EXPERIMENTAL STUDY OF LOCAL SOLID WOOD POST-FIRE BEHAVIOUR

UKaRsT ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 207
Author(s):  
Ni Nyoman Kencanawati ◽  
B Anshari ◽  
J Fajrin ◽  
Hariyadi Hariyadi ◽  
A Beriman

When wood structures are exposed to high temperatures, they will decompose to provide a char layer and pyrolysis zone, an insulating material that inhibits further degradation. This experimental study aims to determine the char thickness and pyrolysis of solid wood exposed to fire for 30, 45, and 60 minutes. The post-fire shear strength has also been evaluated. The solid woods were locally from Nusa Tenggara Island, namely Jati Putih, Bajur, and Rajumas. According to the Indonesian National Standard of the heating curve for structures, the temperature growth was SNI-1741: 2008. Obtained The char layer's highest average thickness was within 60 minutes of combustion with the highest temperature of 1055oC. The char layer for Jati Putih, Bajur, and Rajumas are 2.12 mm, 7.89 mm, and 6.53 mm. Meanwhile, the pyrolysis layers are 8.78 mm, 9.13 mm, and 14.82 mm, respectively, for Jati Putih, Bajur, and Rajumas. Besides, the post-fire shear strength of all wood species shows an increase in shear strength in the core. Wood can still sustain the load during a fire because there is a char layer preventing the core section from immediately exposed to the fire.    

2021 ◽  
Vol 116 ◽  
pp. 78-85
Author(s):  
Aneta Gumowska ◽  
Grzegorz Kowaluk

The quality of the wood bonding depending on the method of applying the selected thermoplastic biopolymers. The aim of the research was to determine the effect of the method of applying the biopolymer on the surface of bonding solid wood elements on the quality of the obtained adhesive connection. The results of conducted mechanical research show that the highest average value of shear strength was observed for birch lamellas bonded with PLA, both with the first and second method of application. In case of estimating the quality of the bonding of wooden elements, better results were achieved for PLA and the second method of application the "green" adhesive.


2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Andreas Vogel ◽  
Adam J. Durant ◽  
Massimo Cassiani ◽  
Rory J. Clarkson ◽  
Michal Slaby ◽  
...  

Volcanic ash (VA) clouds in flight corridors present a significant threat to aircraft operations as VA particles can cause damage to gas turbine engine components that lead to a reduction of engine performance and compromise flight safety. In the last decade, research has mainly focused on processes such as erosion of compressor blades and static components caused by impinging ash particles as well as clogging and/or corrosion effects of soft or molten ash particles on hot section turbine airfoils and components. However, there is a lack of information on how the fan separates ingested VA particles from the core stream flow into the bypass flow and therefore influences the mass concentration inside the engine core section, which is most vulnerable and critical for safety. In this numerical simulation study, we investigated the VA particle–fan interactions and resulting reductions in particle mass concentrations entering the engine core section as a function of particle size, fan rotation rate, and for two different flight altitudes. For this, we used a high-bypass gas-turbine engine design, with representative intake, fan, spinner, and splitter geometries for numerical computational fluid dynamics (CFD) simulations including a Lagrangian particle-tracking algorithm. Our results reveal that particle–fan interactions redirect particles from the core stream flow into the bypass stream tube, which leads to a significant particle mass concentration reduction inside the engine core section. The results also show that the particle–fan interactions increase with increasing fan rotation rates and VA particle size. Depending on ingested VA size distributions, the particle mass inside the engine core flow can be up to 30% reduced compared to the incoming particle mass flow. The presented results enable future calculations of effective core flow exposure or dosages based on simulated or observed atmospheric VA particle size distribution, which is required to quantify engine failure mechanisms after exposure to VA. As an example, we applied our methodology to a recent aircraft encounter during the Mt. Kelud 2014 eruption. Based on ambient VA concentrations simulated with an atmospheric particle dispersion model (FLEXPART), we calculated the effective particle mass concentration inside the core stream flow along the actual flight track and compared it with the whole engine exposure.


2011 ◽  
Vol 374-377 ◽  
pp. 2520-2524 ◽  
Author(s):  
Gang Shi ◽  
Jian Xing Zhang ◽  
Yuan Qing Wang ◽  
Hui Juan Huang ◽  
Zheng Hong Zhang

In this paper, the experimental study on the self-tapping screw’s pullout resistance in the wood structure was conducted. Domestic ordinary screws were used together with imported or domestic wood to fabricate 6 screw connection specimens in wooden walls. Then monotonic loading tests were conducted and it can be concluded that, the common round screw connection strength mainly depends on the failure mode, the lack of cooperation effect significantly influences the strength of screw connections, and the dispersion of screw connection stiffness is high. So, to obtain formulae for the self-tapping screw connection strength and stiffness by further experimental study will be very necessary.


2015 ◽  
Vol 33 (3) ◽  
pp. 247-266 ◽  
Author(s):  
Pauline Tranchard ◽  
Fabienne Samyn ◽  
Sophie Duquesne ◽  
Matthieu Thomas ◽  
Bruno Estèbe ◽  
...  

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