Projects / Programmes
January 1, 2015
- December 31, 2018
| Code |
Science |
Field |
Subfield |
| 2.11.00 |
Engineering sciences and technologies |
Mechanical design |
|
| Code |
Science |
Field |
| T210 |
Technological sciences |
Mechanical engineering, hydraulics, vacuum technology, vibration and acoustic engineering |
| Code |
Science |
Field |
| 2.03 |
Engineering and Technology |
Mechanical engineering |
mixture distributions, power spectral densities, rubber composites, rheological models, energy methods, lithium-ion batteries, durability curves, fatigue strength, casted parts, hybrid structures, mechanical safety elements, wood, wood-based composites and hybrids, fracture mechanics, fatigue.
Researchers (15)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
20823 |
Tomaž Bešter |
Mechanical design |
Technical associate |
2015 - 2016 |
87 |
| 2. |
50469 |
Silva Brenčič |
|
Technical associate |
2017 - 2018 |
0 |
| 3. |
15683 |
PhD Gorazd Fajdiga |
Mechanical design |
Researcher |
2015 - 2018 |
268 |
| 4. |
34407 |
PhD Mitja Franko |
Mechanical design |
Researcher |
2015 - 2017 |
29 |
| 5. |
32075 |
PhD Aleš Gosar |
Mechanical design |
Researcher |
2015 - 2018 |
117 |
| 6. |
23494 |
PhD Bojan Gospodarič |
Forestry, wood and paper technology |
Researcher |
2015 - 2018 |
71 |
| 7. |
16334 |
PhD Jernej Klemenc |
Mechanical design |
Researcher |
2015 - 2018 |
806 |
| 8. |
22063 |
PhD Miran Merhar |
Forestry, wood and paper technology |
Researcher |
2015 - 2018 |
99 |
| 9. |
13469 |
PhD Marko Nagode |
Mechanical design |
Head |
2015 - 2018 |
834 |
| 10. |
18623 |
Miran Nerat |
|
Technical associate |
2015 - 2016 |
0 |
| 11. |
10370 |
PhD Ivan Okorn |
Mechanical design |
Researcher |
2015 - 2018 |
107 |
| 12. |
26561 |
PhD Simon Oman |
Mechanical design |
Researcher |
2015 - 2018 |
269 |
| 13. |
39189 |
PhD Branislav Panić |
Mechanical design |
Junior researcher |
2016 - 2018 |
25 |
| 14. |
29047 |
PhD Domen Šeruga |
Mechanical design |
Researcher |
2015 - 2018 |
341 |
| 15. |
28018 |
Drago Vidic |
|
Technical associate |
2015 - 2018 |
0 |
Organisations (2)
Abstract
As we want to split the available hours of the programme between several researches and thus enable them to research, we have decided to discuss the topics in a marked list. The marks are used throughout the complete text.
A. For mixture parameter estimation the rebmix algorithm has been developed. Further improvements are planned. The main aims are statistical proofs of the critical algorithm steps and the addition of new parametric families.
B. For fatigue life prediction in the frequency-domain, the original Dirlik method has been used. The main goal is the modification of the Dirlik method that will take into account the influence of varying temperature and specific load shapes.
C. In the field of rubber composites research will be focused on modelling the stress-strain states of rubber and rubber composites and the improvement of the method for predicting the fatigue life of rubber composites.
D. We want to improve the energy based method for the durability prediction of thermomechanically loaded components. The goals are an implementation of the mean stress effect and viscoplasticity regarding dissipated energy and the damage.
E. We have already developed methods for the lifetime prediction of metallic components exposed to thermomechanical fatigue (TMF). We want to investigate the possibilities of this approach to be appropriate to study the TMF of lithium-ion batteries.
F. Statistical models for modelling durability curves with a significant break-point will be improved. Our plan is to develop a statistical model that will not be based on the assumption of a homogenous scatter parameter along the durability curve.
G. A research related to the modelling of the fatigue life of casted parts with inhomogenities will be continued. The plan is to develop a phenomenologically correct model for predicting the fatigue life of casted parts with clusters of macro-pores. The inputs to the model will be the known material characteristics of a homogenous material and statistical variability of the geometry.
H. Research in the field of fatigue life of parts with a hybrid metal-nonmetal load-carrying structure will be continued. Our plan is to improve the numerical modelling and evaluation of hybrid structures with the goal of extending their fatigue life.
I. The methodology for predicting the behaviour of structures that are loaded with mechanical loads causing high strain rates in the material will be improved.
J. For wood products, the influence of the probability distribution of occurrence and location of inhomogeneities (annual ring, knot and other growth characteristics) on the material properties of wood will be determined.
K. The damage initiation and damage propagation periods during fatigue of wood and wood-based composites and hybrids will be investigated.
Significance for science
A. Mixture distributions stand for an important research field. The rebmix algorithm is original as it predicts unknown parameters sequentially and not simultaneously, like other algorithms. It enables an extension to classification and neural networks.
B. The modified Dirlik method enables a computationally fast fatigue life prediction with the effect of varying temperature. Taking high amplitude cycles into consideration will improve the safety of the method in case of their existence.
C. Rubber composites have not been fully researched yet. Therefore many open issues and research opportunities exist. Each new study contributes to a better understanding of their behaviour under different conditions of use.
D. Calculating dissipated energy by the Prandtl operators is advantageous over other methods as energy can be obtained at any time regardless of the shape of the hysteresis loop. An upgrade of the model will allow even better predictions.
E. Thermomechanical fatigue of lithium-ion batteries is a poorly researched area where it is hard to find any scientific publications. This research will contribute to the knowledge of the lifetime prediction of Li-ion batteries.
F. To model the durability curve in an ultra-high-cycle domain, its trend and scatter must be known below the Haibach's break point. The existing methods neglect this break point, but with our method it will be possible to adequately model the durability curve also in this domain.
G. The new method will enable an estimation of the fatigue-life reduction of dynamically-loaded structures that comprise clusters of macro-pores. This will improve the prediction of the fatigue life for casted parts as well as porous (foam) materials applied for light-weight design.
H. With a reliable simulation of stress-strain states of hybrid metal-nonmetal structures, their optimisation in the early stages of product design will be enabled. At the same time the prediction of their behaviour during real applications will be improved. Consequently, the range of experimental evaluation and its cost will be reduced.
I. The methodology will enable a better material characterisation and the simulation of product behaviour when exposed to shock loads in order to improve the product’s strength-to-weight ratio.
J. Due to its specific properties wood has not been fully researched yet. Therefore it provides many open issues and research opportunities. Each new study contributes to a better understanding of the properties and behavior of individual wood species and wood-based composites and hybrids under various conditions of use.
K. See point J.
Significance for the country
A. The rebmix package contributes to the promotion of the country and international division of work. Let us mention SomatiCA http://www.bioconductor.org/packages/release/bioc/html/SomatiCA.html that uses rebmix in medicine.
B. See point D.
C. Our research group has been actively involved in working with the company Veyance Technologies over a long period of time. Therefore all the acquired knowledge and development in the field of rubber products is directly transferred to the company, which contributes to its success and competitiveness.
D. We create opportunities for the implementation of the developed methodology in the early phases of the development & design process for automotive industry, machine manufacturing and energy industry. This influences the consumption of raw materials and reduces production cost per unit. During joint projects with business partners the developed knowledge will be transferred to industry.
E. Electrically propelled vehicles have a major impact on traffic, mobility and environment allowing zero-emission vehicles and decreasing the dependence on imported oil as a single energy source.
F. The Haibach's break point of modern spring steels is often below one million load cycles. However, modern spring steels are applied to products loaded with hundreds of millions of load cycles (e.g. road and rail transport). Our method will enable a better characterization of these steels that are also produced by Slovenian steelworks.
G. In automotive industry the main trend is linked the reduction of a vehicle's mass in order to reduce greenhouse-gas emissions. Hence more and more light-weight casted parts and porous elements are built into vehicles. Our method will simplify and shorten the R&D process of such elements, which are produced in Slovenia, too.
H. Vehicle mass is often reduced also with an application of hybrid metal-nonmetal structural parts. Reliable simulations are the basis for numerical R&D evaluations of hybrid structural parts and can bring a sustainable competitive advantage to Slovenian companies that produce such components (e.g. producers of headlamps or safety elements).
I. The development of vehicle safety elements with less experimental effort is possible only if material behavior is well known and characterized. With our methodology the current R&D process of such components can be improved.
J. Wood as a "clean" material will remain an important raw material. Slovenia is rich in wood. Knowing the fracture-mechanical properties of individual wood species and wood-based materials (hybrid, composites) is extremely important and can be a competitive advantage to Slovenian companies.
K. See point J.
Most important scientific results
Annual report
2015,
2016,
2017,
final report
Most important socioeconomically and culturally relevant results
Annual report
2015,
2016,
2017,
final report
