SIEMENS company has invited us to join a project the aim of which is to develop procedures for the prediction of the durability of lithium-ion batteries. It turns out that the damage mechanism that leads to the failure of the battery is fatigue. We have developed an algorithm that enables the modelling of the capacity of the battery as a function of voltage, current and temperature. We have presumed that voltage, current and temperature are random variables. Further on we have developed an algorithm that enables the conversion of voltage and the capacity of the battery into a damage parameter. Based on the calculated history of the damage parameter, the new procedure, based on Prandtl operators, can be used to predict the durability of the battery. We have tested the method preliminarily. In 2017, the method has been successfully validated on tests taken by Vrije Univeriseit, Brussels. Based on the topic of the project, two original scientific papers are being competed. As our work on the project has been estimated as very successful, we have been invited to join a new project H2020 called also IMMENSE, standing for Integrated and Interoperable Multiscale Modelling Solution for Electrochemical Energy Storage System. The project was submitted in January 2018.
F.06 Development of a new product
COBISS.SI-ID: 15797275Experimental analyses of high strength steel durability were at first performed for the company TPV d.d. within this project. In dynamic strength analyses of a vehicle’s trailing arm we used durability curves, which were obtained in these experimental analyses. Using ABAQUS and FEMFAT software we performed numerical simulations of trailing arm fatigue for elementary load cases, for cases with random load sequences and for cases with elastic-plastic loading. Simulations results show that TPV’s newly developed trailing arm is appropriate for the next phase of development. At the same time studies of numerical optimization of a dashboard carrier with attachments were performed. In these cases we combined ABAQUS and I-Sight software module to obtain stiffness requirements of the dashboard carrier while the carrier’s mass remains the same. In parallel with simulations and optimizations we also performed education of younger engineers from TPV d.d. company to work with FEMFAT software with focus on modelling and fatigue analysis of welded joints. That kind of analyses the company had not been performing before, therefore with our help they introduced FEMFAT software for the first time in their working environment.
F.04 Increase of the technological level
COBISS.SI-ID: 15759387Magnesium alloy for forming AZ31 behaves asymmetrically at cyclic loading. In the case of large strains, deformation mechanisms of twinning at the compressive branch and untwinning at the next tensile branch are exchanged, the two mechanisms are transformed into slip mechanism at large strains. With the material model for magnesium alloy AZ31, it is possible to simulate the stress-strain response at cyclic loading. Customer TPV.
F.04 Increase of the technological level
COBISS.SI-ID: 15609627At the test, we wanted to measure forces that are transmitted from the road to the front and rear wheels under realistic driving conditions. We designed special-purpose sensors with strain gauges and developed a measurement interface for the detection of loads. We determined the influence of speed, barrier size, impact of the bend, and the influence of acceleration and braking on wheel loads. Customer Gem Motors.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 15531291Current tubular hoisting and handling equipment for oil and gas industry that is used for lowering the pipe string into the drilled hole is not ideal since it makes substantial marks on the pipe wall. Because the pipe is subjected to a very hostile environment this causes the appearance of pitting or crevice corrosion on the pipe surface that further damages the pipe. Therefore, producers of the hoisting and handling equipment for oil and gas industry seeks for the technology that would allow hoisting and handling the pipes without leaving any marks on the pipe surface. This report presents: research of the mentioned problem (influence of marks on corrosion appearance), the process of finding a solution and newly developed technology. As a part of the research, the problem was divided into the basic physical principles for which individual solutions were sought. The biggest problem was to provide a sufficiently high friction force between the holder and the pipe. A series of potentially useful materials were tested in order to provide a sufficient coefficient of friction even in the most adverse environmental conditions (surface contaminated with oil or grease). Four completely new composite materials, with better characteristics compared to existing materials, have also been developed. Five different technologies have been proposed and evaluated to ensure sufficient radial force that presses frictional material towards the pipe. For the selected technology, a scaled down model of the tool was built and measurements performed. Measurements results indicated a successful solution. The newly developed technology with the possibility of changing the radial force enables the use of various friction materials in contact with the pipe. The tests showed that suitable materials do not leave any marks on the pipe, but these materials have a slightly lower coefficient of friction than materials leaving marks on the micro level. For the latter the experimental research on the impact of the micro trace on pitting corrosion is in progress. A completely new advanced technology, result of the presented research, enables a significant reduction of the oil pumping costs as it allows the use of pipes with a thinner wall and unlike the current state, repeated use of production pipes. In economic terms, this means millions savings in a single well. An application for international patent protection is also being prepared for the developed technology together with the concept of holding the pipe during lowering into the borehole.
F.06 Development of a new product
COBISS.SI-ID: 15728667