Documents published in Scipedia

• Influence of sample position on stress monitoring in composite materials using magnetic microwires.

  R. Garcia-Etxabe, M. Mendinueta, M. Camacho-Iglesias, J. Vallejo, A. Zhukov, V. Zhukova

  Materiales Compuestos (Online first).

  
  

  Abstract

  Soft magnetic materials are excellent candidates as sensors for monitoring materials, applications and processes, having already found application in multiple sectors. Moreover, their ability to be configured as microwires ensures excellent integration within composite structures, making them ideally suited for reinforced material monitoring. At GAIKER, within the INFINITE and MOSINCO projects, required equipment and characterization techniques have been developed to evaluate the behavior of electromagnetic properties under various stimuli (stress, temperature...) These investigations have enabled the analysis of both hysteresis loops and scattering parameters in transmission and reflection within the microwave range, under conditions such as composite matrix polymerization or when subjecting specimens to different stress states. Consequently, a clear dependency of scattering parameters and impedance on applied stress, which can be monitored, has been demonstrated. However, despite the repeatability of the phenomenon, modeling this behavior is challenging due to the dispersion of results caused by multiple factors and varying conditions that influence outcomes in a conventional environment. This study analyzes the influence of the relative sample position on these measurements and presents results obtained by modifying the position and orientation of microwires through rotation and flipping movements of the test specimen.

  Abstract
  Soft magnetic materials are excellent candidates as sensors for monitoring materials, applications and processes, having already found application in multiple sectors. Moreover, [...]

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• Determination of curing times in an ultraviolet curing composites manufacturing process

  J. Vallejo, I. Avila, A. Uriarte

  Materiales Compuestos (2023). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 2 - Fabricación y Aplicaciones Industriales - Sostenibilidad y Reciclaje.), 33

  
  

  Abstract

  Currently, the manufacture of fiberglass composite parts for the automotive industry is limited by the curing times of the resins. The curing of this type of parts is usually done at room temperature, which entails waiting times of up to 48 hours. The purpose of this study is to analyse the curing times of the pieces made with ultraviolet curing resin to replace the conventional temperature curing. In the case of ultraviolet radiation curing, the geometry of the part has a significant importance in curing times. To carry out this study, the UV lamp has been characterized to determine the irradiance at different distances. Once the irradiance is obtained as a function of the distance, the curing time of the prepreg test tubes was determined by means of a dielectric analysis (DEA). As a result, a mathematical model capable of approximating the curing time of different types of pieces based on their geometry and distance from the spotlight has been obtained. In this way, it is possible to create a strategy that optimizes the process. This process is much more efficient than the hand lay-up (HLU) used up to now, so it could be a good substitute if you want to increase the production of fiberglass composite parts.

  Abstract
  Currently, the manufacture of fiberglass composite parts for the automotive industry is limited by the curing times of the resins. The curing of this type of parts is usually [...]

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