DIGDP-Artículos
URI permanente para esta colecciónhttps://hdl.handle.net/10953/239
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Examinando DIGDP-Artículos por Materia "Additive manufacturing"
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Ítem A numerical and experimental study of the compression uniaxial properties of PLA manufactured with FDM technology based on product specifications(Springer, 2019-04-13) Mercado-Colmenero, Jorge Manuel; Rubio-Paramio, Miguel Ángel; La Rubia-García, María Dolores; Lozano-Arjona, David; Martín-Doñate, CristinaThis paper presents a numerical and experimental study of the compression uniaxial properties of PLA material manufactured with FDM based on product specifications. A first experimental test in accordance with the requirements and conditions established in the ISO 604 standard characterizes the mechanical and elastic properties of PLA manufactured with FDM technology and product requirements in a uniaxial compression stress field by testing six specimens. A second experimental test allows analyzing the structural behavior of the industrial case, evaluating the compression stiffness, the compression yield stress, the field of displacements and stress along its elastic area until reaching the compression yield stress and the ultimate yield stress data. To improve the structural analysis of the case study, a numerical validation was carried out using two analytical models. The first analytical model applies an interpolation procedure to the experimental results of the tested specimens in order to characterize the uniaxial tension-compression curve versus the nominal deformations by means of an 8-degree polynomial function. The second model defines the plastic material as elastic and isotropic with Young's compression modulus constant and according to the guidelines established in ISO standard 604. The comparison between experimental tests and numerical simulation results for the study case verify that the new model that uses the proposed polynomial function is closer to the experimental solution with only an 0.36% error, in comparison with the model with Young's compression modulus constant that reaches an error of 4.27%. The results of the structural analysis of the mechanical element indicate that the elastic region of the plastic material PLA manufactured with FDM can be modeled numerically as an isotropic material, using the elastic properties from the experimental results of the specimens tested according to ISO standard 604. In this way it is possible to characterize the PLA FDM material as isotropic, obtaining as an advantage its easy definition in the numerical simulation software as it does not require the modification of the constitutive equations in the material database. SEM micrographs have indicated that the fracture of the failed test specimens is of the brittle type, mainly caused by the separation between the central plastic filament layers of the specimens. The results presented suggest that the use of FDM technology with PLA material is promising for the manufacture of low volume industrial components that are subject to compression efforts or for the manufacture of components by the user.Ítem Application of new conformal cooling layouts to the green injection molding of complex slender polymeric parts with high dimensional specifications(MDPI, 2023-01-21) Torres-Alba, Abelardo; Mercado-Colmenero, Jorge Manuel; Caballero-García, Juan-de-Dios; Martín-Doñate, CristinaEliminating warpage in injection molded polymeric parts is one of the most important problems in the injection molding industry today. This situation is critical in geometries that are particularly susceptible to warping due to their geometric features, as occurs with topologies of great length and slenderness with high changes in thickness. These features are, in these special geometries, impossible to manufacture with traditional technologies meeting the dimensional and sustainable requirements of the industry. The paper presents an innovative green conformal cooling system that is specifically designed for parts with slender geometric shapes, highly susceptible to warping. Additionally, the work presented by the authors investigates the importance of using highly conductive inserts made of steel alloys in combination with the use of additively manufactured conformal channels in reducing influential parameters such as warpage, cooling time and residual stresses in the complex manufacturing of long and slender parts. The results for a real industrial case study indicate that the use of conformal cooling layouts decreases cycle time by 175.1 s - 66% below the current cooling time, the temperature gradient by 78.5% specifically 18.16 ºC, the residual stress by 39.78 MPa or – 81.88 %, and the warpage by 6.9 mm or- 90.5%. In this way, it is possible to achieve a final warping in the complex geometry studied of 0.72 mm under the maximum value required at the industrial level of 1 mm. The resulting values obtained by the researchers present a turning point from which the manufacturing and sustainability in injection molding of said plastic geometries is possible, taking into account that the geometric manufacturing features 30 analyzed, will present a great demand in the coming years in the auto parts manufacturing industryÍtem PARAMETRIC DESIGN AND ADAPTIVE SIZING OF LATTICE STRUCTURES FOR 3D ADDITIVE MANUFACTURING(FEDERACION ASOCIACIONES INGENIEROS INDUSTRIALES ESPANAALAMEDA DE MAZARREDO, BILBAO 69-48009, SPAIN, 2025-01) Mercado-Colmenero, Jorge Manuel; Diaz-Perete, Daniel; Rubio-Paramio, Miguel Angel; Martin-Doñate, CristinaThe present research is developed into the realm of industrial design engineering and additive manufacturing by introducing a parametric design model and adaptive mechanical analysis for a new lattice structure, with a focus on 3D additive manufacturing of complex parts. Focusing on the land-scape of complex parts additive manufacturing, this research proposes geometric parameterization, mechanical adaptive sizing, and numerical validation of a novel lattice structure to optimize the final printed part volume and mass, as well as its structural rigidity. The topology of the lattice structures exhibited pyramidal geometry. Complete parameterization of the lattice structure ensures that the known geometric parameters adjust to defined restrictions, enabling dynamic adaptability based on its load states and boundary conditions, thereby enhancing its mechanical performance. The core methodology integrates analytical automation with mechanical analysis by employing a model based in two-dimensional beam elements. The dimensioning of the lattice structure is analyzed using rigidity models of its sub-elements, providing an evaluation of its global structural behavior after applying the superposition principle. Numerical validation was performed to validate the proposed analytical model. This step ensures that the analytical model defined for dimensioning the lattice structure adjusts to its real mechanical behavior and allows its validation. The present manuscript aims to advance additive manufacturing methodologies by offering a systematic and adaptive approach to lattice structure design. Parametric and adaptive techniques foster new industrial design engineering methods, enabling the dynamic tailoring of lattice structures to meet their mechanical demands and enhance their overall efficiency and performance.