Fire Resistance Test of Concrete Composite Box Steel Girder Floor System

2014 ◽  
Vol 665 ◽  
pp. 188-191
Author(s):  
Jun Li Lv ◽  
Kao Zhong Zhao
Keyword(s):  
Temperature Rise ◽  
Vertical Displacement ◽  
System Structure ◽  
Bottom Plate ◽  
Large Temperature ◽  
Steel Girder ◽  
Whole Process ◽  
Plane Plate ◽  
The Cross ◽  
Floor System

The concrete composite box steel girder floor system is a new box-section ribbed hollow floor system. It is an integral structure integrated the girder and plates by the “composite box”, one of the precast composite members and the rear casting ribbed girder and has been widely used in the buildings with large span and heavy load. The article researches its whole process under the effects of the fire and the service load. In the whole process of test, the temperature field, vertical displacement, displacement within the plane, plate edge corner and other parameters of the different sections have been measured. The results show that: the concrete at the bottom plate of the composite box bottom plate quickly bursts off during the fire; later, the bottom plate of the composite box is out of operation; the floor structure becomes cross girder structure; as the temperature rises, after the floor system structure becomes the cross girder structure, the torque of the four-side ribbed girder of the floor system increases and the diagonal cracks occur on the four-side ribbed girder; as the temperature rises, there is large temperature gradient on the floor system ribbed girder along with the cross section height; the flexural deformation occurs to the floor system while the expanding deflection occurs in the plane; the maximum vertical displacement is achieved after the temperature rise stops; along with the drop of the temperature, the flexural deformation gradually recovers; after the tested temperature rise has been conducted for 292 minutes, the floor system still has good fire resistant capacity

Heat Transfer and Crystallization Modeling during Compression Molding of Thermoplastic Composite Parts

2015 ◽  
Vol 651-653 ◽  
pp. 1507-1512 ◽  
Author(s):  
Jalal Faraj ◽  
Baptiste Pignon ◽  
Jean Luc Bailleul ◽  
Nicolas Boyard ◽  
Didier Delaunay ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Physical Properties ◽  
Volume Fraction ◽  
Thermoplastic Composite ◽  
Large Temperature ◽  
Process Conditions ◽  
Thermoplastic Resin ◽  
Whole Process ◽  
Low Viscosity ◽  
Thermo Physical Properties

We present in this paper, the coupling of heat transfer to the crystallization of composite in a closed mold. The composite is based on thermoplastic resin (low viscosity PA 66) with glass fiber (50% volume fraction). In order to realize this coupling, an accurate characterizationof thermo physical properties in process conditions, especially in the molten and solid state is needed. In addition, theidentification of the parameters of crystallization kinetics is required. Therefore, we present the methods that were used to study the thermo physical properties as the thermal conductivity, heat capacity and the specific volume. Moreover, the kinetic of crystallization was estimated over a large temperature range by using Flash DSC and classical DSC. In order to validate the measurements, the whole process was modeled by finite elements. The model includes the resolution of the strong coupling between the heat transfer and crystallization. Finally, the experimental and numerical results were compared.

Trampling the Archaeological Record: An Experimental Study

1991 ◽  
Vol 56 (3) ◽  
pp. 483-503 ◽  
Author(s):  
Axel E. Nielsen
Keyword(s):  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Characteristic Size ◽  
Archaeological Record ◽  
Whole Process ◽  
Horizontal Size ◽  
Size Sorting ◽  
Materials Used ◽  
Empirical Generalizations ◽  
Behavioral Inference

This paper reports on several experiments carried out to explore the transformations of the archaeological record affected by trampling. These transformations include changes in artifact distributions and formal alterations that should be taken into account when carrying out studies of activity areas. The experiments were made on dry, hard-packed surfaces and in the same sediments after a rain. The materials used were bones, obsidian flakes, sherds, and fragments of brick and wood. The analysis focuses on vertical displacement, horizontal displacement, and damage (breakage, microflaking, and abrasion), paying special attention to the response of the trodden substrate and its implications for the whole process. The interaction of trampling with other formation processes (e.g., maintenance) also is considered. The main patterns observed in the trampled materials are vertical and horizontal size sorting, and characteristic size distributions in sherds. These empirical generalizations are then integrated in a model that can help to identify trampled contexts and assess their potential for behavioral inference.

scholarly journals Experimental Studies on a Solar Air Heater Having V-Corrugated Absorber Plate with Obstacles Bent Vertically

2014 ◽  
Vol 493 ◽  
pp. 86-92 ◽  
Author(s):  
Ekadewi A. Handoyo ◽  
Djatmiko Ichsani ◽  
Prabowo ◽  
S. Sutardi
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flat Plate ◽  
Air Temperature ◽  
Temperature Rise ◽  
Experimental Studies ◽  
Bottom Plate ◽  
Solar Air Heater ◽  
Absorber Plate ◽  
Air Heater

A solar air heater (SAH) is a simple heater using solar radiation that is useful for drying or space heating. Unfortunately, heat transfer from the absorber plate to the air inside the solar air heater is low. Some researchers reported that obstacles are able to improve the heat transfer in a flat plate solar air collector and others found that a v-corrugated absorber plate gives better heat transfer than a flat plate. Yet, no work of combining these two findings is found.This paper describes the result of experimental study on a SAH with v-corrugated absorber plate and obstacles bent vertically started from 80oto 0owith interval 10oon its bottom plate. Experiments were conducted indoor at five different Reynolds numbers (1447 Re 7237) and three different radiation intensities (430, 573, and 716 W/m2).It is found that the obstacles improve SAH performance. Both the air temperature rise and efficiency increase with inserting obstacles bent at any angle vertically. Unfortunately, the air pressure drop is increasing, too. Obstacles bent vertically at smaller angle (means more straight) give higher air temperature rise and efficiency. However, the optimum angle is found 30o. The air temperature rise and efficiency will be 5.3% lower when the obstacles bent 30oinstead of 0o, but the pressure drop will be 17.2% lower.

Evaluation of a Data Center Recirculation Non-Uniformity Metric Using Computational Fluid Dynamics

2011 ◽  
Author(s):  
Dustin W. Demetriou ◽  
H. Ezzat Khalifa
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Simple Model ◽  
Temperature Rise ◽  
Data Center ◽  
Large Temperature ◽  
Inlet Temperature ◽  
Temperature Pattern ◽  
Cfd Analysis ◽  
Tile Flow

The work presented in this paper is an extension of the companion work by the authors on a simplified thermodynamic model for data center optimization, in which a recirculation non-uniformity metric, θ, was introduced and used in a parametric analysis to highlight the deleterious effect of recirculation non-uniformity at the inlet of racks on the data center cooling infrastructure power consumption. In this work, several studies are done using a commercial computational fluid dynamics (CFD) package to verify many of the assumptions necessary in the development of the simplified model and to understand the degree of recirculation non-uniformity present in typical data center configurations. A number of CFD simulations are used to quantify the ability of the simple model at predicting θ. The results show that the simple model provides a fairly accurate estimate of θ, with a standard deviation in the prediction error of ∼10–15%. The CFD analysis are also to understand the effect of row length and server temperature rise (ΔTs) temperature non-uniformity. The simulations show that reasonable values of θ range from 2–6 for open aisle data centers depending on operating strategy and data center layout. As a means to understand the effect of buoyancy, a data center Archimedes number (Ar), the ratio of buoyancy to inertia forces, is introduced as a function of tile flow rate and server temperature rise. For servers with modest temperature rise (∼ 10.0°C), Ar is ∼0.1; however, for racks with large temperature rise (∼20°C), Ar > 1.0, meaning buoyancy needs to be considered important. Through CFD analysis the significant effect buoyancy has on the inlet rack temperature patterns is highlighted. The Capture Index (ψ), the ratio of cold air ingested by the racks to the required rack flow, is used to investigate its relationship to the ratio of server flow to tile flow (Y), as the inlet rack temperature patterns are changed by increased Ar. The results show that although the rack inlet temperature patterns are extremely different, ψ does not change significantly as a function of Ar. Lastly, the effect of buoyancy on the assumption of linearity of the temperature field is considered for a range of Ar. The results show the emergence of a stratified temperature pattern at the inlet of the racks as Ar increases and buoyancy becomes more important. It is concluded that under these conditions, a δT change in tile temperature does not produce a δT change in temperature everywhere in the field.

Cloud-Computing-Based Biomedical Information Sharing Business Model

2014 ◽  
Vol 556-562 ◽  
pp. 6199-6202
Author(s):  
Hui Jie Ding ◽  
Chun Jiang Yu ◽  
Shu Huang
Keyword(s):  
Cloud Computing ◽  
Information Sharing ◽  
Medical Information ◽  
System Structure ◽  
Medical Information System ◽  
Distributed Programming ◽  
Medical Computing ◽  
Computing Platform ◽  
Whole Process ◽  
Virtual Platform

The presence of large amounts of Data Island in medical information system seriously hindered the whole process coordination and integration of the health service. To solve above problems, this paper, on the basis of the analysis of characteristics of medical information resources, put forward medical information sharing system based on cloud computing, discussed the medical computing platform and key technology of the system structure and in the technical implementation, on the basis of Hadoop platform and virtual platform Tashi, demonstrates the feasibility of the system by using graphs to cloud computing distributed programming.

scholarly journals Strain Monitoring of Combustible Gas Implosion Test Based on Fiber Bragg Grating

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Lei Gao ◽  
Qinghua Zhang ◽  
Erbing Li ◽  
Yangyang Sun ◽  
Zhenglin Zhang ◽  
...  
Keyword(s):  
Strain Amplitude ◽  
Electromagnetic Interference ◽  
Effective Strain ◽  
Electrical Measurement ◽  
Bottom Plate ◽  
Test Results ◽  
Whole Process ◽  
Strain Monitoring ◽  
Combustible Gas ◽  
Fbg Sensors

Strain measurement is an important component in model tests of combustible internal explosions. Strain gauges are used to measure strain in traditional electrical measurement methods and have some limitations, such as susceptibility to electromagnetic interference, short life, and inability to distribute. Fiber Bragg gratings (FBGs) are developing into useful sensing tools that can respond to changes in stress, strain, and temperature by changing wavelengths. FBGs have excellent sensing performance, such as long life, antielectromagnetic interference, easy networking, and good reusability. In this paper, FBG sensors are applied to strain monitoring in ethylene flammable implosion experiments. In the ethylene flammable implosion tests, an FBG was placed on the inner surface of the bottom plate of the rectangular steel test device near the detonation vent by the sticking method. The reliability and repeatability of the strain change of the FBG affected by detonation overpressure and combustion were tested at this point. Four explosion tests were carried out. The test results showed that FBG sensors could obtain stable and reliable strain data in all four tests. The strain variation reflects the development of overpressure and combustion in the whole process from ignition. For the strain amplitude formed by overpressure, the minimum was 1.449 με (the third test), and the maximum was 48.181 με (the fourth test).For the strain amplitude step change formed by the deflagration flame front passing the measurement points, the minimum was 1.673 με (the second test), and the maximum was 19.724 με (the fourth test).The strain amplitude produced by the deflagration temperature effect in the four tests ranged from 72.803 με (the first test) to 143.381 με (the fourth test).The results show that FBG sensors can provide reliable and effective strain monitoring data for the experimental study of flammable implosions.

Study on Stresses Distribution Pattern of Wide Box Steel Girder of Arch Bridge

2013 ◽  
Vol 275-277 ◽  
pp. 1158-1162
Author(s):  
Qing Tian Su ◽  
Fei Ren ◽  
Yuan Wei Liu
Keyword(s):  
Distribution Pattern ◽  
Transverse Direction ◽  
Bottom Plate ◽  
Transverse Stress ◽  
Combined Stress ◽  
Steel Girder ◽  
Box Girder ◽  
Arch Bridge ◽  
Shell Elements ◽  
Uniformity Coefficient

Shell elements were used to simulate the wide box girder of arch bridge. Different load cases on the arch bridge were calculated and the stress distribution pattern of the wide girder was obtained. The results show that the stresses of the top plate and the bottom plate are non-uniformity along transverse direction at same section, the maximum non-uniformity coefficient of the top plate and the bottom plate are 1.89 and 1.73 respectively. To arch bridge with large ratio of width to length, the transverse stress of girder should not be neglected and the combined stress should be used to determine the structure safety.

Seismic Design of a Double Deck Floating Roof Type Used for Liquid Storage Tanks

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Mohammad Ali Goudarzi
Keyword(s):  
Seismic Design ◽  
Design Procedure ◽  
Hydrodynamic Pressure ◽  
Nonlinear Effects ◽  
Vertical Displacement ◽  
Bottom Plate ◽  
Liquid Storage ◽  
Geometric Nonlinear ◽  
General Displacement ◽  
Seismic Stress

Sloshing response of a cylindrical liquid storage tank with the double deck type floating roof (DDFR) subjected to seismic excitation is considered in this paper. The aim of the paper is to clarify the significant parameters that should be considered in the seismic design of a DDFR and proposing a practical seismic design procedure for evaluating the dynamic stresses inside a DDFR. A numerical method including fluid–structure interaction and the geometry details of a DDFR tank are established. The geometric nonlinear effects on the seismic behavior of the DDFR as well as the accuracy of common analytical solution suggested in the literature are examined by the numerical model. The numerical results show that the geometric nonlinear effects can considerably reduce the seismic stress in DDFR, but have no significant effect on the liquid hydrodynamic pressure exerted on the DDFR and the roof's vertical displacement. It is also revealed that not only the general displacement of DDFR but also the local effects of liquid hydrodynamic pressure on the bottom plate should be considered for seismic design of a DDFR. Finally, a design procedure for the evaluation of dynamic stress in the DDFR due to the seismic loads is proposed and discussed.

Analysis and Improvement of a 3 Axis Accelerometer

2012 ◽  
Vol 503 ◽  
pp. 163-168
Author(s):  
Shi Tao Wang ◽  
Yu Bin Jia ◽  
Bin Zhen Zhang ◽  
Xue Song Liu ◽  
Qin Wen Huang ◽  
...  
Keyword(s):  
Cross Talk ◽  
Proof Mass ◽  
Vertical Displacement ◽  
Sensing Element ◽  
Mems Accelerometer ◽  
Symmetrical Structure ◽  
Mechanical Coupling ◽  
Asymmetrical Structure ◽  
Simulation Results ◽  
The Cross

In this paper, an integrated 3-axis MEMS accelerometer was analyzed. Because of asymmetrical structure, z-axis sensing element, which was imbedded in the proof mass of lateral accelerometers, had large mechanical coupling. Simulation result showed that the cross talk in z-axis was as high as 64.3%. To solve the problem, a fully symmetrical structure with vertical springs was adopted in z-axis sensing element. The movement of z-axis was linear vertical displacement instead of torsional displacement. Simulation results showed there was no obvious cross talk in z-axis sensing element.

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