement - the TSA mutually confirmed the FEM model and stresses measured by strain gauges. According to obtained results, it may be stated that TSA, as a relatively new measurement technique may in the future become a standard tool for the experimental investigation of stress concentration and fatigue in welded joints that can help to develop more accurate numerical tools for fatigue life prediction.
» snimi članak [pdf 347 Kb]
Thermal imaging and thermal stress analysis of the impact damage of composite materials
Autor: L. Krstulovic-Opara, B. Klarin, P. Neves, Z. Domazet
Sažetak:
Rad naših članova objavljen na kongresu: Proceedings of Fourth International Conference on Engineering Failure Analysis, ICEFA IV, 4. - 7. July, Cambridge, United Kingdom, 2010.
» snimi članak [pdf 199 Kb]PROCES ENERGETSKE CERTIFIKACIJE ZGRADA U HRVATSKOJ - PRIMJENA INFRACRVENE TERMOGRAFIJE
Autor: Dunja Mikulić, Bojan Milovanović, Vladimir Šimetin, Nada Marđetko Škoro
Sažetak:
Opisan je proces zadovoljavanja zahtjeva direktive 2002/91/EC i mogućnost upotrebe infracrvene termografije u provođenju energetskog certificiranja zgrada u Hrvatskoj. IC termografija se redovito koristi u otkrivanju defekata na vanjskoj ovojnici zgrade, kao što su toplinski mostovi, mjesta zrakopropusnosti ili velike vlažnosti. Također postoji i mogućnost procjene gubitaka topline što bi moglo imati značajnu ulogu u predstojećem procesu energetske certifikacije zgrada u Hrvatskoj, slijedeći direktivu 2002/91/EC.
» snimi članak [pdf 561 Kb]
Thermal Stress Analysis (Toplinska analiza naprezanja)
Autor: Lovre Krstulović - Opara, Branko Klarin, Želko Domazet
Sažetak:
Primjena termografije pri analizi naprezanja. U eksperimentalnom radu prikazana je procjena distribucije stresa na temelju toplinskih naprezanja. Analiza je obavljena na vjetroturbini. Rasipanje energije, zbog elastičnih naprezanja u strukturi, može se otkriti s infracrvenom kamerom.
Rad je objavljen na CMND 2009 kongresu u Splitu ( International Symposium on Coupled Methods in Numerical Dynamics, CMND 2009, eds.: Z. Terze, C. Lachor, 16-19 September 2009, Split, Croatia, 255-265, 2009.)
In presented paper experimental evaluation of the stress distribution based on the Thermal Stress Analysis has been performed on a wind turbine blade at the second modal vibration regime. Small wind turbine blade was exposed to a simple oscillating movement, similar to the real movement when the blade is mounted on a wind turbine rotor. Internal loads of the blade structure, caused by deflections during oscillated movement, provide energy dissipation in their internal material structure. Energy dissipation, due to the elastic stresses in the structure, can be detected with an infrared thermal imaging camera. The Finite Element modal frequency analysis of the 3D scanned model has been used to evaluate the global structural behaviour and approve Thermal Stress Analysis results. Structure of the blade was detected with ultrasonic probe. As a result, simple procedure for non-destructive structure analysis of the wind turbine blades is proposed.
» snimi članak [pdf 938 Kb]