Advanced metals and structures design group

group leader

prof. Lovre Krstulović-Opara, PhD

associates

prof. emer. Željko Domazet, PhD
assoc. prof. Tonći Piršić, PhD
assist. prof. Petra Bagavac, PhD
Alen Grebo, MScEng
Ante Medvidović, MScEng

Research topics

  1. Development of advanced methods for evaluating deformations based on computer learning in correlating thermograms and digital image correlation (DIC)
  2. Development, dynamic testing, thermographic and DIC evaluation of new auxetic, TPMS, and hybrid cellular structures
  3. Evaluation of the absorption characteristics of polymer composites produced by rapid prototyping and polymer injection molding methods
  4. Non-destructive thermographic testing of metals and composites based on active infrared thermography
  5. Development of advanced methods for processing and filtering thermographic images in non-destructive testing
  6. Biomechanical testing on the femur bone

Description of laboratory and equipment

  • Servo-hydraulic dynamic load frame INSTRON – quasistatic, fatigue and dynamic testing of materials and structures
  • 24 m/s instrumented INSTRON 9450 drop tower
  • Cooled middle-wave infrared InSb infrared camera Flir SC 5000 – enables thermographic NDT and tracing of yielding process in materials
  • Xenon flash lamp 6 kJ – generates heat flow in metals used for thermographic NDT of materials and structures
  • HBM MGC plus – multi-channel amplifier for strain gauges and thermo-couples
  • NDT equipment – ultrasound testing, penetrant testing, magnetic particles inspection visual testing
  • Nextengine 3D scanner
  • Krautkramer DM 4 – thickness measuring gauge
  • Krautkramer USM Go – A scan ultrasound device
  • UCI AlphaDur mini – Vickers hardness testing equipment

Contacts with academic and other institutions

  • University of Maribor, Faculty of Mechanical Engineering (FS), Slovenia
  • University of Ljubljana, Faculty of Mechanical Engineering (FS), Slovenia
  • University of Aveiro, Centre for Mechanical Technology and Automation (TEMA), Portugal
  • Tomáš Baťa University in Zlin, Faculty of Applied Informatics, Czechia
  • Centre for Mass and Thermal Transport in Engineering Materials, Discipline of Mechanical Engineering, University of Newcastle, Australia
  • Institute of Pulsed Power Science, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, Japan
  • National Institute of Technology, Kumamoto College, Kumamoto, Japan
  • University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture (FSB), Department of Applied Mechanics, Croatia
  • Campus 02 University of Applied Sciences, Graz, Austria
project title

Advanced material and structural evaluation and development (ADVMATSTRUCT)

Description of research in a 5-year term

Research in the field of artificial intelligence in the development and modification of DIC (digital image correlation) and infrared thermography in the evaluation of material plastification under dynamic loads. Testing various approaches to AI algorithms in linking thermography and DIC.

Continued development and testing of auxetic, hybrid, and TPMS structures with the University of Maribor. Tests include the characterization of mathematically generated periodic structures (TPMS) concerning the production method (sintering, casting). Further development of 2D and 3D auxetic structures, application of milling and laser cutting methods on 2D structures.

With the Faculty of Mechanical Engineering, Ljubljana, research on the development of finite elements for parameterization based on the Prandtl operator for temperature-dependent materials in the elasto-plastic region. This model avoids iterative determination of material parameters.

With Hospital of Dubrovnik, continued testing of femur bone fractures and fracture repairs under quasi-static, dynamic, and impact loads. Tests include changing bone strength parameters at various impact speeds and the effect of fracture fixation methods using implants. Previous tests revealed a strong dependence of the bone fracture mode on impact speed. Tests on implants did not include repaired bones after fracture, but rather the impact of implants on healthy bone, so further research will be conducted on previously fractured bones.

With Tomaš Bata University in Zlin, there is ongoing research of the absorption characteristics of polymer composites based on injection molding. Previous tests were conducted on anti-ballistic vests, and further research is planned on similar protective equipment (shields, helmets, etc.).