5 documents found, page 1 of 1
Processing and structural health monitoring of a composite overwrapped pressure...
Rocha, Helena Cristina Lopes; Antunes, Paulo; Lafont, Ugo; Nunes, J. P.A process and Structural Health Monitoring system was implemented on a Composite Overwrapped Pressure Vessel (COPV) for hydrogen storage at 350 bar to be used in a fuel-cell system of an Unmanned Aerial Vehicle. This work reports the embedment strategy of optical fibre Bragg grating (FBG) sensors to monitor the full life cycle of the vessel, consisting of an aluminium liner and a wound carbon fibre reinforced p...
Damage localization on CFRP composites by electrical impedance tomography
Rocha, Helena Cristina Lopes; Fernandes, Christophe; Ferreira, Nelson; Lafont, Ugo; Nunes, J. P.This work exploited the use of electrical impedance tomography (EIT) with one-step difference Gaussian-Newton (GN) algorithm to detect different types of damage on unidirectional carbon fibre/epoxy composite laminates. The major challenge concerning the implementation of EIT on composite materials has to do with their anisotropy. To assess this issue, this study was conducted on carbon fibre composites having d...
Electrical impedance tomography for damage detection and localization on carbon...
Rocha, Helena Cristina Lopes; Fernandes, Christophe; Ferreira, Nelson; Lafont, Ugo; Nunes, João P.Electrical impedance tomography (EIT) is being developed as promising non-intrusive technology for damage detection in conductive fibre reinforced polymers (FRP) composites. This work assessed EIT and one-step difference Gaussian-Newton algorithm to detect different damages in CFRP laminates, including through-thickness holes and impact damage of different severities. Two layup laminates were studied: quasi-iso...
Optimisation of through-thickness embedding location of Fibre Bragg grating sen...
Rocha, Helena Cristina Lopes; Lafont, Ugo; Nunes, J. P.Aerospace composites are susceptible to barely visible impact damage (BVID) produced by low-velocity-impact (LVI) events. Fibre Bragg grating (FBG) sensors can detect BVID, but often FBG sensors are embedded in the mid-plan, where residual strains produced by impact damage are lower, leading to an undervaluation of the damage severity. This study compares the residual strains produced by LVI events measured by ...
Electrically conductive polyetheretherketone nanocomposite filaments: from prod...
Gonçalves, Jordana Catarina Carvalho; Lima, Patrícia; Krause, Beate; Pötschke, Petra; Lafont, Ugo; Gomes, José R.; Abreu, Cristiano S.; Paiva, M. C.The present work reports the production and characterization of polyetheretherketone (PEEK) nanocomposite filaments incorporating carbon nanotubes (CNT) and graphite nanoplates (GnP), electrically conductive and suitable for fused deposition modeling (FDM) processing. The nanocomposites were manufactured by melt mixing and those presenting electrical conductivity near 10 S/m were selected for the production of ...