PSI - Issue 64

Valentina Tomei et al. / Procedia Structural Integrity 64 (2024) 901–907 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

902 2

1. Introduction 3D printing is rapidly spreading in various fields, among which that of cultural heritage preservation. Advancements in technology and materials have made 3D printing more accessible, leading to the introduction of this in different research fields, showing its high potentialities. In the field of cultural heritage applications, recent studies [Xu et al. (2017) and Higueras et al. (2021)], particularly explored the use of 3D printing to rebuild missing components of historical artifacts. In a larger scale, Fotia et al. (2021) even used 3D printing to recreate an entire village in scale based on scans from drones and laser scanners. Beyond specific applications, other research activities focus on the mechanical characterization of the materials composing 3D printed components, in terms of stiffness, strength and ductility, also considering the effect on these of the printing parameters, such as the direction of the printed layers [Monaldo et al. (2023),Tomei et al. 2024)]. This is a fundamental step in the exploration of 3D printed components for architectural/structural applications. The present study explores the feasibility of utilizing 3D printing for the restoration of historical structures and health monitoring purposes. To achieve this, tensile tests were conducted on samples derived from a 3D printing process here proposed, designed to facilitate the incorporation of fiber optic filaments within the samples. Moreover, considering the potential exposure of 3D printed components to environmental effects, some of the samples underwent Accelerated The aim of this study is to explore the tensile behavior of 3D-printed components realized through Additive Manufacturing (AM). The investigation focuses on several factors that could affect the tensile behavior of the samples: the printing path, the presence of optical fiber sensors (FOSs) introduced into the sample during the printing process, the effects of aging. For this purpose, dog-bone samples were manufactured using Additive Manufacturing (AM) technology, specifically employing the Fused Filament Technique (FFT) and PolyLactic Acid (PLA) material. The samples were printed utilizing two distinct printing paths, referred to hereafter as 'Vertical' and 'Horizontal'. Additionally, some of these samples were equipped with fiber optics inserted during the printing process. Among these, a subset featured Fiber Bragg Grating (FBG) sensors within the fiber optics. Lastly, to evaluate the effects of aging, certain samples underwent Accelerated Aging tests prior to the tensile testing phase. H_dog-bone V_dog-bone H_F_dog-bone Aging tests before the tensile tests (Amza et al. (2021)). 2. 3D-printing process and description of the samples

inner zone printing -45 )

second layer printing

printing plane

edge printing

inner zone printing (+45 )

first layer printing

edge printing

(a) (c) Figure 1. Printing processes: (a) H_dog-bone samples, H_Ag_dog-bone samples; (b) V_dog-bone samples; (c) H_Fh_dog-bone samples, H_Fd_dog-bone samples, H_Fh(s)_dog-bone samples. (b)