scholarly journals An Innovative Steel Damper with a Flexural and Shear–Flexural Mechanism to Enhance the CBF System Behavior: An Experimental and Numerical Study

2021 ◽  
Vol 11 (23) ◽  
pp. 11454
Author(s):  
Ali Ghamari ◽  
Behroz Almasi ◽  
Chang-hyuk Kim ◽  
Seong-Hoon Jeong ◽  
Kee-Jeung Hong
Keyword(s):  
Numerical Study ◽  
High Accuracy ◽  
Hysteresis Curve ◽  
Test Results ◽  
System Behavior ◽  
Steel Damper ◽  
The Cross ◽  
Strength And Stiffness ◽  
The Web ◽  
Ultimate Displacement

An innovative passive energy damper is introduced and studied experimentally and numerically. This damper is designed as the main plate for energy absorption which is surrounded by an octagon cover. In addition to simplicity in construction, it can be easily replaced after a severe earthquake. Experimental test results, as well as finite element results, indicated that, by connecting the cross-flexural plate to the main plate, the mechanism of the plate was changed from flexural to shear. However, the cross_flexural plate always acts as a flexural mechanism. Changing the shear mechanism to a flexural mechanism, on the other hand, increased the stiffness and strength, while it reduced the ultimate displacement. Comparing the hysteresis curve of specimens revealed that models without cross_flexural plates had less strength and energy_dissipating capability than other models. Adding the flexural plate to the damper without connecting to the main plate improved the behavior of the damper, mainly by improving the ultimate displacement. Connecting the cross plate to the web plate enhanced the ultimate strength and stiffness by 84% and 3.9, respectively, but it reduced the ductility by 2.25. Furthermore, relationships were proposed to predict the behavior of the dampers with high accuracy.

The Numerical Simulation for Steel Plate Reinforced Concrete Coupling Beams Based on Abaqus

2014 ◽  
Vol 1065-1069 ◽  
pp. 1354-1357
Author(s):  
Dong Chen ◽  
Cheng Fan ◽  
Li Song
Keyword(s):  
Reinforced Concrete ◽  
Steel Plate ◽  
Numerical Study ◽  
Damage Model ◽  
Hysteresis Curve ◽  
Test Results ◽  
Coupling Beams ◽  
Tsinghua University ◽  
Model And Simulation ◽  
Actual Test

Based on the concrete plasticity damage model provide by the Abaqus, the subroutine PQ-fiber provided by the TsingHua University was used to build the model and simulation for the steel plate reinforced concrete (SPRC) coupling beams. The embedded column and steel plate stress nephogram, concrete stress nephogram and hysteresis curve which was get after the simulation and which were compared with the actual test, the simulation results can fit the actual test results better, which provide some userful reference for the numerical study for the steel plate reinforced concrete coupling beams.

Local buckling capacity of C-shaped cold-formed steel sections with punched webs

1984 ◽  
Vol 11 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert Loov
Keyword(s):  
Local Buckling ◽  
Effective Width ◽  
Test Results ◽  
Average Yield ◽  
Steel Sections ◽  
Load Tests ◽  
Cold Formed Steel ◽  
Stub Column ◽  
Best Fit ◽  
The Web

Load tests were carried out on 36 stub column samples of cold-formed steel studs having 38.1 mm wide × 44.5 mm long holes punched through their webs, steel thicknesses of 1.21–2.01 mm, and overall section depths of 63–204 mm. Based on these tests a best-fit equation for the effective width of the unstiffened portion of the web beside the holes has been developed. Suggested design equations have been proposed. The test results support the present equation for the average yield stress [Formula: see text] in Canadian Standards Association Standard S136-1974 but the present code equations for unstiffened plates are unduly conservative when applied to the design of the web adjacent to openings of the size considered.

Numerical Simulation of Gas Flow and Heat Transfer in Cross-Wavy Primary Surface Channel for Microtubine Recuperators

2005 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang ◽  
L. Q. Luo ◽  
Z. P. Feng
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Gas Turbine ◽  
Numerical Study ◽  
High Reliability ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
The Cross

Three-dimensional numerical simulation was conducted to investigate the flow field and heat transfer performance of the Cross-Wavy Primary Surface (CWPS) recuperators for microturbines. Using high-effective compact recuperators to achieve high thermal efficiency is one of the key techniques in the development of microturbine in recent years. Recuperators need to have minimum volume and weight, high reliability and durability. Most important of all, they need to have high thermal-effectiveness and low pressure-losses so that the gas turbine system can achieve high thermal performances. These requirements have attracted some research efforts in designing and implementing low-cost and compact recuperators for gas turbine engines recently. One of the promising techniques to achieve this goal is the so-called primary surface channels with small hydraulic dimensions. In this paper, we conducted a three-dimensional numerical study of flow and heat transfer for the Cross-Wavy Primary Surface (CWPS) channels with two different geometries. In the CWPS configurations the secondary flow is created by means of curved and interrupted surfaces, which may disturb the thermal boundary layers and thus improve the thermal performances of the channels. To facilitate comparison, we chose the identical hydraulic diameters for the above four CWPS channels. Since our experiments on real recuperators showed that the Reynolds number ranges from 150 to 500 under the operating conditions, we implemented all the simulations under laminar flow situations. By analyzing the correlations of Nusselt numbers and friction factors vs. Reynolds numbers of the four CWPS channels, we found that the CWPS channels have superior and comprehensive thermal performance with high compactness, i.e., high heat transfer area to volume ratio, indicating excellent commercialized application in the compact recuperators.

Component Based Method for Usability Testing of a Website

2013 ◽  
Vol 765-767 ◽  
pp. 1507-1511
Author(s):  
Saeeda Sharmeen Rahman ◽  
Jing Nong Weng
Keyword(s):  
Software Engineering ◽  
Modular Forms ◽  
Web Site ◽  
Usability Testing ◽  
Test Results ◽  
Testing Method ◽  
Component Based Software Engineering ◽  
User Friendly ◽  
University Web Site ◽  
The Web

This paper presents the Component-Based Software Engineering (CBSE) approach for usability testing of a web-site based on ISO 9241-11 usability guidance to achieve specified goals with effectiveness, efficiency and satisfaction. Usability testing is a technique used to evaluate a product by testing it on users. A particular type of website i.e. university web site was chosen and segmented in different components in modular forms according to the purpose of that component. Then component wise tasks as per ISO 9241-11 usability guidance were prepared to carry out the usability testing for evaluating the test web-site. After analyzing the results of component based usability testing, a proto-type version of the test web-site was designed in a limited form including all the feedback of test results. Finally, the proto-type web-site was re-evaluated for establishing the effectiveness of component based web usability method with the same tasks. The proposed component based usability testing method is expected to improve the design/content issues of web-site resulting the web-site much more user friendly, effective and less time and cost consuming.

scholarly journals Application of linear polarized light for the discrimination of frozen and liquid droplets in ice nucleation experiments

2012 ◽  
Vol 5 (4) ◽  
pp. 5753-5785 ◽  
Author(s):  
T. Clauss ◽  
A. Kiselev ◽  
S. Hartmann ◽  
S. Augustin ◽  
S. Pfeifer ◽  
...  
Keyword(s):  
Liquid Droplet ◽  
Polarized Light ◽  
Pulse Height ◽  
Forward Direction ◽  
Diffusion Chamber ◽  
Spherical Particles ◽  
Test Results ◽  
Ice Particles ◽  
Immersion Freezing ◽  
The Cross

Abstract. We report on the development and test results of the new optical particle counter TOPS-Ice (Thermostabilized Optical Particle Spectrometer for the detection of Ice particles). The instrument uses measurements of the depolarized component of light scattered by single particles into the near-forward direction (42.5° ± 12.7°) to distinguish between spherical and non-spherical particles. This approach allows the differentiation between liquid water droplets (spherical) and ice particles (non-spherical) having similar volume equivalent sizes and therefore can be used to determine the fraction of frozen droplets in a typical immersion freezing experiment. We show that the numerical simulation of the light scattering on non-spherical particles (ellipsoids in random orientation) with account for the actual scattering geometry used in the instrument supports the validity of the approach, even though the cross polarized component of the light scattered by spherical droplets is not vanishing in this scattering angle. For the separation of the ice particle mode from the liquid droplet mode, we use the width of the pulse detected in the depolarization channel instead of the pulse height. Exploiting the intrinsic relationship between pulse height and pulse width for Gaussian pulses allows us to calculate the fraction of frozen droplets even if the liquid droplet mode dominates the particle ensemble. We present test results obtained with TOPS-Ice in the immersion freezing experiments at the laminar diffusion chamber LACIS (Leipzig Aerosol Cloud Interaction Simulator) and demonstrate the excellent agreement with the data obtained in the same experiment with a different optical instrument. Finally, the advantages of using the cross-polarized light measurements for the differentiation of liquid and frozen droplets in the realistic immersion freezing experiments are discussed.

scholarly journals Experiment and Design Method on Cold-Formed Thin-Walled Steel Lipped Channel Columns with Slotted Web Holes Under Axial Compression

2017 ◽  
Vol 11 (1) ◽  
pp. 244-257 ◽  
Author(s):  
Xingyou Yao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ultimate Strength ◽  
Test Results ◽  
Distortional Buckling ◽  
Steel Columns ◽  
Cold Formed Steel ◽  
Thin Walled ◽  
Shell Finite Element ◽  
The Web

Background: Cold-formed steel structural sections used in the walls of residential buildings and agricultural facilities are commonly C-shaped sections with web holes. These holes located in the web of sections can alter the elastic stiffness and the ultimate strength of a structural member. The objective of this paper is to study the buckling mode and load-carrying capacity of cold-formed thin-walled steel column with slotted web holes. Methods: Compression tests were conducted on 26 intermediate length columns with and without holes. The tested compressive members included four different kinds of holes. For each specimen, a shell finite element Eigen-buckling analysis and nonlinear analysis were also conducted. The influence of the slotted web hole on local and distortional buckling response had also been studied. The comparison on ultimate strength between test results and calculated results using Chinese cold-formed steel specification GB50018-2002, North American cold-formed steel specification AISI S100-2016, and nonlinear Finite Element method was made. Result: Test results showed that the distortional buckling occurred for intermediate columns with slotted holes and the ultimate strength of columns with holes was less than that of columns without holes. The ultimate strength of columns decreased with the increase in transverse width of hole in the cross-section of member. The Finite element analysis results showed that the web holes could influence on the elastic buckling stress of columns. The shell finite element could be used to model the buckling modes and analysis the ultimate strength of members with slotted web holes. The calculated ultimate strength shows that results predicted with AISI S100-2016 and analyzed using finite element method are close to test results. The calculated results using Chinese code are higher than the test results because Chinese code has no provision to calculate the ultimate strength of members with slotted web holes. Conclusion: The calculated method for cold-formed thin-walled steel columns with slotted web holes are proposed based on effective width method in Chinese code. The results calculated using the proposed method show good agreement with test results and can be used in engineering design for some specific cold-formed steel columns with slotted web holes studied in this paper.

scholarly journals Experimental and Numerical Study on Ultimate Shear Load Carrying Capacity of Corroded RC Beams

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhanzhan Tang ◽  
Zhixiang He ◽  
Zheng Chen ◽  
Lingkun Chen ◽  
Hanyang Xue ◽  
...  
Keyword(s):  
Shear Strength ◽  
Bearing Capacity ◽  
Cross Section ◽  
Loss Rate ◽  
Numerical Study ◽  
Rc Beams ◽  
Load Carrying ◽  
Shear Bearing Capacity ◽  
The Cross ◽  
The Impact

For an RC beam, the strength of steel rebar, the bonding strength between the concrete and reinforcement, and the bite action between the aggregates will deteriorate significantly due to corrosion. In the present study, 10 RC beams were designed to study the impact of corrosion on the shear bearing capacity. The mechanism of corrosion for stirrups and longitudinal bars and their effects were analyzed. Based on the existing experimental data, the correlation between the stirrup corrosion factor and the cross section loss rate was obtained. An effective prediction formula on the shear bearing capacity of the corroded RC beams was proposed and validated by the experimental results. Moreover, a numerical analysis approach based on the FE technique was proposed for the prediction of the shear strength. The results show that corrosion of the reinforcements could reduce the shear strength of the RC beams. The corrosion of stirrups can be numerically simulated by the reduction of the cross section. The formulae in the literature are conservative and the predictions are very dispersed, while the predictions by the proposed formula agree very well with the experiment results.

scholarly journals Numerical Study on Heat and Mass Transfer of the Cross-flow Liquid Desiccant Regenerator

2017 ◽  
Vol 205 ◽  
pp. 2647-2654 ◽  
Author(s):  
Yang Li ◽  
Zhibo Fu ◽  
Xiaohu Yang ◽  
Lianying Zhang ◽  
Qunli Zhang ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Numerical Study ◽  
Cross Flow ◽  
Liquid Desiccant ◽  
The Cross

Developing Intelligent Semantic Web Services

2011 ◽  
pp. 422-438
Author(s):  
Sam Lee
Keyword(s):  
Web Services ◽  
Semantic Web ◽  
Code Generation ◽  
Intelligent Agent ◽  
Semantic Web Services ◽  
Behavior Model ◽  
System Behavior ◽  
Heterogeneous Information ◽  
High Degree ◽  
The Web

This chapter introduces an approach to the development of intelligent Semantic Web services, which are envisioned as system cells that actively discover, learn, and communicate knowledge on the Web. The development of these systems often involves not only standardized Web technology, but also the integration of heterogeneous information. The approach in this chapter adopts the Semantic Web services specifications that are given by the DARPA agent markup language (DAML) program, utilizes a system behavior model to represent an intelligent agent, and proposes a high degree of automatic synthesis using code generation and program templates. The author reviews the various techniques that are available to aid the development process, and provides an example to illustrate the stages of software synthesis in the development of such systems.

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