François Hild

François Hild, CNRS senior researcher at the Laboratory of Mechanics and Technology, ENS Paris-Saclay, has been recognized by CNRS for his work in materials mechanics.

Dr. Hild began his career with a focus on brittle fracture. This field is traditionally described by a part's defect statistics to identify its probability of failure. Starting from this rather narrow traditional base, where mechanical behaviour is overshadowed by the characterization of defects often caused by production processes, he completely renewed the approach to make the ingredients of the underlying statistical theory productive in a thermodynamically based and considerably broader mechanical framework.

The unified framework he developed serves to elucidate areas such as the damage of composite materials, fatigue of materials conditioned by micro-plasticity and dynamic fragmentation, and makes it possible to link the microscopic and macroscopic scales, in fields of application driven by the statistics of extremes rather than average behaviors.

A pioneer of image correlation

The second “period” of Dr. Hild's research, conducted in close collaboration with Stéphane Roux, concerns the current revolution in experimental mechanics through field measurements based on imaging, of which Dr. Hild is one of the pioneers.

By developing an original approach that uses numerical modelling tools to analyze mechanical tests, he became a trail-blazer in digital image correlation. Once again, he completely renewed the way “measurement” is considered in tests, and then the tests themselves, by making an increasingly close link with how the test is run, the description (CAD) of the parts being tested, their numerical modelling, or the identification of mechanical properties.

At the same time, the concept of “image” also developed massively into different modalities, different microscopies, the third dimension through tomography, and the fourth dimension through temporal series. Again, Dr. Hild has built a very broad, ambitious and, above all, extraordinarily fertile conceptual framework.

A significant academic and industrial impact

All of this research has been carried out in close collaboration with major industrial partners in the fields of energy, aeronautics and space, transport, and materials, reflecting the utmost relevance of the approaches Dr. Hild develops and their impact in a diverse range of application fields.

His research has been the subject of more than 230 articles, not to mention countless conference proceedings, book chapters and books, which enjoy a very high degree of recognition (as his h-index of nearly 50 shows). Patents and program protection also signal the extent of his intellectual property in these fields and consolidate, for example, the recent launch of the start-up Eikosim resulting from his team's scientific output.

François Hild and materials mechanics

Dr. Hild graduated from ENS Paris-Saclay (then ENS Cachan) with an agrégation in mechanical engineering. He earned a doctorate from Université Pierre et Marie Curie (Paris 6) and a PhD from the University of California at Santa Barbara. He has conducted most of his research at the Laboratory of Mechanics and Technology (LMT).

He has previously received the 1995 CNRS bronze medal (which honours a young researcher) and various prestigious awards including the 1998 Jean Mandel Prize and the 2014 Lazan Award from the Society for Experimental Mechanics. The silver medal he is honoured with today commends the significant international influence of his research as a whole.

The CNRS Silver Medal is a prestigious award that honours researchers (CNRS or not) who are recognized nationally and internationally for the originality, quality and importance of their research. It is awarded to around 20 researchers each year from any of the disciplinary fields covered by CNRS's 41 sections.