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Online since: August 2022
Authors: Mohsen A. Hassan, Ahmed H. Hassanin, Ignatius Ebo-Quansah, Tadaharu Adachi
Complex constitutive model which captures material behaviour such as plasticity, fracture mechanism through stress-strain data obtained at both quasi-static and large strain rates were implemented to adequately relate simulation to the physical problem.
In this work, data for the Johnson-Cook plasticity and failure models which express the equivalent flow stress as function strain rate, strain hardening and temperature for both target steel and projectile were taken from references [1,20].
There was a reduction in initial velocity of projectile to a residual velocity value of 460 m/s.
Variation in velocity reduction for both S2-W1-S2 and S2-W2-S2 models (refer to Fig. 5 for notation) were very small.
In this work, data for the Johnson-Cook plasticity and failure models which express the equivalent flow stress as function strain rate, strain hardening and temperature for both target steel and projectile were taken from references [1,20].
There was a reduction in initial velocity of projectile to a residual velocity value of 460 m/s.
Variation in velocity reduction for both S2-W1-S2 and S2-W2-S2 models (refer to Fig. 5 for notation) were very small.
Numerical Study on Heat Transfer of Turbulent Flow in a Channel with Composite Arrangement Obstacles
Online since: August 2013
Authors: Mohsin Mohd Sies, Mazlan Abdul Wahid, Mohammad Parsazadeh, Farshid Fathinia, Amirhossein Heshmati
Data Reduction.
This model was presented better agreement in measured data at the current geometry [8].
However this priority on heat transfer enhancement was changed to the trapezoidal obstacles with increasing height in flow direction (case 4) at upper wall due to reduction on low heat transfer areas which were produced at the corners of the obstacles.
This model was presented better agreement in measured data at the current geometry [8].
However this priority on heat transfer enhancement was changed to the trapezoidal obstacles with increasing height in flow direction (case 4) at upper wall due to reduction on low heat transfer areas which were produced at the corners of the obstacles.
Online since: December 2014
Authors: Jing Li
These terminals uninterruptedly collect data and information to related objects, and promptly upload to the network layer.
Network layer includes WEB, application servers, and data servers.
Next, the vehicle exhaust in north China is to be monitored and tracked, meanwhile the data should be collected and coped timely.
Comprehensive monitoring system that is the combination of fixed data collection points and movable data collection points can be used during the IOT establishment of air pollution monitoring.
By deepening the data layer and evaluating comprehensively, we can build a more unified center for data monitoring and a service platform for data sharing of atmospheric environment in north China.
Network layer includes WEB, application servers, and data servers.
Next, the vehicle exhaust in north China is to be monitored and tracked, meanwhile the data should be collected and coped timely.
Comprehensive monitoring system that is the combination of fixed data collection points and movable data collection points can be used during the IOT establishment of air pollution monitoring.
By deepening the data layer and evaluating comprehensively, we can build a more unified center for data monitoring and a service platform for data sharing of atmospheric environment in north China.
Online since: November 2012
Authors: Rong Zhang
But the random and irregular load time history curve gained at wind farm is irregular, in which many data are ineffective for the fatigue analysis, these ineffective data can be deleted when making statistics treatment [12].
The method to modify S-N curve is the reference stress amplitude of finite life region multiplied by one reduction coefficient SPu: (3) In the Eq.3[5], when reduction coefficient SPu =2/3, its relative survival rate Pu>97.7%( i.e. the mean reduces 2 times standard deviation) If considering the casting defects like chill, crack etc, it has the casting defect coefficient St (4) In Eq.4[5], t is the thickness influence coefficient.
The method to modify S-N curve is the reference stress amplitude of finite life region multiplied by one reduction coefficient SPu: (3) In the Eq.3[5], when reduction coefficient SPu =2/3, its relative survival rate Pu>97.7%( i.e. the mean reduces 2 times standard deviation) If considering the casting defects like chill, crack etc, it has the casting defect coefficient St (4) In Eq.4[5], t is the thickness influence coefficient.
Online since: June 2014
Authors: Eng Juraj Králik
According to EN1992-1-2, EN1993-1-2 and EN 1994-1-2 the assessment of structural behavior in a fire design situation shall be based on one of the following permitted design procedures:
Ü recognized design situations on the base of the tabulated data,
Ü simple calculation models for specific type of structural members,
Ü advanced calculation models able to deal with any kind of the structural model.
Fig. 1 Concept of Response Surface Method This method is based on the assumption that it is possible to define the dependency between the variable input and the output data through the approximation functions in the following form: (6) where co is the index of the constant member; ci are the indices of the linear member and cij the indices of the quadratic member, which are given for predetermined schemes for the optimal distribution of the variables or for using regression analysis after calculating the response [11].
Fig. 4 The stress-strain relationships The reduction factors for material properties depends on temperature load curve.
Histogram Mean Standard deviation Min. value Max. value Material Young’s modulus Ek mvar Lognormal 1,100 0,066 0,000 1,299 Stress yield fyk fvar Lognormal 1,100 0,066 0,000 1,299 Reduction factor ky kvar Lognormal 1,000 0,050 0,000 1,149 Load Permanent Gk gvar Normal 1,000 0,030 0,916 1,084 Variable Qk qvar Gama T.I 0,600 0,215 0,000 1,378 Fire-temperature Tk tvar Gama T.I 0,822 0,246 0,000 1,684 Model Model-uncertaint. xE evar Lognormal 1,000 0,050 0,000 1,149 Resistance-uncert. xR rvar Lognormal 1,000 0,050 0,000 1,149 In the probabilistic analysis there is the value of effect of actions E defined in accordance with the JCSS code [7] (EN 1991-1-1. 2002) follow and (8) where are the variable functions defined as the histograms.
Fig. 1 Concept of Response Surface Method This method is based on the assumption that it is possible to define the dependency between the variable input and the output data through the approximation functions in the following form: (6) where co is the index of the constant member; ci are the indices of the linear member and cij the indices of the quadratic member, which are given for predetermined schemes for the optimal distribution of the variables or for using regression analysis after calculating the response [11].
Fig. 4 The stress-strain relationships The reduction factors for material properties depends on temperature load curve.
Histogram Mean Standard deviation Min. value Max. value Material Young’s modulus Ek mvar Lognormal 1,100 0,066 0,000 1,299 Stress yield fyk fvar Lognormal 1,100 0,066 0,000 1,299 Reduction factor ky kvar Lognormal 1,000 0,050 0,000 1,149 Load Permanent Gk gvar Normal 1,000 0,030 0,916 1,084 Variable Qk qvar Gama T.I 0,600 0,215 0,000 1,378 Fire-temperature Tk tvar Gama T.I 0,822 0,246 0,000 1,684 Model Model-uncertaint. xE evar Lognormal 1,000 0,050 0,000 1,149 Resistance-uncert. xR rvar Lognormal 1,000 0,050 0,000 1,149 In the probabilistic analysis there is the value of effect of actions E defined in accordance with the JCSS code [7] (EN 1991-1-1. 2002) follow and (8) where are the variable functions defined as the histograms.
Online since: May 2014
Authors: Xiao Yuan Wu, Qing Hua Pang, Yuer Chen
The existing productions are mostly limited on static analysis of indexes’ cross section data and lack consideration on dynamic development.
Based on the connotation and character of the compound system optimization of a basin initial water rights allocation [5,7,14], as well as the available research results of comprehensive evaluation index system of an initial water rights allocation scheme, we establish the index system of a basin initial water rights allocation scheme on the basis of the investigation and extensive collection of the basin data, and the basin research and interview work, and the suggestion by the river basin administrative agencies and experts in the field of the water environment and water resources, with methods of literature reading, frequency analysis, attribute reduction algorithm, and results reference.
Zhang, “The index system construction of province initial water rights allocation system based on the algorithm of attribute reduction”, Inter.
Based on the connotation and character of the compound system optimization of a basin initial water rights allocation [5,7,14], as well as the available research results of comprehensive evaluation index system of an initial water rights allocation scheme, we establish the index system of a basin initial water rights allocation scheme on the basis of the investigation and extensive collection of the basin data, and the basin research and interview work, and the suggestion by the river basin administrative agencies and experts in the field of the water environment and water resources, with methods of literature reading, frequency analysis, attribute reduction algorithm, and results reference.
Zhang, “The index system construction of province initial water rights allocation system based on the algorithm of attribute reduction”, Inter.
Online since: September 2013
Authors: Jun Guo He, Jian Liu, Jian Hao Zhou, Min Zhou, Qi Chao Hu
Fair and Gemmell [1] confirmed the importance of breakage process in the modeling of flocculation dynamics in the early computer simulation; Boadway and Lu [5, 6] found that both particle coagulation and flocs breakage needed to be taken into consideration in mathematical modeling to match the test data; Pandya and Spielman [7] made a detailed study of breakage phenomenon with the use of fluid visualization technology, and further revealed the mechanism of flocs breakage in sheared fluid and defined a detailed model to describe the breakage dynamics; Costas [8] simulated particle aggregation and breakage.
Whether based on numerical simulation or experimental observation, within the range of the shear strength examined in this study, reduction of shear strength produced more large flocs.
The size of the peak concentration did not increase rapidly with the gradual reduction of shear strength.
Spielman, Floc breakage in agitated suspensions: theory and data processing strategy, J.
Whether based on numerical simulation or experimental observation, within the range of the shear strength examined in this study, reduction of shear strength produced more large flocs.
The size of the peak concentration did not increase rapidly with the gradual reduction of shear strength.
Spielman, Floc breakage in agitated suspensions: theory and data processing strategy, J.
Online since: January 2013
Authors: Agus Haryono, Sri Budi Harmami, Dewi Sondari
This is because of their unique magnetic and electric properties as well as numerous applications in the fields of data storage, ferrofluids, nano-adsorbents, Magnetic Resonance Imaging, biomedicine, biosensor, bio-separation, etc. [2-11].
The particle size of 2 nm, which data was compared to Transmission Electron Microscopy Image (TEM), the aggregation state of the particles can be determined.
Cr(VI) reduction by Pseudomonas aeruginosa immobilized in a polyvinyl alcohol/sodium alginate matrix containing multi-walled carbon nanotubes.
Tang; Degradation of lead contaminated lignocellulosic waste by Phanerochaete chysosporium at th reduction of lead toxicity.
The particle size of 2 nm, which data was compared to Transmission Electron Microscopy Image (TEM), the aggregation state of the particles can be determined.
Cr(VI) reduction by Pseudomonas aeruginosa immobilized in a polyvinyl alcohol/sodium alginate matrix containing multi-walled carbon nanotubes.
Tang; Degradation of lead contaminated lignocellulosic waste by Phanerochaete chysosporium at th reduction of lead toxicity.
Online since: February 2008
Authors: Jie Zhou, Jurek Duczczyk, Gang Liu, K. Huang
Table 1 Dimensions and initial temperatures of the workpiece and extrusion tooling
Billet length [mm] 812 Reduction ratio 19.6
Billet diameter [mm] 202 Billet temperature [°C] 450
Container insider diameter [mm] 203 Tooling temperature [°C] 400
Container outside diameter [mm] 360
(a) (b)
Fig. 1 (a) Cross section of the rectangular hollow profile with the shaded area selected for FE
simulation and (b) porthole die used to produce the profile.
The flow stress-strain data of the AA7020 alloy determined from hot compression tests at temperatures from 250 to 575 °C and strain rates from 0.01 to 100 s -1 and then corrected for deformational heating [4] were used as the input data of the workpiece material.
At this stage, the reduction ratio is quite low, only 2.25.
The flow stress-strain data of the AA7020 alloy determined from hot compression tests at temperatures from 250 to 575 °C and strain rates from 0.01 to 100 s -1 and then corrected for deformational heating [4] were used as the input data of the workpiece material.
At this stage, the reduction ratio is quite low, only 2.25.