Fire performance assessment of FRP materials

The European FIBRESHIP research project aims to develop a comprehensive set of methods that would enable the building of the complete hull and superstructure of over 50-metre-long ships in fibre reinforced polymer (FRP) materials. In the work package dedicated to materials selection, an extensive experimental campaign is performed to characterize the fatigue and fire performance of a range of FRP materials and solutions. In this paper, the cone calorimetry results of FRP laminates are introduced in terms of ignitability, heat release, smoke production and effective heat of combustion. The fire performance of FRP materials can be considerably improved by suitable intumescent coatings. Coatings can significantly change the shape of the heat release and smoke production rate curves, and reduce their maximum values. Even though fire performance is of high importance in the use of FRP materials, also other properties, such as mechanical properties and manufacturing, need to be taken into account. In some cases, products with excellent fire performance have to be discarded from further considerations due to other issues

Harrastetori:tapahtuman suunnittelu ja toteutus yhdessä kehitysvammaisten opiskelijoiden kanssa

Toteutimme toiminnallisen opinnäytetyömme Yhdessä-hankkeeseen. Hankkeen tavoitteena on kehittää inklusiivista toimintaa erityistä tukea tarvitsevien nuorten ja yleisopetuksen nuorten välillä Helsingin Maunulassa. Osallistuimme Leikkipuisto Maunulassa järjestettyyn Harrastetori-tapahtumaan Haavikon opetus- ja aikuiskasvatuskeskuksen kehitysvammaisten opiskelijoiden kanssa. Harrastetorissa esiteltiin Maunulan alueen erilaisia harrastusmahdollisuuksia. Tapahtuman pääjärjestäjänä toimi moniammatillinen yhteistyöryhmä Maunulatiimi. Maunulatiimi koostuu kasvatus- ja sosiaalialan ammattilaisista. Lisäksi kehitimme tapahtumaa aiempaa inklusiivisemmaksi ja yhteisöllisemmäksi ja etsimme Maunulatiimiin uusia jäseniä. Toimintamme perustui inkluusioon ja voimaantumiseen. Inkluusiossa jokainen yksilö on tasavertainen ja täysivaltainen yhteisön jäsen. Haavikon opiskelijat olivat tapahtuman suunnittelussa ja toteutuksessa tasavertaisia toimijoita. Voimaantuminen on yksilön inhimillisen toimintakyvyn ja henkilökohtaisen hallinnan vahvistumista. Toimintatapamme mahdollistivat opiskelijoiden voimaantumisen. Harrastetorin suunnittelu ja valmistelu toteutettiin kerhomuotoisena toimintana Haavikossa. Kerhokertoja oli viisi ja lisäksi pidimme päätösjuhlan tapahtuman jälkeen. Toimintaan osallistui 11 opiskelijaa. Kerhoissa ideoimme opiskelijoiden kanssa toimintamme sisällön Harrastetoria varten, harjoittelimme ohjaustehtäviä ja askartelimme koristeita ja tarvikkeita tapahtumaan. Harrastetorissa toteutimme tanssia, tarkkuuslajeja ja taitoradan. Haavikon opiskelijat olivat tapahtumassa aktiivisia ohjaajia ja hoitivat tehtäviään itsenäisesti. Suunnittelimme toimintamme sellaiseksi, että kaikilla tapahtumaan osallistujilla oli mahdollisuus osallistua siihen. Tapahtumaan osallistui muitakin kehitysvammaisia, mikä teki tapahtumasta inklusiivisemman. Saimme Haavikon jäseneksi Maunulatiimiin ja yhden entisen jäsenen palaamaan takaisin tiimin toimintaan

Improved Fire Retardancy of Cellulose Fibres via Deposition of Nitrogen-Modified Biopolyphenols

Driven by concerns over the health and environmental impacts of currently used fire retardants (FRs), recent years have seen strong demand for alternative safer and sustainable bio-based FRs. In this paper, we evaluated the potential of nitrogen-modified biopolyphenols as FRs for cellulosic natural fibres that could be used in low-density cellulose insulations. We describe the preparation and characterisation of nitrogen-modified lignin and tannin containing over 10% nitrogen as well as the treatment of cellulose pulp fibres with combinations of lignin or tannin and adsorption-enhancing retention aids. Combining lignin or tannin with a mixture of commercial bio-based flocculant (cationised tannin) and anionic retention chemical allowed for a nearly fourfold increase in lignin adsorption onto cellulosic pulp. The nitrogen-modified biopolyphenols showed significant improvement in heat release parameters in micro-scale combustion calorimetry (MCC) testing compared with their unmodified counterparts. Moreover, the adsorption of nitrogen-modified lignin or tannin onto cellulose fibres decreased the maximum heat release rate and total heat release compared with cellulose reference by 15–23%. A further positive finding was that the temperature at the peak heat release rate did not change. These results show the potential of nitrogen-modified biopolyphenols to improve fire-retarding properties of cellulosic products

Effect of sprinklers on the patient's survival probability in hospital room fires

The effectiveness of sprinklers in protecting a patient in a hospital room fire was investigated by performing 26 sprinklered and four free-burn experiments in real hospital rooms equipped with water-based automatic suppression system. Three different fire loads were used: UL 1626 corner test fire and two different textile fires. The measurements included temperatures, pipe pressure, and concentrations of about 20 different gas compounds. Based on the measurement results, we calculated the Fractional Effective Dose (FED) and Fractional Irritant Concentration (FIC) –values, and estimated the likelihood of incapacitation as a function of time. The results showed that sprinklers maintained temperatures at low level and reduced toxicity, mainly through fire development control. In UL1626 and large textile fires, sprinklers decreased the patient's incapacitation probability from 0.9 or above to the level of 0.4. In small textile fires, the difference between the incapacitation probabilities of sprinklered fires and free-burns was less than the measurement uncertainty. FED results were sensitive to the calculation method due to the different treatment of NOx –gases.Peer reviewe

Report and database on the results of the fire performance experiments

Today, fibre reinforced polymer (FRP) materials are extensively used for building lightweight hull structures of vessels with length up to about 50 metres, whereas in longer vessels their use is limited to secondary structures and components. In the European FIBRESHIP research project, innovative FRP materials are evaluated, new design and production procedures and guidelines are elaborated, and new validated software analysis tools are developed. As a result of the project,   a comprehensive set of methods will be compiled, enabling the building of the complete hull and superstructure of over 50-metre-long ships in FRP materials. The results enhance significantly the use of FRP materials in shipbuilding and strengthen the competitiveness of the European shipbuilding industry on the world market. In Task 2.4 of the FIBRESHIP project, an extensive experimental campaign was performed in two phases to characterize the fire performance of FRP materials and solutions. For the first phase, seven commercially available resins or resin systems were selected for examination of fire performance. Laminates with glass fibre reinforcement and cured resins without reinforcement were produced for cone calorimeter tests and thermogravimetric analyses, respectively. From these seven candidates, two materials were down-selected on the basis of the mechanical performance, manufacturability and impact (including cost, claimed fire retardancy, worker health impact and recyclability). The two material solutions chosen to continue to the second phase were LEO vinylester resin system and SR1125 epoxy resin system. The fire tests of the first phase showed that an intumescent coating on the surface of these laminates is essential for providing adequate fire performance. In the second phase, a more comprehensive evaluation of thermal and fire properties was performed by carrying out more cone calorimeter tests, as well as dynamic mechanical thermal analysis, microscale combustion calorimetry, differential scanning calorimetry and transient plane source tests. Simultaneously, data for pyrolysis modelling, thermomechanical modelling and fire simulation was produced. In cone calorimeter test at the irradiance of 50 kW/m2, the times to ignition of coated LEO and SR1125 were 75 and 52 seconds on the average, respectively. The maximum heat release was 261 kW/m2 for SR1125, but only 69 kW/m2 for LEO indicating good reaction-to-fire performance. The total heat release and the total smoke production were ca. 40 MJ/m2 and 9 m2, respectively, for both systems. Cone calorimeter tests of coated laminate specimens  were run also at the irradiance levels of   25 and 35 kW/m2 and for specimens representing different production batches. The results were not consistent in all cases. In addition, DSC tests revealed changes of the glass transition temperature when the specimens were re-heated, referring to incomplete curing in the manufacturing process. These observations highlight the importance of repeatable and well- controlled manufacturing process. The whole process must be carefully instructed, monitored and reported. The laminates and coatings must be of uniform quality to ensure the fire performance claimed on the basis of fire tests performed. Precise specifications and quality control play a key role in securing the fire safety of materials and products.   Thermogravimetric analyses and micro-scale combustion calorimetry showed that the mass loss of cured resins typically starts slightly above 300 °C both in inert (N2) and oxidative (air) atmosphere. The reactions in these atmospheres differ, the oxidative atmosphere revealing reactions such as char oxidation. At about 300 °C, however, a structure made of these FRP materials starts to produce combustible gases and contribute to fire. Dynamic mechanical thermal analysis showed that the glass transition temperature is ca. 111 °C for LEO, and ca. 95 °C for SR1125. In general, the glass transition temperatures of FRP materials are typically about 100 °C. At this temperature, the material softens and loses its loadbearing capacity. Structures made of FRP materials have a tendency to heat up locally, due to their relatively low thermal conductivity. In the case of a local fire, combustible gas production and heat release are the main concerns in terms of fire safety. If the fire threatens a large structure, like in the case of a compartment fire, the main problem is the softening of the material and the loss of the loadbearing capacity

FIRE SIMULATIONS OF A FISHING RESEARCH VESSEL WITH FRP STRUCTURES

The fire safety effect of using fibre-reinforced polymer (FRP) as the primary construction material in a fishing research vessel was studied by fire simulations. The effect of FRP structures on fire development was assessed by comparing the simulated gas temperatures and potential heat releases with FRP and steel structures. The structural integrity of FRP structures was assessed using simulated temperatures of the structures as indicators of integrity. The effect of protective mineral wool and intumescent coating layers was also quantified. The results showed that despite the protection, the structural integrity of FRP bulkheads could be compromised in fire conditions. Mineral wool was found to be better protection than the intumescent coating: it can either prevent or postpone the pyrolysis of the FRP bulkhead, depending on the fire exposure

Seasonal changes, sleep length and circadian preference among twins with bipolar disorder

BACKGROUND: We aimed at studying the seasonal changes in mood and behaviour, the distribution of hospital admissions by season, and the persistence of the circadian type in twins with bipolar disorder and their healthy co-twins. METHODS: All Finnish like-sex twins born from 1940 to 1969 were screened for a diagnosis of bipolar type I disorder. The diagnosis was assessed with a structured research interview, and the study subjects (n = 67) filled in the Seasonal Pattern Assessment Questionnaire (SPAQ) and the Morningness-Eveningness Questionnaire (MEQ). For studying the persistence of the habitual sleep length and circadian type, we used data derived from the Finnish Twin Cohort Questionnaire (FTCQ). Bipolar twins were compared with their healthy co-twins. RESULTS: Bipolar twins had greater seasonal changes in sleep length (p = 0.01) and mood (p = 0.01), and higher global seasonality scores (p = 0.03) as compared with their co-twins with no mental disorder. Sunny days (p = 0.03) had a greater positive effect on wellbeing in the bipolar than healthy co-twins. CONCLUSIONS: Our results support the view that bipolar disorder is sensitive to the environmental influence in general and to the seasonal effect in specific. Exposure to natural light appears to have a substantial effect on wellbeing in twins with bipolar disorder

Thermo-mechanical analysis of laminated composites exposed to fire

This presentation introduces a numerical model for the thermo-mechanical analysis of laminated composite structures under the fire action. The coupling between the thermal and mechanical behaviour is considered in weak form (temperatures field modify mechanical properties but displacements field do not modify thermal properties). The thermal part of model is based on the approach presented in Henderson et al. (1985). This model takes into account the energy transfer processes of heat conduction, pyrolysis of the polymer matrix, and diffusion of decomposition gases. The mechanical behaviour of the composites is based on the serial/parallel mixing theory (Rastellini et al., 2008) which is modified to take into account the thermal degradation of the mechanical properties. Numerical results obtained with this model are compared with some experimental tests presented in the literature. Application of the developed model to the analysis of fire scenarios in composite ships is evaluated

Computational analysis of resisting marine FRP divisions exposed to fire. Application to the analysis of ship structures.

In this paper a numerical model for thermo-mechanical analysis of laminated composite structures under fire exposure is presented. The analysis is solved using a decoupled approach where temperature modifies the mechanical properties of the constituent materials. The thermal model is based on the research by Henderson et al. [1, 2], which takes into account the energy transfer processes of heat conduction, pyrolysis of the polymer resin and diffusion of decomposed gases. The mechanical model is based on finite element shell elements [3] and the laminated constitutive model is based on damage theory [4, 5, 6] and the serial-parallel rules of mixtures by Rastellini et al. [7], both have been adaptedto introduce the thermal expansion effect and thermal degradation of mechanical properties similar as described by Mouritz [8, 9, 10, 11] and Gibson [12, 13, 14, 15]. The boundary conditions introduced in the thermal model are obtained from a fire dynamics simulation (FDS) [16]. Finally, an application case of a fire collapse analysis of a structure exposed to a fire scenario is presented, the latter specifically demonstrates how the structural integrity of divisions of large-length composite vessels evolves under fire load.This work was funded thanks to H2020 project FIBRESHIP sponsored by the EUROPEAN COM- MISSION under the grant agreement 723360 ”Engineering, production and life-cycle management for complete construction of large-length FIBRE-based SHIPs”. www.fibreship.eu/about And part of the research project NICESHIP sponsored by the Spanish Ministry of Science and Inno- vation under Grant RTI2018-094744-B-C21.Peer ReviewedObjectius de Desenvolupament Sostenible::13 - Acció per al ClimaObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version