Nonintrusive parametric solutions in structural dynamics

© 2022 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/A nonintrusive reduced order method able to solve a parametric modal analysis is proposed in this work. The main objective is being able to efficiently identify how a variation of user-defined parameters affects the dynamic response of the structure in terms of fundamental natural frequencies and corresponding mode shapes. A parametric version of the inverse power method (IPM) is presented by using the proper generalised decomposition (PGD) rationale. The proposed approach utilises the socalled encapsulated PGD toolbox and includes a new algorithm for computing the square root of a parametric object. With only one offline computation, the proposed PGD-IPM approach provides an analytical parametric expression of the smallest (in magnitude) eigenvalue (or natural frequency) and corresponding eigenvector (mode shape), which contains all the possible solutions for every combination of the parameters within pre-defined ranges. A Lagrange multiplier deflation technique is introduced in order to compute subsequent eigenpairs, which is also valid to overcome the stiffness matrix singularity in the case of a free-free structure. The proposed approach is nonintrusive and it is therefore possible to be integrated with commercial finite element (FE) packages. Two numerical examples are shown to underline the properties of the technique. The first example includes one material and one geometric parameter. The second example shows a more realistic industrial example, where the nonintrusivity of the approach is demonstrated by employing a commercial FE package for assembling the FE matrices. Finally, a multi-objective optimisation study is performed proving that the developed method could significantly assist the decision-making during the preliminary phase of a new design process.This project is part of the Marie Skłodowska-Curie ITN-EJD ProTechTion funded by the European Union Horizon 2020 research and innovation program with Grant Number 764636. The work of Fabiola Cavaliere, Sergio Zlotnik and Pedro Díez is partially supported by the MCIN/AEI/10.13039/501100011033, Spain (Grant Number: PID2020-113463RB-C32, PID2020-113463RB-C33 and CEX2018-000797-S). Ruben Sevilla also acknowledges the support of the Engineering and Physical Sciences Research Council (Grant Number: EP/P033997/1).Peer ReviewedPostprint (author's final draft

Nonintrusive parametric NVH study of a vehicle body structure

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Mechanics based design of structures and machines on 27/06/22, available online at: http://www.tandfonline.com/10.1080/15397734.2022.2098140A reduced order model technique is presented to perform the parametric Noise, Vibration and Harshness (NVH) study of a vehicle body-in-white (BIW) structure characterized by material and shape design variables. The ultimate goal is to develop a methodology which allows to efficiently explore the variation in the design space of the BIW static and dynamic global stiffnesses, such that the NVH performance can be evaluated already in the preliminary phase of the development process. The proposed technique is based on the proper generalized decomposition (PGD) method. The obtained PGD solution presents an explicit dependency on the introduced design variables, which allows to obtain solutions in 0.1 milliseconds and therefore opens the door to fast optimization studies and real-time visualizations of the results in a pre-defined range of parameters. The method is nonintrusive, such that an interaction with commercial software is possible. A parametrized finite element (FE) model of the BIW is built by means of the ANSA CAE preprocessor software, which allows to account for material and geometric parameters. A comparison between the parametric NVH solutions and the full-order FE simulations is performed using the MSC-Nastran software, to validate the accuracy of the proposed method. In addition, an optimization study is presented to find the optimal materials and shape properties with respect to the NVH performance. Finally, in order to support the designers in the decision-making process, a graphical interface app is developed which allows to visualize in real-time how changes in the design variables affect pre-defined quantities of interest.This project is part of the Marie Skłodowska-Curie ITN-EJD ProTechTion funded by the European Union Horizon 2020 research and innovation program with Grant Number 764636. The work of Fabiola Cavaliere, Sergio Zlotnik and Pedro D ıez is partially supported by the MCIN/AEI/10.13039/501100011033, Spain (Grant Number: PID2020-113463RB-C32, PID2020-113463RB-C33 and CEX2018-000797-S). Ruben Sevilla also acknowledges the support of the Engineering and Physical Sciences Research Council (Grant Number: EP/T009071/1).Peer ReviewedPostprint (published version

Study of the Phenolic Compound Profile of Arbutus unedo L. Fruits at Different Ripening Stages by HPLC-TQ-MS/MS

Arbutus unedo L. berries have traditionally been used as edible and medicinal fruits in folk medicine for the treatment of some pathologies. Besides their good nutritional properties, these berries are rich in bioactive compounds. Accordingly, a HPLC-triple quadrupole (TQ)-MS/MS method was developed and validated for the first time to characterize the changes produced in the phenolic composition profile of A. unedo L. fruits through three ripening stages. Several hydroxycinnamic and hydroxybenzoic acids were detected, gallic acid being the highest phenolic acid quantified. Quercetin, quercetin-3-β-glucoside, rutin, and kaempferol were found in similar amounts at the different maturity stages. High amounts of (+)-catechin, procyanidin B2, epigallocatechin, and (−)-epigallocatechin gallate were observed in the unripe fruits. Naringin and vitexin were also quantified. Stilbenes, such as trans-resveratrol and trans-piceid, were identified for the first time in these fruits. Total phenolic compounds, total anthocyanin compounds, and radical scavenging activity were also determined in the fruits harvested at different years in several locations of the Iberian Peninsula at different ripening stages. The results confirmed that these fruits are an excellent source of these bioactive compounds (mainly flavanols) with high antioxidant activity, which could be used as a new source for preparation of nutraceutical or functional foods

Estudio de los procesos de migración de bisfenol A (BPA) en envases alimentarios de uso doméstico

Peer reviewe

Study of plasticizer migration processes from domestic containers used for storage and processing

Trabajo presentado al EURO FOOD CHEM XVIII, celebrado en Madrid los días 13 a 16 de octubre de 2015Food products are produced and distributed worldwide, so leading to very stringent regulations to guarantee food quality safety. Comparison of the various sources of food contamination with organic chemicals suggests that among the public, but also among experts, the perception of risk is often distorted. Therefore, if you ask educated consumers about the principal source of food contamination they will list pesticides as the first item, just few of them would even mention food-packaging materials, although the amount of material migrating from food packaging into food may well be 100 times greater than the contribution of pesticides or environmental pollutants [1]. Plasticizers have been described as being among the most abundant man-made environmental pollutants. Among them, phthalates and other plasticizers have been focus at several surveys and exposure assessments. In addition, bisphenols, such as bisphenol A (BPA), and their derivates with epoxy or clorohydrin groups are known to be endocrine disruptors in humans as well as being potentially carcinogenic [2]. A rapid and sensitive analytical method based on ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) has been developed for the determination of different food contaminant coming from packaging materials. All the analyses were performed using an Acquity UPLC© BEH Phenyl column (2.1 mm x 50 mm, 1.7 μm, Waters), and the compounds were subsequently analyzed by a Xevo© TQ-S triple quadrupole mass spectrometer (Waters) using an electrospray ionization (ESI) interface. Optimal UHPLC-MS conditions were selected based on sensitivity, selectivity and reproducibility terms. Two transitions for each analyte and isotopically labeled internal standard were monitored in multiple reaction monitoring (MRM) mode. Specific transitions from different precursor to several product ions were studied and the most abundant one was chosen for quantification and the second most abundant for confirmation. This methodology was applied to the study of the influence of main domestic parameter related to storing and cooking such as time, temperature and plastic type material. The results show a clear relationship of dependence between these three experimental parameters and phenomena of migration of this type of contaminants from the container. For doing these experiments, the different food simulants established in the Official Journal of European Union [3] were employed. Acknowledgments Spanish Ministry of Economy and Competitiveness (project AGL2012-37201) JCCM (Postdoctoral contract Resolución de 08/08/2014) References: (1) Gallarta-Ayala H, Núñez O, Lucci P. (2013) Recent advances in LC-MS analysis of food-packaging contaminants. TRAC-Trends Anal Chem 42, 99-124. (2) Poças MF, Hogg T. (2007) Exposure assessment of chemicals from packaging materials in foods: a review. Trends Food Sci Tech 18, 219-230. (3) COMMISSION REGULATION (EU) No 10/2011of 14 January 2011. Official Journal of European Union.Acknowledgments Spanish Ministry of Economy and Competitiveness (project AGL2012-37201) JCCM (Postdoctoral contract Resolución de 08/08/2014)Peer reviewe

Study of the Phenolic Compound Profile of <i>Arbutus unedo</i> L. Fruits at Different Ripening Stages by HPLC-TQ-MS/MS

Arbutus unedo L. berries have traditionally been used as edible and medicinal fruits in folk medicine for the treatment of some pathologies. Besides their good nutritional properties, these berries are rich in bioactive compounds. Accordingly, a HPLC-triple quadrupole (TQ)-MS/MS method was developed and validated for the first time to characterize the changes produced in the phenolic composition profile of A. unedo L. fruits through three ripening stages. Several hydroxycinnamic and hydroxybenzoic acids were detected, gallic acid being the highest phenolic acid quantified. Quercetin, quercetin-3-β-glucoside, rutin, and kaempferol were found in similar amounts at the different maturity stages. High amounts of (+)-catechin, procyanidin B2, epigallocatechin, and (−)-epigallocatechin gallate were observed in the unripe fruits. Naringin and vitexin were also quantified. Stilbenes, such as trans-resveratrol and trans-piceid, were identified for the first time in these fruits. Total phenolic compounds, total anthocyanin compounds, and radical scavenging activity were also determined in the fruits harvested at different years in several locations of the Iberian Peninsula at different ripening stages. The results confirmed that these fruits are an excellent source of these bioactive compounds (mainly flavanols) with high antioxidant activity, which could be used as a new source for preparation of nutraceutical or functional foods

A nonintrusive reduced order method for the NVH assessment and automotive structural dynamics

The goal of this work is to develop a computational method able to optimize the design process of a car structure and provide a tool which can support designers during the decision-making phase. The design of a car body-in-white (BIW) structure is the process which goes from the initial idea to the final approved model. During this phase, which represents the most time-consuming part of the whole development process, designers have to deal with very complex parametric problems where material and geometric characteristics of the car components are the unknown. Any change in these parameters might significantly affect the global behaviour of the car. A target which is very sensitive to small variations of the parameters is the noise and vibration response of the vehicle (NVH test), which strictly depends on the global static and dynamic stiffness. In order to find the optimal solution, a lot of configurations exploring all the possible parametric combinations need to be tested. Standard numerical methods are computationally very expensive when applied to this kind of multidimensional problems. An alternative is represented by reduced order models (ROM), which are based on the idea that the essential behaviour of complex systems can be accurately described by simplified low-order models. In this work, the encapsulated proper generalized decomposition (Encapsulated-PGD) toolbox, based on the PGD Least-Squares approximation [3] is proposed. As a main advantage, this ROM technique requires only one offline computation. The latter provides a separable solution which depends explicitly on an a-priori unknown number of parametric and mechanic modes or snapshots. Then, during an online stage, the solution can be particularized in realtime for any set of the parameters. In a previous work [4], a coupling of the PGD method with the Inertia Relief technique was implemented in order to perform the parametric static analysis of an unconstrained structures. A novel algebraic approach allowed to incorporate both material and complex geometric parameters and to perform shape optimization. Here, the method is extended to the case of a parametric generalized eigenvalue problem, in order to identify how a variation of user-defined parameters affects the dynamic response of the structure in terms of dominant eigenmodes and related natural frequencies. Moreover, thanks to the nonintrusive format of the toolbox, an interaction with commercial software is possible, which makes it particularly interesting for real industrial applications.Peer ReviewedPostprint (author's final draft

Metodologías activas coordinadas aplicadas en asignaturas de segundo curso del Grado en Ciencia y Tecnología de los Alimentos

En este trabajo se presentan dos experiencias de gamificación que se han realizado de manera coordinada entre tres asignaturas de segundo curso del Grado en Ciencia y Tecnología de los Alimentos (CyTA) de la Universidad Rey Juan Carlos durante el curso 2022-2023. Las actividades fueron una yincana con retos encadenados desarrollada en aula y laboratorio y la visualización de videos con experimentos para la resoluciones de cuestiones. La buena valoración por parte del estudiantado y la consecución de los objetivos en lo que respecta al aumento de su motivación por los estudios, la asimilación de conceptos teórico-prácticos y la mejora en las tasas de superación de las asignaturas implicadas confirman la idoneidad del uso de metodologías activas coordinadas en el ámbito universitario