DIGDP-Artículos

URI permanente para esta colecciónhttps://hdl.handle.net/10953/239

Examinar

Mostrando 1 - 8 de 8

A novel geometric predictive algorithm for assessing Compressive Elastic Modulus in MEX additive processes, based on part nonlinearities and layers stiffness, validated with PETG and PLA materials
(Elsevier, 2024-04) Mercado-Colmenero, Jorge Manuel; Martin-Doñate, Cristina
MEX (Material Extrusion) is an intrusive technological process that inherently induces alterations in the elastic and mechanical parameters of plastic materials. Manufacturers provide initial mechanical parameters for plastic filaments, which undergo modifications during MEX manufacturing, influenced by intrinsic manufacturing factors such as temperature and pressure changes, as well as geometric and technological parameters of the 3D additive process. These factors, compounded by the inherent geometric nonlinearities in plastic components, directly impact the post-manufacture mechanical and elastic properties of the material. Presently, material characterization in MEX manufacturing relies on manual experimental testing, necessitating new tests for any variation in manufacturing parameters. In this scenario of mechanical uncertainty, rigorously validating component behavior involves costly experimental trials. Intending to solve the problems of MEX components manufacturing, the paper presents an innovative methodology based on the use of a new predictive algorithm created by the researchers capable of obtaining the elastic modulus of a plastic material manufactured with MEX and its mechanical behaviour in the elastic zone under compressive loads. The predictive algorithm only needs as input the compressive elastic modulus of the isotropic plastic material filament and the manufacturing parameters of the MEX process. The smart developed algorithm calculates the stiffness of each layer considering the number of holes in the projected area. The innovative predictive algorithm has been experimentally and numerically validated using PETG (Polyethylene Terephthalate Glycol) material and PLA (Polylactic Acid) on test specimens and on a case study of variable topology. The results show deviations from [0.2% – 4.3%] for PETG and [0.4%] for PLA concerning the experimental tests and [1.1%-13.5%], to the numerical analyses. In this line, the presented algorithm greatly improves the results obtained by the simulation software since this software currently can not consider the geometric and technological parameters associated with the 3D manufacturing process of the component. The predictive algorithm is valid for each print pattern and manufacturing direction. The new algorithm improves the existing state of the art significantly since this algorithm extends its utility to most plastic polymer materials suitable for MEX 3D printing, provided that the mechanical and elastic properties of the filament are known. Its versatility extends to complex component geometries subjected to uniaxial compression loads, eliminating the need for mechanical analysis software or expensive experimental validations.
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-Garcia, Juan de Dios; Martin-Doñate, Cristina
Eliminating 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 industry
Energy Recovery from Polymeric 3D Printing Waste and Olive Pomace Mixtures via Thermal Gasification—Effect of Temperature
(MDPI, 2023-02) Diaz-Perete, Daniel; Hermoso-Orzaez, Manuel Jesus; Carmo-Calado, Luis; Martin-Doñate, Cristina; Terrados-Cepeda, Julio
One of the polymeric materials used in the most common 3D printers is poly(ethylene terephthalate) glycol (PETG). It represents, in world terms, around 2.3% of polymeric raw material used in additive manufacturing. However, after processing this material, its properties change irreversibly. A significant amount of waste is produced around the world, and its disposal is usually destined for landfill or incineration, which can generate an important issue due to the high environmental risks. Polymer waste from 3D printing, hereinafter 3DPPW, has a relatively high calorific value and adequate characteristics to be valued in thermochemical processes. Gasification emerges as an innovative and alternative solution for recovering energy from 3DPPW, mixed with residues of lignocellulosic origin, and presents some environmental advantages compared to other types of thermochemical treatments, since the gasification process releases smaller amounts of NOx into the atmosphere, SOx, and CO2. In the case of the study, co-gasification of olive pomace (OLB) was carried out with small additions of 3DPPW (10% and 20%) at different temperatures. Comparing the different gasifications (100% OLB, 90% OLB + 10% 3DPPW, 80% OLB + 20% 3DPPW), the best results for the synthesis gas were obtained for the mixture of 10% 3DPPW and 90% olive pomace (OLB), having a lower calorific value of 6.16 MJ/m(3), synthesis gas yield of 3.19%, and cold gas efficiency of 87.85% for a gasification temperature of 750 degrees C. In addition, the results demonstrate that the addition of 3DPPW improved the quality of syngas, especially between temperatures of 750 and 850 degrees C. Including polymeric 3D printing materials in the context of the circular economy and extending their life cycle helps to improve the efficiency of subsequent industrial processes, reducing process costs in general, thanks to the new industrial value acquired by the generated by-products.
Enhancing complex injection mold design validation using 2 multicombined RV environments
(MDPI, 2024-04) Mercado-Colmenero, Jorge Manuel; Garcia-Molina, Diego Francisco; Gutierrez-Jimenez, Bartolomé; Martin-Doñate, Cristina
The intricate design of real complex injection molds poses significant challenges. Mold design validation often falls to operators with tool-handling experience but limited CAD proficiency. Unlike other industries, the scale and costs of injection mold fabrication hinder prototyping before production. Virtual reality (VR) has emerged as a revolutionary solution offering a safe, immersive, and realistic experience and accessible using QR codes. This paper presents a new multimodal virtual environment tailored to validate mold design complexities. Integrating knowledge-enriched visual tools like interactive 3D models and dynamic visualizations enables users to explore complex mold designs. Statistical analyses, including the Wilcoxon test, unveil significant differences in interference detection, internal topology tracking, and validation of assembly and disassembly accessibility for both small and large mold components when comparing validation conducted through traditional means using solely CAD systems versus the utilization of multidimensional validation methods. Efficiency gains in using VR devices for mold design validation in a hybrid environment in the analysis of relative frequencies. The present study surpasses the state of the art illustrating how VR technology can substantially reduce manufacturing errors in injection molding processes, thereby offering important advantages for manufacturers emerging as an essential tool for this impact industry in the next years.
Methodology for intelligent plastic injection point location based on geometric algorithms and discrete topologies for virtual digital twin environments
(FEDERACION ASOCIACIONES INGENIEROS INDUSTRIALES ESPANAALAMEDA DE MAZARREDO, BILBAO 69-48009, SPAIN, 2014-01) Mercado-Colmenero, Jorge Manuel; Torres-Alba, Abelardo; Martin-Doñate, Cristina
Implementing intelligent design models can revolutionize the use of digital twins, which are crucial in product design by incorporating intelligent algorithms. This perspective is especially important for the design of injection-molded plastic parts, a complex process that often requires expert knowledge and costly simulation software not available to all companies. This article presents an innovative methodology for locating injection points in injection-molded parts using intelligent models with geometric algorithms for discrete topologies. The first algorithm calculates the center of mass of the discrete model based on the center of mass of each triangular facet in the system, ensuring uniform molten plastic distribution during mold cavity filling. Two sub-algorithms intelligently evaluate the geometry and optimal injection point location. The first sub-algorithm generates a geometric matrix based on a two-dimensional nodal quadrature adapted to the part's bounding box. The second sub-algorithm projects the nodal matrix and associated circular areas orthogonally on the part's surface along the demolding direction. The optimal injection point location is determined by minimizing the distance to the center of mass from the first algorithm's result. This novel methodology has been validated through rheological simulations in six case studies with complex geometries. The results demonstrate uniform and homogeneous molten plastic distribution with minimal pressure loss during the filling phase. Importantly, this methodology does not require expert intervention, reducing time and costs associated with manual injection mold feed system design. It is also adaptable to various design environments and virtual twin systems, not tied to specific CAD software. The validated results surpass the state of the art, offering an agile alternative for digital twin applications in new product design environments, reducing dependence on experts, facilitating designer training, and ultimately cutting costs
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, Cristina
The 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.
Using numerical-experimental analysis to evaluate rPET mechanical behavior under compressive stresses and MEX additive manufacturing for new sustainable designs
(Emerald Publishing, 2023-07-26) Mercado-Colmenero , Jorge Manuel; La Rubia, M.Dolores; Mata-Garcia, Elena; Rodriguez-Santiago, Moises; Martin-Doñate, Cristina
Purpose: Because of the anisotropy of the process and the variability in the quality of printed parts, finite element analysis is not directly applicable to recycled materials manufactured using fused filament fabrication. This study investigates the numerical-experimental mechanical behavior modeling of the recycled polymer rPET manufactured by MEX (Material Extrusion) process under compressive stresses for new sustainable designs. Design/Methodology: Forty-two test specimens were manufactured and analyzed according to the ASTM D695-15 standards. Eight numerical analyzes were performed on a real design manufactured with rPET using Young's compression modulus from the experimental tests. Finally, eight additional experimental tests under uniaxial compression loads were performed on the real sustainable design for validating its mechanical behavior versus computational numerical tests. Findings: As a result of the experimental tests, rPET behaves linearly until it reaches the elastic limit, along each manufacturing axis. The results confirmed the design's structural safety by the load scenario and operating boundary conditions. Experimental and numerical results show a difference of 0.001 mm to 0.024 mm, allowing for the rPET to be configured as isotropic in numerical simulation software without having to modify its material modeling equations. Practical implications: The results obtained are of great help to industry, designers, and researchers because they validate the use of recycled rPET for the ecological production of real-sustainable products using MEX technology under compressive stress and its configuration for numerical simulations. Major design companies are now using recycled plastic materials in their high-end designs. Originality: Validation results have been presented on test specimens and real ítems, comparing experimental material configuration values with numerical results. Specifically, no industrial or scientific work has been conducted with rPET subjected to uniaxial compression loads for characterizing experimentally and numerically the material using these results for validating a real case of a sustainable industrial product
WEEE polymers valorization, its use as fuel in the gasification process and revaluation of the inert by-products obtained: Sustainable mortars as a solution
(Cell Press, 2023-09) Diaz-Perete , Daniel; Hermoso-Orzaez, Manuel Jesus; Terrados-Cepeda, Julio; Silva-Romano, Pedro; Martin-Doñate, Cristina
The global production of polymer materials has exploded in the last few decades. Their mechanical properties, erosion and corrosion resistance, good performance as insulation materials, and their ease and flexibility of manufacturing have made polymers one of the most widely used materials in the industry and in daily life. Several institutions and governments are beginning to raise serious environmental and ecological concerns with international impact soon, due to the increasing level of polymer production, which does not seem to be slowing down. It is necessary for the scientific community to make efforts in the development and evaluation of new methodologies to enable the inclusion of these types of materials in the circular economy of various production sectors. This is important in order to reduce the ecological impact caused by the current global production level of polymers. One of the most used methods for the recovery of polymeric materials is energy valorization through thermochemical processes. An example of this is thermal gasification using fuels composed of biomass and a mixture of polymeric waste from electrical and electronic equipment (WEEE). Through this thermochemical process, high-energy value synthesis gas, with a high concentration of hydrogen, is obtained on one hand, while waste products in the form of chars, ashes and slag are generated on the other hand. This manuscript presents a detailed study methodology that begins with chemical analysis of the raw material and includes subsequent analysis of mechanical results for the revaluation of these residual inert by-products, using them as partial substitutes in cement clinker to produce building mortars. This described methodology influences directly in the LCC (Life Cycle Costing) of final designed products in plastic and extend material life cycle Plastic materials are here to stay, so the study and optimization of polymer waste recovery processes are vital in achieving the Sustainable Development Goals (SDGs) set by the European Union in terms of efficiency and sustainability. It is also the only possible way to create an environmentally sustainable future world for future generations. After applying the described methodology, the mechanical test results show that the modified mortars exhibit established behaviour during the hardening time and similar strength growth compared to commercial mortars. The maximum mechanical strengths achieved,including compressive and flexural strength, make modified mortars a viable choice for several applications in the civil engineering sector.

RUJA: Repositorio Institucional de Producción Científica

Examinar

Examinando DIGDP-Artículos por Materia "6"