BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Joga Rao DTSTART:20261111T080000Z DTEND:20261111T090000Z DTSTAMP:20261114T001029Z UID:MathMAC/68 DESCRIPTION:Title: Modeling the Mechanics of Multi-Stimuli Multi-Shape Memory Polymers\n by Joga Rao as part of Modelling of materials - theory\, model reduction a nd efficient numerical methods (UNCE MathMAC)\n\n\nAbstract\nShape memory polymers have the ability to retain multiple temporary shapes\, which can be reverted back to the original shape\, or to another temporary shape\, t hrough the use of a suitable trigger. The most common stimuli used are tem perature changes\, exposure to light\, and other activation mechanisms. Th ese temporary shapes can be very complex and varied\, involving large defo rmations. Because shape memory polymers are finding use in a wide variety of important applications ranging from aerospace and biomedical devices to sensors and actuators\, there is significant interest in modeling their b ehavior.\nThis talk will provide an overview of different types of shape m emory polymers—in particular\, crystallizable shape memory polymers and light-activated polymers. In crystallizable shape memory polymers\, the te mporary shape is fixed by a crystalline phase\, while the return to the or iginal shape is driven by the melting of this phase. For light-activated s hape memory polymers\, exposure to UV light at a specific frequency initia tes the formation of cross-links that fix the temporary shape\; exposure t o UV light of a different frequency cleaves these cross-links\, restoring the original shape.\nSpecifically\, we will focus on how these building bl ocks can be used to synthesize multi-shape memory polymers that respond to multiple stimuli\, either sequentially or in tandem. As a result\, comple x shape changes and activation behaviors become possible\, expanding the p otential applications for these materials. Furthermore\, we will discuss t he underlying mechanisms and our approach to formulating constitutive equa tions that model the thermo-mechanical behavior of these polymers. The app lication of the developed models to different boundary-value problems of i nterest will be discussed. Finally\, the model is implemented as a user ma terial subroutine (UMAT) in the finite element software package ABAQUS. To demonstrate the applicability of the developed constitutive models\, we n umerically simulate three-dimensional geometries undergoing complex shape- fixation and recovery cycles.\n LOCATION:https://researchseminars.org/talk/MathMAC/68/ END:VEVENT END:VCALENDAR