PSI - Issue 42

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 ScienceDirect

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 42 (2022) 1282–1290

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 Abstract Over the last decades, 3D printing has found applications in all areas of engineering, ranging from electronics to biomedical industries, due to its efficiency in the use of the material in terms of mass customization and waste reduction and its high resolution and precision during the prototyping stage. Nevertheless, while the traditional additive manufacturing industry is developing new applications or proposing some improvement of the static and inanimate 3D printed components, a novel technology, i.e., 4D printing, is arising. 4D printing adds a temporal dimension to 3D by providing vitality to the design of shape-memory materials using an external stimulus to trigger the object transformation into another designed structure. This contribution aims to improve the available information on the Polylactic Acid (PLA) shape memory polymer (SMP) behaviour under the effect of homogeneous thermal stimuli. Consequently, this study deals with a first analysis to understand the proper methodology to activate the shape memory effect (SME) and achieve a programmed deformation. The preliminary experimental results are compared with a simplified Finite Element Analysis (FEA) model to analyze and better understand the SME. This work lays the foundation for later research to understand which optimal specimens' geometric parameters may enlarge the activation range in PLA specimens, enhancing their shape capabilities of detecting temperature modification close to the glass transition temperature (Tg). © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 23 European Conference on Fracture - ECF23 Preliminary optimization of shape memory polymers geometric parameters to enhance the thermal loads' activation range . 2 , . 1 , . 1 , . 1 , . 2 , . 1∗ Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norway (1) Department of Industrial Engineering, University of Naples Federico II, Naples, Italy (2) Abstract Over the last decades, 3D printing has found applications in all areas of engineering, ranging from electronics to biomedical industries, due to its efficiency in the use of the material in terms of mass customization and waste reduction and its high resolution and precision during the prototyping stage. Nevertheless, while the traditional additive manufacturing industry is developing new applications or proposing some improvement of the static and inanimate 3D printed components, a novel technology, i.e., 4D printing, is arising. 4D printing adds a temporal dimension to 3D by providing vitality to the design of shape-memory materials using an external stimulus to trigger the object transformation into another designed structure. This contribution aims to improve the available information on the Polylactic Acid (PLA) shape memory polymer (SMP) behaviour under the effect of homogeneous thermal stimuli. Consequently, this study deals with a first analysis to understand the proper methodology to activate the shape memory effect (SME) and achieve a programmed deformation. The preliminary experimental results are compared with a simplified Finite Element Analysis (FEA) model to analyze and better understand the SME. This work lays the foundation for later research to understand which optimal specimens' geometric parameters may enlarge the activation range in PLA specimens, enhancing their shape capabilities of detecting temperature modification close to the glass transition temperature (Tg). 23 European Conference on Fracture - ECF23 Preliminary op imization of shape memory polymers geom tric parameters to enhance the thermal loads' activation range . 2 , . 1 , . 1 , . 1 , . 2 , . 1∗ Department of Mechanical and Industrial Engineering, NTNU, Trondheim, Norway (1) Department of Industrial Engineering, University of Naples Federico II, Naples, Italy (2) 2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 2452 3216 © 2020 Th Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 1. Introduction and state of the art Three-dimensional (3D) printing has become a popular fabricating method for parts and devices over the last decade. 3D printing was initially classified as a medium for rapid prototyping, where printers were used to quickly create 1. Introduction and state of the art Three-dimensional (3D) printing has become a popular fabricating method for parts and devices over the last decade. 3D printing was initially classified as a medium for rapid prototyping, where printers were used to quickly create Keywords: 4D-Printing; Thermal Loads; Geometric parameters; Composite material; Classical Laminate Theory Keywords: 4D-Printing; Thermal Loads; Geometric parameters; Composite material; Classical Laminate Theory

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.163