ABSTRACT:

Understanding damage, localization and fracture in ductile solids and structures subjected to high velocity impacts or blast loadings has importance in aerospace industry, military applications, civil engineering and geophysical applications. Meteoric cratering, explosive behavior of projectiles or orbital debris impact on spacecraft structures are examples of situations in which to preserve the integrity of structures subjected to strain rates within the range >104 s -1 becomes crucial. From the early studies in this area –dating in the late 18th century– to the present time, an intense debate on the causes which reside behind the fragmentation of ductile solids has been carried out. This lecture provides an overview of the experimental and modelling efforts developed over the last >5 years by the Nonlinear Solid Mechanics group to identify the mechanisms controlling dynamic plastic localization and fragmentation in additive-manufactured porous metallic materials. While this is an ongoing program that still needs several years to be completed, the original methodological procedures developed, and the preliminary results, are ready to be subjected to scientific discussion, including: (i) microstructural and macromechanical characterization of the materials using SEM analysis and X-ray tomography, (ii) original impact fragmentation and spall fracture experiments, (iii) microstructurally informed finite element modelling incorporating the internal porosity and crystallographic texture of the materials. The flexibility of the methodology to address dynamic fracture of composite materials and other multiphase engineering materials will be highlighted. Moreover, the drawbacks and limitations of the methodology, the bottlenecks in the research implementation, and the difficulties to find consistent quantitative agreement between experiments and theory will be also discussed.

Brief CV:

José A. Rodríguez-Martínez is Associate Professor in the Department of Continuum Mechanics and Structural Analysis of the UC3M and head of the research group Nonlinear Solid Mechanics (https://www.nonsolmecgroup.com/). He graduated with honors in Industrial Engineering (2007), and obtained a Master’s degree in Advanced Structural Mechanics (2008) and a PhD in Mechanical Engineering (2010) from the UC3M. He also obtained a PhD in Mechanics of Materials from the University Paul Verlaine of Metz (2010). His doctoral Thesis received the maximum grade (Cum Laude) and the Doctor Europeus Label. He received the extraordinary doctorate award from the UC3M and the Association of Industrial Engineers of the Region of Madrid. He also obtained a reciprocal Chair of Excellence awarded by the UC3M, together with Professor Oana Cazacu (University of Florida), during the academic year 2018/2019, and the UC3M Social Council Excellence Award 2022. Dr. Rodríguez-Martínez has published >75 papers in international journals indexed in the JCR (including JMPS, IJP, IJSS, MOM, etc.), >50 of them in Q1 journals. His publications have obtained 1557 citations (source: Scopus), so that he has an h-index=23 (source: Scopus). Dr. Rodríguez-Martínez has submitted >80 contributions to scientific conferences, being the speaker >40 times. He has delivered invited lectures in >10 international conferences, e.g. IUTAM Symposium 2014 (Haifa), ICACM 2017 (Florida), EUROMECH Colloquium 2018 (Seville), ICPDF 2019 (Panama), ICEME-ASME 2019 (Salt Lake City), IUTAM Symposium 2022 (Warsaw), etc. Dr. Rodríguez-Martínez was awarded with an ERC Starting Grant in 2017 funded with 1.5 M€, with an US AFOSR Grant in 2021 funded with 180 k$ and with a Leonardo Grant funded by BBVA foundation in 2021 with 40 k$. In addition, he is coordinator of a project MSCA-RISE-2017 framed within the program H2020 and funded with 153 k€, and he was principal investigator of an international network MSCA-ITN-ETN-2015 also framed within the program H2020 and funded with 2 M€. He also participates in a project MSCA-SE-2022 funded with 184 k€. Dr. Rodríguez-Martínez was also the principal investigator of a national project -EUIN2015- funded with 25 k€, and he has participated in 11 additional projects funded in competitive regional and national calls. He also has been principal investigator in 2 contracts with private companies and has participated in 14 additional contracts. Dr. Rodríguez-Martínez has been visiting scientist in the Technion (Israel) for different periods of ½ -1 month per year since 2013 until 2018, in the University of Lorraine (France) for different periods of 1-2 months per year since 2013 until 2017, in the Texas A&M University (USA) for five periods of ½ -1 month from 2017 to 2022, and in the University of Florida (USA) for 3 months in 2019 and 1 month in 2022. Note that Dr. Rodríguez-Martínez has delivered invited seminars at different prestigious institutions like the Columbia University (USA), University of Texas at Austin (USA), Texas A&M University (USA), DTU (Denmark), CERN (Switzerland), etc. Moreover, he was invited in 2019 to a Window of Science organized by the Air Force Research Lab (USA) at the headquarters of Dayton (Ohio). Dr. Rodríguez-Martínez has supervised 5 PhD students who graduated in 2013, 2015, 2017, 2019 and 2020, and he is currently supervising 5 more that will graduate in 2023 (3 of them), 2024 and 2025. In addition, he has supervised 3 Postdoctoral Researchers, and he is currently mentoring a 1 MSCA CONEX Plus fellow. Dr. RodríguezMartínez has been the Chairman of 3 international conferences devoted to study the Dynamic Behaviour of Solids and Structures: the first of these conferences was held in 2013 (Workshop on Dynamic Behaviour of Materials and its Applications in Industrial Processes), the second one in 2016 (IUTAM Symposium on Dynamic Instabilities in Solids) and the third one in 2019 (EUROMECH Colloquium in Damage and Failure of Engineering Materials Under Loading Conditions). He is also chairman of the SEMTA-MECAMAT international colloquium “Mechanics across the Scales” to the held in Toledo in October 2023. In addition, he has organized >10 thematic sessions in international conferences including ICPDF 2018, EMI2016, SOLMECH2018, WCCM2018, SES 2018, ICPDF 2019, MACH2022, etc. Dr. Rodríguez-Martínez is Associate Editor of the Journal of Engineering Materials and Technology edited by the ASME and member of the Editorial Advisory Board of International Journal of Plasticity edited by ELSEVIER. He is reviewer for more than 30 international journals including Journal of the Mechanics and Physics of Solids, International Journal of Plasticity, International Journal of Solids and Structures, Mechanics of Materials, etc. Dr. Rodríguez-Martínez served as reviewer for the H2020 program from 2016 to 2019. He is secretary and founding member of the Spanish Society of Applied and Theoretical Mechanics (SEMTA) and member of several national and international scientific societies (GEF, ASME, EUROMECH, DYMAT). Dr. Rodríguez-Martínez has coordinated a course at the CISM in 2018 titled “Damage and failure of materials under extreme conditions” and is coordinating another one in 2023 titled “Plastic anisotropy and damage from single crystal to engineering scale”.