Department of Wood Science and Technology has already good connections ith team of prof. dr. Marius-Catalin Barbu from Salzburg University of pplied Sciences, Forest products Technology and Timber Construction, ampus Kuchl. Based on this collaborations prof. Fajdiga visited the Campus uchl for several times for a few months. These visits and lectures that he erformed during the visit led to invite prof. Fajdiga to become visiting rofessor at Salzburg University of Applied Sciences.
B.05 Guest lecturer at an institute/university
COBISS.SI-ID: 2442121This dissertation presents a methodology for fast and simple fatigue damage estimation in the early stages of product's development process. Besides, it enables simultaneous consideration of temperature effect on fatigue damage estimation in frequency domain approach. The proposed method was developed with modification of the original Dirlik method. It is suitable for fatigue damage estimation of products which are subjected to stationary Gaussian loads with zero mean. Furthermore, the method can be used for stress-life approach. Fatigue damage estimation needs input data in the form of known temperature dependent power spectral density of stress loads and the temperature loading history. The spectral analysis of the known power spectral densities enables the estimation of the spectral moments and bandwidth parameters. In the next step follows the estimation of the probability density function of stress amplitude of loading cycles. The temperature effect on the product is considered with the weighting factors. Finally, the known temperature dependent S-N curves and the Palmgren-Miner linear damage hypothesis enable the fatigue damage estimation. The proposed method is theoretically and experimentally validated. Furthermore, it was corroborated with numerical simulations. Finally, the method successfully enables fatigue damage estimation.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 14310683Research named Possibilities of using alternative materials for producing air-spring pistons and bead plates has been made for Veyance Technologies Europe d.o.o.. In the first part of the project, different types of materials have been evaluated in terms of suitability of the material for a variety of technological processes, which are necessary for the production of air-spring pistons and bead plates, mechanical properties and cost of the material. In the next stage, several concepts of piston and bead plate from alternative material were developed and evaluated. Best concepts were further optimized. Afterward, prototypes were made and experimentally tested. The project was completed with completion of all objectives, as the weight of all developed products decreased by more than 30 %, which was the first goal. Moreover, the technology for manufacturing of products from polymer materials is substantially simpler and cheaper than manufacturing technology of comparable steel parts. An additional advantage is corrosion resistance of polymer material, which means that the electroplating treatment or an appropriate dye is no longer necessary. This saves both the time and costs of manufacture, as well as reduces hazardous emissions into the nature. Within the project, technically sophisticated products have been developed as well as new knowledge and experience in polymeric product development was gained. It is also important that through close cooperation with development engineers of Veyance Technologies all new knowledge was transferred directly to industry.
F.06 Development of a new product
COBISS.SI-ID: 13854747Numerical and experimental fatigue-life analyses of a connecting bar and a welded joint between the connecting bar and a connecting seat tube were performed. Two types of the connecting bar were considered, the one that is already produced and the new one with optimized design. Numerical simulations were performed with Abaqus implicit solver. The welded joint fatigue-life was estimated with own-written code based on a Smith-Watson-Topper parameter and with EUROCODE 3-1.9 standard. Furthermore a set of experimental dynamic tests were performed to determine welded joint fatigue-life. A study objective was to determine whether the welded joint fatigue-life in case of the new connecting bar is better than in case of the current one.
F.06 Development of a new product
COBISS.SI-ID: 13991451Dynamic simulations and analyses of toggling for current series of the electrical switches from TEM Čatež were performed. Numerical simulations were performed with Ls-Dyna explicit solver. Velocities, forces and accelerations during switch operation were recorded. Simulation results enable a redesign of the current electrical switches to ensure soft, low noise switching and to eliminate causes for a contact welding inside the switches.
F.06 Development of a new product
COBISS.SI-ID: 13907227