Auxetic laminates, i.e. with a negative Poisson’s ratio (NPR), show great engineering promise, enhancements in shear resistance, fracture toughness, energy absorption, and delamination damage extension limitation. This study focuses on the tensile properties of in-plane (IP) NPR fibre-reinforced polymer (FRP) namely carbon/epoxy (C/E) carbon-glass/epoxy (C-G/E) lay-up sequences which maximised effect. An analytical was conducted to achieve maximum sequences. Laminates were manufactured via...

Abstract This paper describes a new interleaving methodology to improve composite laminates' low velocity impact (LVI) damage resistance. The approach relies on analyzing interlaminar stress in conventional aircraft laminate determine the appropriate strategy. A model was built identify larges stress, and two strategies were defined, normal shear stress. Four thin veils used validate strategies. Non‐ interleaved laminates submitted LVI tests at 13.5, 25 40 (J) of energy. Despite revealed an...

Three novel Bouligand inspired composites were produced by vacuum bag infusion manufacturing process and their quasi-static mechanical performance compared to a conventional aircraft laminate. A morphologic/physical study was first conducted for all configurations response under tensile, three-point bending (3-PB) interlaminar shear strength (ILSS) tests then evaluated discussed. No significant number of voids detected into laminates, however, rough poor defined region observed in both...

Continuous glass/polypropylene (GF/PP) commingled fiber tapes were employed to produce wrapped pressure gas vessels for domestic applications by using filament winding. The vessel structural-wall was built a hybrid solution consisting in very thin steel liner over the wounded GF/PP tape layers. FEM analysis used evaluate if composite based on (steel + glass reinforced thermoplastic) is capable withstand following requirements: metallic liner, alone, minimum burst of 4MPa and whole minima...

The CPGC – Cork-Polyurethane Gel Composite is a material that mechanically characterized by non-linear elastic behaviour at large deformations. can be modelled hyperelastic constitutive models based on strain energy functions enabling structured phenomenological framework for modelling. promising human comfort enhancement and dynamic damping/control applications. This paper presents the experimental methodology used evaluation of parameters in finite element model build-up. A 3D foot FEA...

Abstract The control of microstructure development in injection molding had attracted several important studies the recent years, being well established that thermo-mechanical environment imposed to polymer melt depends on material properties, geometry and processing conditions. An entirely new design an mold RCEM (Rotation, Compression Expansion Mold) was developed implemented, allowing for a wide variation filling packing conditions flat disk geometry. One cavity walls (the ejection side)...

Abstract Summary: The aim of this study was to design new soy protein‐based bi‐layered co‐injection moulded matrix systems aimed achieve controlled drug delivery. devices consisted a drug‐free outer layer (skin) and drug‐containing core. overcame the inherent disadvantage non‐linear release associated with diffusion‐controlled single‐layer by providing additional releasing area time compensate for decreasing rate. As expected, bi‐layer presented significant decrease in rate when compared...

The present work aims at determining the critical material properties that can be used to tailor crush behaviour of pultruded GFRP (Glass Fibre Reinforced Polymer) box-beams, as found in, for example, roadside furniture such guard-rails. For this purpose, mechanical and energy absorption mechanisms constituent box-beam sections subjected lateral compressive loading, dominating load case in composite structures when furniture, have been studied. analysed profiles consist E-glass fibre...

Operational Program of Competitiveness and Internationalization (POCI), Lisbon Operational Program, with support from the European Regional Development Fund (FEDER), Foundation for Science Technology I. P, State Budget – OE, under project no. 016893, entitle “Development of Auxetic Fibrous Composite for Personal Protection (POCI-01-0145-FEDER-016893 and PTDC/CTM-POL/5814/2014)

A special tool-transparent mould designed to visualize the melt flow inside cavity is used in this research. The aim of work assess polymer behavior under different processing conditions-close industrial, conventional and two materials non-conventional injection moulding techniques. with locations has possibility change geometry order investigate differently shaped cavities. Visual access allowed by sapphire windows, surrounding cavity. For image acquisition a high speed video camera NAC...

We have employed molecular dynamics simulations to study the behavior of virtual polymeric materials under an applied uniaxial tensile load. Through computer simulations, one can obtain experimentally inaccessible information about phenomena taking place at and microscopic levels. Not only global material response be monitored characterized along time, but macromolecular chains followed independently if desired. The computer-generated were created by emulating step-wise polymerization,...

Background: Aiming to foster a discussion on the provision of public self-services citizens through e-gov platforms, this study seeks to: gain an overview self-service for individual income tax declarations in 2019 and 2023, comparing platforms countries ranked with highest UN e-participation indices. Materials Methods: This research adopts qualitative, quantitative, exploratory, retrospective approaches. The analysis was conducted repeated rigorously investigating portals 54 indices by...

Background: In the administration field, organizations, whether private or public, need to maintain relationships with their stakeholder groups through communication. Among various channels available today, a website serves as strategic option, functioning both communication tool and self-service platform for users. Within this context, it is necessary investigate perception of citizen stakeholders regarding Regional Electoral Court Minas Gerais – Brazil (TRE-MG) service portal. Materials...

Objective: It aims to present the patient’s electronic medical record as a digital tool with great potential for structuring construction of individual’s clinical history and how it can help throughout care process. This also refers its use in COVID-19 Pandemic, but this presents ethical, moral legal problems that will be discussed. Methodology: bibliographic review or survey literature, which is way gain knowledge different scientific contributions provide elements study. Results: was shown...

This paper reports the development of novel auxetic fibrous structures from high performance yarns using knitting technology for application as reinforcement in composites. Two types yarns, namely, para-aramid (p-AR) and polyamide 6.6 (PA), were used to produce three distinct structures: purl, re-entrant lozenge star structures. It was observed that all produced could achieve maximum negative Poisson's ratios (NPR) -0.60, -0.54 -0.47 course direction purl wale structures, respectively. The...

A highly effective Structural Health Monitoring, SHM, system for aerospace applications must be, besides reliable, a low complexity and weight solution. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1,2</sup> This can be achieved with reduced number of sensors, which normally implies resolution mapping the monitored variables and, consequently, weakness on diagnosis prognosis procedures. To overcome these difficulties, physical information...