Matteo Montanari from UniPR (IT) to UBG (RS), June-July 2022

Hi everyone!

My name is Matteo, I am a PhD student at the University of Parma and I've just come back from my two months exchange period at the Faculty of Mechanical Engineering of the University of Belgrade. I had the opportunity and the privilege to work within professor Sedmak's research group: in particular, I participated in the mechanical characterization of a large number of 3D printed photopolymerized specimens, kindly manufactured by the PhD student Mihai Marghitas at the Polytechnic University of Timisoara by using the so called DLP ("Digital Light Processing") technology.

Beside research projects, I was also able to go sightseeing around the wonderful city of Belgrade and its surroundings and to dive into Balkan's culture and lifestyle. Overall, the experience has been fruitful and laid the foundations for exciting scientific collaborations.

Finally, I take the opportunity to deeply thank my Serbian colleagues for their amazing hospitality.

Hvala!

Farzad Tatar from UniPR (IT) to UPT (RO), June-July 2022

I finished my two-month exchange period at the Politehnica University of Timisoara in August 2022. Indeed, everything there was a wonderful kind of its own. It was a pleasure for me to work directly with Professor Liviu Marsavina. He provided me with wonderful insights about my ongoing projects and also the experimental techniques in the lab.

During my stay there, I simulated and printed many metamaterials; the results will be published soon. In addition, I learned and read about different microscopy techniques and different instruments for measuring and studying a diverse array of materials' behavior. I also participated in the 9th International Conference on Advanced Materials and Structures. It was a pleasure for me that our paper, entitled "The effect of process parameters on fracture toughness of components obtained via DLP additive manufacturing technology" was presented.

Apart from the educational considerations, Prof. Marsavina was very kind and accommodating to me. He invited me to dinner several times, making the environment for me as close to my home as possible. Speaking of dinner and food, Timisoara has several delicious local cuisines that are highly recommended. In addition, people can easily communicate in English which is lovable for an international visitor. I look forward to getting back there and working with this wonderful group.

Qingbo Wang from NTNU (NOR) to UNIPR (IT), July & Nov.-Dec. 2022

I had a two-month exchange period at the University of Parma in 2022. It was a great opportunity for me to have a deep conversation with other researchers to work on the additive manufacturing study. Especially, Professor Roberto Brighenti and his PhD students helped me a lot with the theoretical study and experiments.

My main work was to focus on the topological design of fatigue resistance structures based on deep learning and additive manufacturing. I tried to develop a criterion to predict the fracture load of a novel designed non-constant notch which has higher fatigue resistance than standard U and V notches. I have printed some specimens and done the related mechanical tests with the help form the research group of Professor Roberto Brighenti. I also participated in the workshop and conference of project SIRAMM and received some helpful advice from the presentations.

Additionally, I also had a wonderful chance to get close to Italians and experience their food and culture. The fantastic historic buildings and enthusiastic Italians gave me an excellent and unforgettable journey.

Radek Kubicek from IPM (CZ) to NTNU (NOR), June-July 2022

Hello, my name is Radek and I am working as a PhD student at Institute of Physics of Materials Czech Academy of Sciences, Brno, Czech Republic (IPM). My PhD study is focus on the crack closure phenomenon, which significantly influences fatigue crack growth and is important for estimations of residual fatigue life of components. Thanks to the project SIRAMM and the IPM I've spent two months in Trondheim at the Department of Mechanical and Industrial Engineering, Norwegian University of Technology (NTNU). Since this close collaboration with NTNU and Associate Professor Seyed Mohammad Javad Razavi I was able to visit and use their very well-equipped laboratories of high cycle fatigue, low cycle fatigue, microscopes etc. There were many machines and technologies I had not been in touch with before. The two-month internship was very pleasant and beneficial for my field of focus and future research. Working with another PhD and exchange students was enriching and helpful. The internship was very well managed and besides the research activities, I spent a wonderful time with other students exploring Norwegian nature and culture.

I really appreciate this opportunity and many thanks to my Norwegian colleagues.  I look forward to our next cooperation.

Aleksa Milovanovic  from UBG (RS) to IPM (CZ), Feb.-March 2022

My visit to the Institute of Physics of Materials (IPM) Brno was a great opportunity to be involved in the dynamic testing of Additively Manufactured (AMed) metals and polymers. Thanks to our colleagues from the Institute I was involved in the next stage of testing of Ni-base superalloy Inconel 939, which started at the University of Belgrade (UB) with tensile tests. IN939 fatigue specimens were already AMed and sent to IPM, before my arrival. I had an opportunity to see, learn and participate in dynamic tests of AMed metallic specimens. Here, I saw all stages of specimen preparation, fatigue testing, and SEM microscopy imaging and analysis. Also, IN939 tensile specimens, tested in Belgrade, were measured for hardness on Vickers device. Some of the results from IN939 are already published, with the maximum effort of Dr. I. Sulak, Dr. A. Chlupova and M.Sc. T. Babinsky. And more results from these tests will follow. Regarding AMed polymers, I brought with me some PLA material CT specimens from UB, regular ones and side-grooved, for dynamic testing. CT specimens were AMed on FDM machine, with geometry suggested from Dr. Poduska and M.Sc. Travniček. With their help, effort, and knowledge, CT specimens were tested on fatigue machine with monitored crack propagation using cameras placed at each side of the CT specimen. Some of the results will be presented in the following ECF23 conference, held in Madeira, Portugal.

During this exchange period, I had a pleasant time with colleagues from the Institute during lunch breaks and after work over a beer (or two). I had an enjoyable experience exploring Brno and its surroundings. Famous Austerlitz battle took place around nowadays Brno, and all the historical cites were kindly and selflessly shown to me one weekend by Dr. Man, professor from the Institute who was an excellent guide. Also, one extended weekend was dedicated to the trip to Prague. Impressions from that trip direct me to come back again. This exchange period was specially enriched with exceptional cuisine and famous Czech beer.

Video on Aleksa's experience in Czech Republic

From UBG (RS) to Univ Parma (IT), Dec.-Jan. 2022

In the Winter period 2022/3, I visited the University of Parma and was involved in research that my colleague Matteo Montanari (UniPr) started during his stay at the University of Belgrade. Namely, some bending and flexural specimens made via MSLA additive manufacturing technology were tested at the University of Belgrade, and the data analysis was then performed at the University of Parma. Specimens were prepared by our PhD colleague from UPT, Mihai Marghitas. The results analysis was completed with the selfless help of professors Roberto Brighenti and Andrea Spagnoli, whose comments and suggestions guided us to the finalization of the research. Our work was presented at the Final conference of our project, held in Timisoara, Romania (SIRAMM23), the presentation title was: 'Compressive and flexural mechanical responses of components obtained through MSLA vat photopolymerization technology'. Results presented at the SIRAMM23 conference will be published soon.

During my stay in Parma, I had an opportunity to experience the city and its surroundings. Places in Parma I want to highlight are the city's cathedral, the palace Pilotta located in the city center with several museums and a lovely renaissance theatre incorporated in it, and a beautiful Teatro Regio (the city's Opera house) with more than a 1000-seat auditorium. One weekend was dedicated to the trip to see the Parma surroundings namely, the goal was to see the medieval castle Torrechiara. Except for the visual experience, Parma excels in food, coffee, and wine quality which I enjoyed during my stay. Weekends were also dedicated to visits to nearby cities, like Florence and Bologna.

Riccardo Alberini from UniPR (IT) to NTNU (N), Dec.2021, Jan-Feb. 2022

I am Riccardo, a PhD student at the University of Parma, and I started my exchange period in Trondheim at the Norwegian University of Technology. From this experience I expected to expand my knowledge and build important collaborations with professors and other PhD students for my research. Despite the pandemic situation, my expectations were confirmed and even exceeded. The environment at NTNU is welcoming and dynamic for foreign students, and there I had the occasion to collaborate even with professors from other universities. The department where I worked is well organized, providing foreign PhD students with offices, experiment facilities, software, and services. Due to the large number of exchanging students working in the department, I had many times the opportunity to talk with them and discuss about our job and impressions. This was very enriching and allowed me to establish new personal relationships for future scientific collaborations.

Ladislav Poczklan from IPM (CR) to UPT (RO), Oct.-Dec. 2021

My thesis deals with fatigue of metals. The stay at Polytechnic University of Timisoara was a great opportunity to get to know with different experimental material. I had a chance to see the process of manufacturing and testing of 3D printed plastic specimens. Another PhD student from Serbia brought a lot specimens with him so I could see how instrumented Charpy impact tests are performed and analyzed.

My main task was to help with setting of the Walter Bei fatigue machine so plastic specimens manufactured by additive technology could be tested on it. This machine was previously used for testing of metals. It means that setting of its PID regulators had to be substantially modified. We were able to do so after a consultation with official support. I found a proper set of PID for two materials which mechanical properties were pretty distinct (the ultimate stress 50 MPa and 125 MPa). The R ratio was 0.1 and specimens were cyclically loaded with a frequency 3 Hz. The problem was that for setting of the fatigue machine only specimens fabricated with traditional technology were used. When we finally tried to cycle 3D printed specimen a pressure in machine grips turned out to be too high. The pressure in machine grips caused a destruction of the specimen even though its value was the lowest possible. The only solution is probably in different design of the specimen but unfortunately there was not enough time to do so.

Beside research activities, I also had a chance to explore Timisoara which is a very nice city. I also visited nearby national park and other cities like Resita and Lugoj. The highlight of my stay was a trip to Belgrade. My colleague was there on his stay so I could see the city but also laboratories of University of Belgrade. 

Tomas Babinsky from IPM (CR) to UBG (RS), Oct.-Dec. 2021

In Autumn 2021 I spent two months at the University of Belgrade (UB) in Belgrade, Serbia thanks to the involvement of my parent institute, the Institute of Physics of Materials Brno (IPM Brno), in the SIRAMM project. In cooperation with colleagues from IPM and UB we started a project focused on microstructural characterization of fatigued 3D-printed (specifically DMLS - direct metal laser deposition) Ni-base superalloy IN939 which we first tested for tensile properties at UB. Some of the results obtained so far are going to be presented by Dr. Sulak in February 2022 at the SIRAMM conference held in Brno. Besides, I also took part in Mr. Milovanovic's project focused on the evaluation of fracture toughness and tensile properties of PLA and PLA-X plastics, to which I contributed with scanning electron microscopy analyses and the evaluation of experimental data. All in all, I believe the cooperation has been fruitful and might continue in the future.

Regarding personal, non-scientific experience, I enjoyed my stay in Serbia to the fullest. I met wonderful people, I enjoyed the exceptional Serbian food, I explored Belgrade as well as several parts of the country. I can definitely recommend hiking in Đerdap national park with its exceptional views or the mountains near Divčibare. In terms of city sightseeing, I can recommend visiting Novi Sad as well as Timisoara, Romania. However the biggest downfall of tourism in Serbia is the poor quality of public transport so I recommend borrowing a car if you don't come by one.

Mihai Marghitas from UPT (RO) to UniPR (IT), Oct.-Dec. 2021

 During my doctoral studies at UPT, I participated in an exchange of experience within the SIRAMM project, at University of Parma, Italy. The purpose of this exchange of experience was to enrich my knowledge, to study specialized publications and to carry out practical tests with 3D printers.

Testing 3D printed specimens is one of the main activities in my doctoral research. To obtain competitive products with this 3D printing mode, we test the specimens in the laboratory and note the results. The conclusions lead to a better understanding of the mechanical parameters of objects obtained by 3D printing, FDM or resins, and their comparison with products obtained by traditional methods. I participated in a technical exhibition at the University of Parma, which I liked, as a presentation and content. I saw interesting things and I appreciated the research work, the passion and the competitive spirit.

The exchange of experience at the faculty also had a cultural side, through the possibility of visiting the beautiful Italian cities of Trieste, La Spezia, Pisa, Modena, Bologna, Genoa, Florence, Milan, Mantua, Rome. I visited the Ferrari Museum in Maranello. I visited the Vatican Museum, where I was especially impressed by the Sistine Chapel. At Tivoli, the museum and gardens are fascinating.

I was glad to taste and see the places where Parma ham and Parmigiano Reggiano are produced, I admired fashion at the highest level, I saw the cities dressed for the holiday and the joy of the Italians to enjoy the moment.

Video on Mihai's experience in Italy

Aleksa Milovanovic and Isaak Trajkovic from UBG (RS) to UPT (RO), Oct.-Dec. 2021

We are grateful and honoured that we participated in the student exchange activity from mid-October to late December 2021 in Timisoara, Romania. The city of Timisoara is the capital of the Romanian Banat region and is the biggest city in the whole of Banat, which is a geographical and historical region of South-Eastern Europe, shared between Romania, Serbia and Hungary. Our hometown Belgrade borders this geographical region and the cultural traits of Banat are familiar to us. The cultural and ethnic diversity of this region makes it a very special and unique place in Europe. This two-month-long stay allowed us to be a part of this city from late Autumn up until the beginning of the Winter period, just before the Christmas holidays. We will never forget the long walks along the river Bega, spacious downtown squares filled with cafes and restaurants and beautiful churches, which are the most well-known landmarks of this city. During our stay, we have experienced the friendly nature of people from Timisoara when we asked for directions and during short conversations with local people in the hope of learning some words from the Romanian language.

Our working hours were spent at UPT, at the Department of Mechanics and Strength of Materials where we were studying and working with the available testing equipment. We take this opportunity to praise our colleagues from UPT for their hospitality, selfless help and guidance during our two-month-long exchange period. Besides getting acquainted with their equipment, professor Marsavina has arranged a few visits to neighbouring Institutes, where except for mechanical testing we have seen that our cooperation can be extended with material characterization techniques, using optical, SEM and TEM microscopes. Most of the exchange period was used to test PLA material Charpy specimens on instrumented pendulum and analysis of the obtained results. All Charpy specimens are 3D printed with a notch and have 80x10x4 mm in bulk dimensions. Before our stay we have prepared 30 specimen batches, with seven specimens per batch. Five specimens are mandatory according to the standard and the other two specimens serve as replacements. Variation in PLA specimens was in layer height i.e., 0.3, 0.2 and 0.1 mm, and in infill density, ranging from 10 up to 100%, with 10% increment. The reason for this is to see the layer height and infill density influence on impact toughness of PLA material. The effort in material testing and data analysis will be exploited in the publication of obtained results in Journal papers.

Video on Aleksa and Isaak's experiences in Romania