Numerical model to predict the effect of wood density in wood–steel–wood connections with and without passive protection under fire

2020 ◽  
Vol 38 (2) ◽  
pp. 122-135 ◽  
Author(s):  
Elza MM Fonseca ◽  
Lino Silva ◽  
Pedro AS Leite
Keyword(s):  
Numerical Model ◽  
Wood Density ◽  
Room Temperature ◽  
Steel Plate ◽  
Fire Exposure ◽  
Layer Depth ◽  
Passive Protection ◽  
Char Layer ◽  
Charring Rate ◽  
Wood Char

The main objective of this work is to present a numerical model to predict the effect of wood density in unprotected wood connections with an internal steel plate (wood–steel–wood), when comparing with the same connections using passive protection with gypsum plasterboard, submitted to fire conditions. Wood–steel–wood connections are made of four wood members, two on each side, with an internal steel plate that connects the pieces using steel dowel fasteners. First, analytical methodologies according to Eurocode 5 part 1-1 were used to design the connections at room temperature. After that, to predict the fire exposure and the connection ability, a numerical model was performed which permits to compare the fire resistance in wood–steel–wood connections without and with passive protection following the Eurocode 5 part 1-2. Results of the temperature and the wood char layer depth were compared using three different wood densities. The evolution of the charring rate was calculated in different locations of the connections and compared with the analytical value proposed by the Eurocode 5 part 1-2.

The Numerical Analysis of Temperature Field During Moveable Induction Heating of Steel Plate

2012 ◽  
Vol 28 (02) ◽  
pp. 73-81
Author(s):  
Xue-biao Zhang ◽  
Yu-long Yang ◽  
Yu-jun Liu
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Numerical Model ◽  
Induction Heating ◽  
Temperature Difference ◽  
Steel Plate ◽  
Heating Process ◽  
Quasi Steady State ◽  
Initial State ◽  
Plate Temperature

In shipyards, hull curved plate formation is an important stage with respect to productivity and accuracy control of curved plates. Because the power and its distribution of induction heat source are easier to control and reproduce, induction heating is expected to be applied in the line heating process. This paper studies the moveable induction heating process of steel plate and develops a numerical model of electromagneticthermal coupling analysis and the numerical results consistent with the experimental results. The numerical model is used to analyze the temperature changing rules and the influences on plate temperature field of heating speed of moveable induction heating of steel plate, and the following conclusions are drawn. First, the process of moveable induction heating of steel plate can be divided into three phases of initial state, quasi-steady state, and end state. The temperature difference between the top and bottom surfaces of the steel plate at the initial state is the biggest; it remains unchanged at the quasi-steady state and it is the smallest at the end state. Second, obvious end effect occurs when the edges of the steel plate are heated by the inductor, which causes a decrease in temperature difference between the top and bottom surfaces of the steel plate that is unfavorable for formation of pillow shape plates. Third, with the increase of heating speed, the temperature difference between the top and bottom surfaces of the steel plate increases gradually.

Behavior of the Spruce and Birch Wood from the Fire Safety Point of View

2013 ◽  
Vol 842 ◽  
pp. 725-728 ◽  
Author(s):  
Petr Kučera ◽  
Antonín Lokaj ◽  
Vladimír Vlček
Keyword(s):  
Heat Flux ◽  
Carbon Monoxide ◽  
Flux Density ◽  
Fire Safety ◽  
Maximum Concentration ◽  
Heat Flux Density ◽  
Point Of View ◽  
Birch Wood ◽  
Char Layer ◽  
Charring Rate

In the presented paper is comprehensively assessed the behavior of spruce and birch wood during fire. Samples were loaded by heat flux of 20, 35 and 50 kW/m2in apparatus according to ISO 5657. The duration of the test was up to 30 min. The behavior of the samples was evaluated on the basis of charring rate and concentrations of carbon monoxide in smoke. Charring rate was rising with increasing heat flux density and decreasing linearly with increasing density of the samples. The maximum concentration of CO in the smoke for spruce and birch wood was observed just before the end of the test, during the phase of char layer burning.

The charring depth and charring rate of glued laminated timber after a standard fire exposure test

2009 ◽  
Vol 44 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Te-Hsin Yang ◽  
Song-Yung Wang ◽  
Ming-Jer Tsai ◽  
Ching-Yuan Lin
Keyword(s):  
Fire Exposure ◽  
Exposure Test ◽  
Standard Fire ◽  
Glued Laminated Timber ◽  
Charring Rate

Friction Stir Welding of Carbon Steel for Application in Used Fuel Containers

2014 ◽  
Vol 783-786 ◽  
pp. 1753-1758 ◽  
Author(s):  
Murray Mahoney ◽  
Sam Sanderson ◽  
Peter Maak ◽  
Russell Steel ◽  
Jon Babb ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Room Temperature ◽  
Steel Plate ◽  
Ultrasonic Inspection ◽  
Weld Zone ◽  
Friction Stir Weld ◽  
Weld Repair ◽  
Friction Stir ◽  
Flat Steel ◽  
Two Phases

Friction Stir Welding (FSW) is being investigated as a method to fabricate a partial penetration closure weld of the steel vessel of a copper-coated used fuel container. The hemi-head is made of A516 Grade 70 steel and the cylinder body is made of A106 Grade C steel. In this initial feasibility study, the objective is to use FSW to demonstrate the merits of FSW using flat steel plate in concert with a closure weld joint designed specifically for a cylindrical container. To complete this objective, there are two initial feasibility demonstrations. First, demonstrate the capability of FSW to create defect free welds in a corner joint design with specific dimensions (10 mm deep weld nugget). Subsequently, verify the weld quality by ultrasonic inspection and metallography. Further, characterize weld zone properties by establishing mechanical properties and hardness at room temperature, and impact toughness at-5°C. Second, demonstrate the ability to use FSW to repair defects that might occur in the initial friction stir weld. Weld repair was accomplished by intentionally creating tunnel defects by FSW, performing metallography and ultrasonic inspection to characterize the morphology of the defects, performing a second friction stir weld repair over the defects, and verifying the subsequent weld integrity by repeating the metallography and ultrasonic inspections. Results on these initial two phases of this program are presented herein.

Thermal Hydraulic Analysis Towards a Robust Design of Leak Collection Tray for Pool Type Sodium Cooled Fast Reactors

2010 ◽  
Author(s):  
Anil Kumar Sharma ◽  
K. Velusamy ◽  
N. Kasinathan ◽  
P. Chellapandi ◽  
S. C. Chetal ◽  
...  
Keyword(s):  
Room Temperature ◽  
Liquid Sodium ◽  
Passive Protection ◽  
Sodium Transfer ◽  
Oxygen Starvation ◽  
Parametric Studies ◽  
Protection Devices ◽  
Transient Thermal ◽  
Thermal Hydraulic Analysis ◽  
Pool Type

To protect the sodium cooled FBR plant against the hazardous effects of sodium leak into the ambient, one of the passive protection devices used is the Leak Collection Trays (LCT) below the secondary sodium carrying pipelines in the Steam Generator Building (SGB). The design of LCT is based on immediate channeling of burning liquid sodium on the funnel shaped ‘sloping cover tray’ to the bottom ‘sodium hold-up vessel’ in which self-extinction of the fire occurs due to oxygen starvation. In the secondary heat transfer circuits of FBRs, leakage of liquid sodium from the pipelines is postulated as one of the design basis accidents with probability of occurrence at 10−2 per reactor year. LCT collect the leaked sodium in a hold up vessel, suppress the sodium fire due to oxygen starvation and guide the sodium to an inerted ‘sodium transfer tank’ located at the bottom most elevation of the SGB. The procedure of draining the leaked sodium into the transfer tank has been envisaged as a defense in depth measure against the handling of un-burnt sodium and to guard against larger leak rates than that can be handled by the LCT effectively. Towards this, a network of carbon steel pipelines are laid out connecting all the LCT and the transfer tank through headers in strategic locations, each having a fusible plug. The fusible plug separates the air environment in LCT and argon environment in sodium transfer tank. Woods metal is the preliminary choice for the fusible plug. It is an alloy of 50% Bi, 25% Pb, 12.5% Sn and 12.5% Cd with a melting point of 72°C. The transfer tank is filled with argon at ∼ 0.03 bars-g pressure. Both the header and the tank are at room temperature during normal conditions. Leaked sodium by virtue of its high temperature has to heat up the fusible plug to melt the same and drain into the transfer tank. Transient thermal hydraulic investigations have been carried out to predict the fusing characteristics of woods metal plug. The numerical results have been validated against analytical solutions for idealized conditions. Detailed parametric studies have been carried out with plug thickness as a parameter. It is established that effective melting of the plug and trouble free draining of the leaked sodium is possible for a 3 mm thick fusible plug.

scholarly journals Influence of heating elements dynamics on energy savings

2018 ◽  
Vol 9 (2) ◽  
pp. 169-173
Author(s):  
O. Šikula ◽  
O. Ladjedel ◽  
P. Charvát ◽  
L. Adjlout ◽  
S. A. Reffas
Keyword(s):  
Numerical Model ◽  
Thermal Comfort ◽  
Computer Simulations ◽  
Room Temperature ◽  
Energy Savings ◽  
Thermal Inertia ◽  
Living Room ◽  
New Type ◽  
Dynamic Heating

Dynamic heating computer simulations of one model typical living room heated alternatively by two types of heating bodies are presented in this paper. This contribution describes a numerical model of two heating elements (plate radiator and a new type of convector) showing different thermal inertia by using the TRNSYS software. The results show energy savings approximately of 10% for the new tested convector, where the thermal comfort is better in terms of reaching the required room temperature.

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