{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/113319"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/113319","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Hierarchical design of morphing shape-memory polymer structures via topology optimization","abstract":"Shape memory polymers (SMPs) are a class of active polymeric materials that have the ability to regain their original undeformed configuration from a deformed state under the application of an external stimulus. In this study, we focused on the design optimization of SMPs that are actuated by the application of a thermal gradient. This study puts forward an optimization framework for systematic design of shape morphing structures capable of exhibiting large deformations with SMPs. A hierarchical two-stage design procedure is adopted. In the first stage, basic unit structures including a twisting structure and a bending structure are designed using a topology optimization framework. A finite-element analysis incorporating the additive decomposition of small strains, is implemented to analyze and predict temperature-dependent displacement response of SMPs. The finite element method consists of a viscoelastic material model combined with a temperature-dependent strain storage mechanism, giving SMPs their characteristic property. The thermo-mechanical characteristics of SMPs are exploited to actuate structural deflection to enable morphing toward a target shape. A time-dependent adjoint sensitivity formulation implemented through a recursive algorithm is used to calculate the gradients required for the topology optimization algorithm. Multimaterial topology optimization combined with the thermo-mechanical programming cycle is used to optimally distribute the active and passive SMP materials within the design domain. This allows us to tailor the response of the structures to design them with specific target displacements, by exploiting the difference in the glass-transition temperatures of the two SMP materials. Forward analysis and sensitivity calculations are combined in an PETSc-based optimization framework to enable efficient multi-functional, multimaterial structural design with controlled deformations. In stage II of the design process, the basic twisting and bending structures are fabricated and their kinematic characteristics are validated using a 4D printing technique. The main goal of this design stage is to use these basic twisting and bending structures to computationally design a self-tying knot. A forward kinematics framework is implemented using these bending and twisting angles as input and the optimal sequence of the basic twisting and bending structures along a morphable kinematic chain are generated by using a genetic algorithm with a predetermined ideal knot chosen as the target shape. The optimal sequence is then 3D printed and subjected to the thermo-mechanical programming cycle to compare the kinematic characteristics of the computationally designed structure with the mathematical knot. The results obtained show good agreement between the ideal knot and the computational design.","abstract_html":"Shape memory polymers (SMPs) are a class of active polymeric materials that have the ability to regain their original undeformed configuration from a deformed state under the application of an external stimulus. In this study, we focused on the design optimization of SMPs that are actuated by the application of a thermal gradient. This study puts forward an optimization framework for systematic design of shape morphing structures capable of exhibiting large deformations with SMPs. A hierarchical two-stage design procedure is adopted. In the first stage, basic unit structures including a twisting structure and a bending structure are designed using a topology optimization framework. A finite-element analysis incorporating the additive decomposition of small strains, is implemented to analyze and predict temperature-dependent displacement response of SMPs. The finite element method consists of a viscoelastic material model combined with a temperature-dependent strain storage mechanism, giving SMPs their characteristic property. The thermo-mechanical characteristics of SMPs are exploited to actuate structural deflection to enable morphing toward a target shape. A time-dependent adjoint sensitivity formulation implemented through a recursive algorithm is used to calculate the gradients required for the topology optimization algorithm. Multimaterial topology optimization combined with the thermo-mechanical programming cycle is used to optimally distribute the active and passive SMP materials within the design domain. This allows us to tailor the response of the structures to design them with specific target displacements, by exploiting the difference in the glass-transition temperatures of the two SMP materials. Forward analysis and sensitivity calculations are combined in an PETSc-based optimization framework to enable efficient multi-functional, multimaterial structural design with controlled deformations. In stage II of the design process, the basic twisting and bending structures are fabricated and their kinematic characteristics are validated using a 4D printing technique. The main goal of this design stage is to use these basic twisting and bending structures to computationally design a self-tying knot. A forward kinematics framework is implemented using these bending and twisting angles as input and the optimal sequence of the basic twisting and bending structures along a morphable kinematic chain are generated by using a genetic algorithm with a predetermined ideal knot chosen as the target shape. The optimal sequence is then 3D printed and subjected to the thermo-mechanical programming cycle to compare the kinematic characteristics of the computationally designed structure with the mathematical knot. The results obtained show good agreement between the ideal knot and the computational design.","abstract_has_math":false,"creators":["Bhattacharyya, Anurag"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["James, Kai A.","Tortorelli, Daniel A.","Lambros, John","Zhang, X. Shelly"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-01-12T22:56:09Z","date_published":"2022-01-12T22:56:09Z","updated_at":"2026-07-22T22:24:53Z","subjects":["Topology Optimization, Shape Memory Polymers, Adjoint Sensitivity, 4D Printing"],"languages":["en"],"rights":["Copyright 2021 Anurag Bhattacharyya"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/113319","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["James, Kai A.","Tortorelli, Daniel A.","Lambros, John","Zhang, X. Shelly"]},{"key":"dc:creator","label":"Author","values":["Bhattacharyya, Anurag"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2022-01-12T22:56:09Z","2024-01-12T22:56:20Z","2021-07-15","2021-08"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Topology Optimization, Shape Memory Polymers, Adjoint Sensitivity, 4D Printing"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2021 Anurag Bhattacharyya"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/113319"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Shape memory polymers (SMPs) are a class of active polymeric materials that have the ability to regain their original undeformed configuration from a deformed state under the application of an external stimulus. In this study, we focused on the design optimization of SMPs that are actuated by the application of a thermal gradient. This study puts forward an optimization framework for systematic design of shape morphing structures capable of exhibiting large deformations with SMPs. A hierarchical two-stage design procedure is adopted. In the first stage, basic unit structures including a twisting structure and a bending structure are designed using a topology optimization framework. A finite-element analysis incorporating the additive decomposition of small strains, is implemented to analyze and predict temperature-dependent displacement response of SMPs. The finite element method consists of a viscoelastic material model combined with a temperature-dependent strain storage mechanism, giving SMPs their characteristic property. The thermo-mechanical characteristics of SMPs are exploited to actuate structural deflection to enable morphing toward a target shape. A time-dependent adjoint sensitivity formulation implemented through a recursive algorithm is used to calculate the gradients required for the topology optimization algorithm. Multimaterial topology optimization combined with the thermo-mechanical programming cycle is used to optimally distribute the active and passive SMP materials within the design domain. This allows us to tailor the response of the structures to design them with specific target displacements, by exploiting the difference in the glass-transition temperatures of the two SMP materials. Forward analysis and sensitivity calculations are combined in an PETSc-based optimization framework to enable efficient multi-functional, multimaterial structural design with controlled deformations. In stage II of the design process, the basic twisting and bending structures are fabricated and their kinematic characteristics are validated using a 4D printing technique. The main goal of this design stage is to use these basic twisting and bending structures to computationally design a self-tying knot. A forward kinematics framework is implemented using these bending and twisting angles as input and the optimal sequence of the basic twisting and bending structures along a morphable kinematic chain are generated by using a genetic algorithm with a predetermined ideal knot chosen as the target shape. The optimal sequence is then 3D printed and subjected to the thermo-mechanical programming cycle to compare the kinematic characteristics of the computationally designed structure with the mathematical knot. The results obtained show good agreement between the ideal knot and the computational design.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-08-01","The student, Anurag Bhattacharyya, accepted the attached license on 2021-07-14 at 13:31.","The student, Anurag Bhattacharyya, submitted this Dissertation for approval on 2021-07-14 at 14:59.","This Dissertation was approved for publication on 2021-07-15 at 10:51.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16935 on 2022-01-12 at 13:04:57","Made available in DSpace on 2022-01-12T22:56:09Z (GMT). No. of bitstreams: 2 BHATTACHARYYA-DISSERTATION-2021.pdf: 22705833 bytes, checksum: 1bfa21c0a1a0c93501ee7c367dc1c72c (MD5) LICENSE.txt: 4217 bytes, checksum: 3c15fb72643340b73b7f692917686f1b (MD5) Previous issue date: 2021-07-15","Embargo set by: Seth Robbins for item 121248 Lift date: 2024-01-12T22:56:20Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Hierarchical design of morphing shape-memory polymer structures via topology optimization"]}]}],"canonical_facts":{"dc:contributor":["James, Kai A.","Tortorelli, Daniel A.","Lambros, John","Zhang, X. Shelly"],"dc:creator":["Bhattacharyya, Anurag"],"dc:date":["2022-01-12T22:56:09Z","2024-01-12T22:56:20Z","2021-07-15","2021-08"],"dc:description":["Shape memory polymers (SMPs) are a class of active polymeric materials that have the ability to regain their original undeformed configuration from a deformed state under the application of an external stimulus. In this study, we focused on the design optimization of SMPs that are actuated by the application of a thermal gradient. This study puts forward an optimization framework for systematic design of shape morphing structures capable of exhibiting large deformations with SMPs. A hierarchical two-stage design procedure is adopted. In the first stage, basic unit structures including a twisting structure and a bending structure are designed using a topology optimization framework. A finite-element analysis incorporating the additive decomposition of small strains, is implemented to analyze and predict temperature-dependent displacement response of SMPs. The finite element method consists of a viscoelastic material model combined with a temperature-dependent strain storage mechanism, giving SMPs their characteristic property. The thermo-mechanical characteristics of SMPs are exploited to actuate structural deflection to enable morphing toward a target shape. A time-dependent adjoint sensitivity formulation implemented through a recursive algorithm is used to calculate the gradients required for the topology optimization algorithm. Multimaterial topology optimization combined with the thermo-mechanical programming cycle is used to optimally distribute the active and passive SMP materials within the design domain. This allows us to tailor the response of the structures to design them with specific target displacements, by exploiting the difference in the glass-transition temperatures of the two SMP materials. Forward analysis and sensitivity calculations are combined in an PETSc-based optimization framework to enable efficient multi-functional, multimaterial structural design with controlled deformations. In stage II of the design process, the basic twisting and bending structures are fabricated and their kinematic characteristics are validated using a 4D printing technique. The main goal of this design stage is to use these basic twisting and bending structures to computationally design a self-tying knot. A forward kinematics framework is implemented using these bending and twisting angles as input and the optimal sequence of the basic twisting and bending structures along a morphable kinematic chain are generated by using a genetic algorithm with a predetermined ideal knot chosen as the target shape. The optimal sequence is then 3D printed and subjected to the thermo-mechanical programming cycle to compare the kinematic characteristics of the computationally designed structure with the mathematical knot. The results obtained show good agreement between the ideal knot and the computational design.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-08-01","The student, Anurag Bhattacharyya, accepted the attached license on 2021-07-14 at 13:31.","The student, Anurag Bhattacharyya, submitted this Dissertation for approval on 2021-07-14 at 14:59.","This Dissertation was approved for publication on 2021-07-15 at 10:51.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16935 on 2022-01-12 at 13:04:57","Made available in DSpace on 2022-01-12T22:56:09Z (GMT). No. of bitstreams: 2 BHATTACHARYYA-DISSERTATION-2021.pdf: 22705833 bytes, checksum: 1bfa21c0a1a0c93501ee7c367dc1c72c (MD5) LICENSE.txt: 4217 bytes, checksum: 3c15fb72643340b73b7f692917686f1b (MD5) Previous issue date: 2021-07-15","Embargo set by: Seth Robbins for item 121248 Lift date: 2024-01-12T22:56:20Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/113319"],"dc:language":["en"],"dc:rights":["Copyright 2021 Anurag Bhattacharyya"],"dc:subject":["Topology Optimization, Shape Memory Polymers, Adjoint Sensitivity, 4D Printing"],"dc:title":["Hierarchical design of morphing shape-memory polymer structures via topology optimization"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:53Z"}