ESTCB - Escola Superior de Tecnologia
URI permanente desta comunidade:
Navegar
Percorrer ESTCB - Escola Superior de Tecnologia por Objetivos de Desenvolvimento Sustentável (ODS) "09:Indústria, Inovação e Infraestruturas"
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- Determination of dynamic elastic properties of 3D-printed nylon 12CF using impulse excitation of vibrationPublication . Garcia, Pedro F.; Ramalho, Armando; Vasco, Joel; Rubén, Rui; Capela, Carlos; MDPIMaterial Extrusion (MEX) process is increasingly used to fabricate components for structural applications, driven by the availability of advanced materials and greater industrial adoption. In these contexts, understanding the mechanical performance of printed parts is crucial. However, conventional methods for assessing anisotropic elastic behavior often rely on expensive equipment and time-consuming procedures. The aim of this study is to evaluate the applicability of the impulse excitation of vibration (IEV) in characterizing the dynamic mechanical properties of a 3D-printed composite material. Tensile tests were also performed to compare quasi-static properties with the dynamic ones obtained through IEV. The tested material, Nylon 12CF, contains 35% short carbon fibers by weight and is commercially available from Stratasys. It is used in the fused deposition modeling (FDM) process, a Material Extrusion technology, and exhibits anisotropic mechanical properties. This is further reinforced by the filament deposition process, which affects the mechanical response of printed parts. Young’s modulus obtained in the direction perpendicular to the deposition plane (E33), obtained via IEV, was 14.77% higher than the value in the technical datasheet. Comparing methods, the Young’s modulus obtained in the deposition plane, in an inclined direction of 45 degrees in relation to the deposition direction (E45), showed a 22.95% difference between IEV and tensile tests, while Poisson’s ratio in the deposition plane (v12) differed by 6.78%. This data is critical for designing parts subject to demanding service conditions, and the results obtained (orthotropic elastic properties) can be used in finite element simulation software. Ultimately, this work reinforces the potential of the IEV method as an accessible and consistent alternative for characterizing the anisotropic properties of components produced through additive manufacturing (AM).
- Dynamic elastic properties of E-Glass randomly oriented fiber reinforced SR GreenPoxy composite - Experimental and numerical analysisPublication . Ramalho, Armando; Gaspar, Marcelo; Correia, Mário; Vasco, Joel; Capela, Carlos; Rubén, RuiIn this article, the in-plane dynamic elastic properties of an E-glass randomly oriented fiber-reinforced SR GreenPoxy 56 composite were obtained based on the procedure specified in the ASTM E1876-21 standard. The experimental frequencies and the ones predicted by the simulation of the experimental procedure using a finite element analysis developed in the Patran/Nastran 2021 package were used in an iterative algorithm using sensitivity analysis to improve the first approaches of the dynamic elastic properties obtained by the impulse excitation technique. These experimental results are compared with the ones obtained by the 2D Short Fiber Composite model of the E-glass randomly oriented fiber-reinforced SR GreenPoxy 56 composite, developed in the Patran/Nastran 2021 software.
- Establishing a regional industry 4.0 electronics hub: The GreenUpPCB modelPublication . Dionísio, Rogério Pais; Ünal, Irem; Delgado-Prieto, M.; Romeral Martinez, L.This chapter presents GreenUpPCB as a regional Industry 4.0 hub for electronics repair and retrofitting, based in Castelo Branco, Portugal. The initiative combines artificial intelligence, machine vision, 3D printing, and automation to extend the life cycle of obsolete printed circuit boards, particularly in renewable energy systems and railway rolling stock. By promoting circular economy practices and reducing electronic waste, GreenUpPCB supports sustainable and resilient industrial operations. The hub also strengthens regional development by linking academic research with industrial needs, offering training, innovation, and high-tech services to local small- and medium-sized enterprises. Its model enables smart manufacturing adoption in low-density territories without dependence on urban clusters. Aligned with the European Chips Act and national strategies for microelectronics, GreenUpPCB demonstrates how regional hubs can contribute to the green and digital transitions across multiple sectors, including energy and transport.