BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//7.3.3//EN TZID:America/New_York X-WR-TIMEZONE:America/New_York BEGIN:VEVENT UID:0-5065@eng.ufl.edu DTSTART;TZID=America/New_York:20220818T124500 DTEND;TZID=America/New_York:20220818T134500 DTSTAMP:20251201T210234Z URL:https://www.eng.ufl.edu/news-events/events/tp-seminar-modeling-the-mec hanical-response-of-polycrystalline-systems-based-on-new/ SUMMARY:T&\;P Seminar - Modeling the mechanical response of polycrystall ine systems based on new DESCRIPTION:Modeling the mechanical response of polycrystalline systems bas ed on new single crystal constitutive models\nTuesday\, August 18\, 2022\, at 12:50 pm\nLocation: MAE-A 303\nDr. Benoit Revil-Baudard\nAssistant Res earch Scientist\nDepartment of Mechanical &\; Aerospace Engineering\nUn iversity of Florida\nAbstract\nDuring a hypersonic operation\, there is po tential for extreme thermal loading during flight and severe impact loadin g during penetration which may lead to adverse transformations of the ener getics payload. Even though the overall (bulk) temperature of the energeti c system is too low to ignite\, local peaks in temperature could induce pa rtial burn\, which may result in non-ideal functioning of the payload\, e. g.\, much of the explosive remains either unreacted or partially burnt.\nI n this talk are presented very recent theoretical and computational capabi lities developed to respond to the need to realistically predict the large -scale thermo-mechanical response of energetic materials under dynamic loa dings. The key idea behind these efforts is that a realistic description o f the response of the payload can be achieved only if the crystallinity of the energetic systems and most importantly\, the specific anisotropy in t he plastic flow of the constituent crystals are accurately modeled. A new single-crystal model that accounts for intrinsic symmetries associated to the crystal lattice and a new computationally efficient framework for the description of the aggregate system response has been developed. Specifica lly\, with this newly developed framework\, the orientation\, plastic stra ins\, and stresses in the individual grains are continuously updated\, so the predicted macroscopic scale response accounts for the evolution of the thermo-mechanical state at the lower scale.\nThe application of this comp utational model is illustrated by simulating the response of a pentaerythr itol tetranitrate (PETN) polycrystalline high energetic system when subjec ted to high strain rate loadings. Strong differences in temperature and st resses between the constituent grains\, depending on their relative orient ation with respect to the wave direction are revealed. Furthermore\, the r ise in temperature in certain grains may be well in excess of the overall value. 3-D FE simulations of the impact of a penetrator made of high-stren gth steel containing a PETN energetic system are also presented providing insights into the complex interactions between the energetic system and th e metallic casing material. It is shown that if the crystallinity of the e nergetic system is neglected\, the predicted temperature rises and the ext ent of the zone of maximum heating in the energetic system during the impa ct event differ noticeably from those obtained with the new polycrystallin e model which accounts for the crystallinity of the PETN material and the anisotropy in the plastic flow of its constituent crystals.\nBiography\nDr . Benoit Revil-Baudard is a research scientist in the Department of Mechan ical and Aerospace Engineering at UF-REEF. He holds a MS/BS (Ingénieur Di plômé) from the Institut National des Sciences Appliquées de Lyon and a Ph.D. from Ecole des Mines de Paris. He has contributed to several areas including computational mechanics and advanced manufacturing of metallic m aterials and textile composites. At the UF-REEF\, he has developed a resea rch program and research laboratory devoted to the study of the response o f heterogeneous materials and multi-materials systems to extreme loadings. While the focus of his research activities is on the modeling of material s and structures\, he has developed and designed innovative experimental c apabilities and provided technology solutions to the defense sector. His r esearch has received continued support both from AFOSR and the US Air Forc e Research Laboratory Munitions Directorate. He has co-authored 2 books\, co-edited one book\, and authored or co-authored over 50 refereed papers. In the past 10 years\, he has delivered invited and keynote lectures at ma jor conferences in the field. He has been active in co-organizing topical symposia and promoting international research collaborations.\nMAE Faculty Host: Peter Ifju CATEGORIES:Seminars LOCATION:MAE-A Room 303\, 939 Sweetwater Drive\, Gainesville\, FL\, 32611\, United States GEO:29.643814;-82.34865 X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=939 Sweetwater Drive\, Gain esville\, FL\, 32611\, United States;X-APPLE-RADIUS=100;X-TITLE=MAE-A Room 303:geo:29.643814,-82.34865 END:VEVENT BEGIN:VTIMEZONE TZID:America/New_York X-LIC-LOCATION:America/New_York BEGIN:DAYLIGHT DTSTART:20220313T030000 TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT END:DAYLIGHT END:VTIMEZONE END:VCALENDAR