This booklet contains abstracts presented at the First Annual PhD Workshop held at University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, on July 3, 2015. Annual PhD Workshop is the integral part of new PhD programme of Mechanical Engineering, Naval Architecture, Aeronautical Engineering and Metallurgical Engineering, launched on academic year 2014/15. The new program is jointly developed by two faculties of University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture and Faculty of Metallurgy, in order to enhance efficiency of PhD education, to improve scientific excellence of two faculties as well as to facilitate scientific and research cooperation between the academia and the industry. PhD workshop is aimed to provide forum for exchange of ideas among PhD students, to get all PhD students at one place and to monitor progress of their PhD theses. Workshop should help students to strengthen their presentation skills and unify quality and transparency of PhD theses produced at different modules of PhD programme. Abstract in this booklet are structured in a way to encourage students to write clearly and concisely purposes of their PhD theses in order to bring their research closer to the wide community and even to those who are not specialists in the field. This booklet could be a valuable and relevant reference for PhD students and their mentors as it represents kind of milestone in the progress of their PhDs. It will also be useful for all stakeholders of PhD education to evaluate quality and progress of PhD theses. Finally, it can be useful for the industry in Croatia as it contains in one place most of the research efforts at two faculties. Contributions collected in the booklet of abstracts are from different modules of new PhD study: Process and Energy Engineering (9 contributions), Theory of Structures (6), Mechatronics and Robotics (4), Naval Architecture and Ocean Engineering (3), Industrial Engineering and Management (3), Scientific Metrology in Mechanical Engineering (1) and Computational Mechanics (1). Diversity of these topics clearly indicates broad and rich research interests and activities at the Faculty of Mechanical Engineering and Naval Architecture and Faculty of Metallurgy. It should be mentioned that presently more than 100 students are enrolled in PhD education at two faculties, but only those among them inscribed in new PhD programme are invited to participate at this First Annual PhD Workshop.