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Online since: October 2011
Authors: Ze Li, Li Xiang Zhang
The concrete damaged plasticity model assumes that the reduction of the elastic modulus is given in terms of a scalar degradation variable, , as (4) where is the damaged Young’s modulus of the concrete material.
The rectangular coordinate system center of the model is located at the right crossing points of dam axis and datum plane, with the vertical y-axis pointing in the upward direction and the horizontal x-axis pointing in the downstream direction, the horizontal x-axis pointing in the right bank direction of the river.
Due to the tensile stress concentration in this area, the tensile damage variables (DAMAGET) have reached 1.0 after 4.0 seconds earthquake action, and the strength reduction and stiffness degradation are occurred.
The elastic-plasticity concrete damage model can reflect the mechanical behavior under the dynamic loads action, and can simulate the strength reduction and stiffness degradation of concrete material.
Online since: December 2010
Authors: Shi Qin He, Peng Fei Li, Feng Shang
This software is capable of establishing a mesh for reinforced concrete structures and steel-concrete composite structures, picking up the stress-strain data of each element, and analyzing the damage and cracked state of the concrete [8].
Fig. 3 details of the composite beams and FE model of composite beam Fig. 4a gives the load-mid span deflection curves obtained by FEM compared with the experiment data.
The computed strain history of the steel bar in the mid-span and that of steel girder as well as the slip between girder and slab are compared with the experiment data in Fig. 4b, Fig. 5a-5b, respectively.
(a) (b) Fig. 6: (a) Details of continuous beam (b) FE model of continuous beam Fig. 7a shows the comparison of computed nonlinear load-deflection relation with the experimental data.
The proposed analytical approach matches the experiment data well.
Online since: September 2013
Authors: Bin Shen, Zheng Guo Liu, Jun Qing Liu, Zi Qing Wang
Construction of remote diagnosis system based on Browser/Server mode The B/S model includes a presentation layer, function layer and data layer three.
The presentation layer is the user interface part of the application, charged with the user and application of dialogue function; function layer is equivalent to the application of the body, it is the specific business process logic coding program; data layer database management system, used to define, pipe and processing database and application responsible for the management of database connection, data read and write.
USER Data query Virtual training virtual assembly Virtual repair Remote repair System update Remote support system manufactory research academy leader Fig1.
Network diagnosis and repair decision will design, manufacture, installation, use, maintenance and management of organic through data link, achieve equipment safety, reliable operation of the accurate judgments of equipment fault reason, nature, position, the possible consequences of behavior.
[5] Wang W,Peng D M,Wang H G,Sharif H,Chen H H.Energy-constrained distortion reduction optimization for wavelet.based coded image transmission in wireless sensor networks[J].IEEE Transactiom on Multimedia,2008,10(6);1169-1180
Online since: September 2017
Authors: Dong Xiang Jiang, Wen Guang Yang, Te Han
Following the procedure of data-driven approach, the degradation feature can be excavated from a large amount of historical data, and further be applied for state assessment [3,4].
(1) Based on monitored data of rolling bearing, N samples can be collected at a certain degradation state.
Case Study To demonstrate the effectiveness of the proposed method, the degradation test rig of rolling bearing is built on which the experimental data is collected.
The applicability of this method is verified by the experimental data.
Multifeatures Fusion and Nonlinear Dimension Reduction for Intelligent Bearing Condition Monitoring.
Online since: April 2013
Authors: Raj Kumar Sahu, Karali Patra
In general at very small region, the elastomeric stress-strain curve is often fairly linear, which quantify initial Young’s modulus (which follows Hooke’s law).Tensile test on carbon nanotube-reinforced silicone elastomers shows dramatic enhancement of initial E-modulus as a function of loads up to a strain value of 10% accompanied by reduction in ultimate properties [4].
Both force and stretch were measured and the data are plotted in Fig.3.
When & are assumed, then Eq.2 can be written as Therefore the least square error can be written as (5) Material constants for Mooney-Rivlin model are determined from the experimental force-strain data using least square optimization method.
Model predicted force-strain data are fitted to the experimental force-strain values and material constants =0.05848, = 0.206*10-5, K1=1.591 and K2=4.514 were found at a strain value of 1600%.
Elastic modulus at different stretch values (upto 1600%) was calculated by applying tangent method on the experimental data and model predicted data and shown in Table1.
Online since: September 2013
Authors: Jian Ming Zhu, Ze Xiang Wu, Chong Yang, Qi Zhao
In this paper, we consider the three-dimensional stress state of rock, choose the SMP failure criterion which is consider the influence of intermediate principal stress, establish the post-peak strain softening constitutive relations, obtaine the stress - strain curve curve of post-peak, compared with the data of diorite porphyry triaxial compression test from xiaoguanzhuang iron mining area, the results have a good consistency.
Post-peak constitutive model When rock into the peak strain softening stage, the structure is a unique structure, mainly show discontinuity on the mechanical and the conditional conversion, the rock mass strength is greatly reduce at this time, the extent of reduction is determined by the rock mass properties(internal friction Angle and cohesion ) and joints fracture surface characteristics.
When the rock reach the elastic brittle turning point , it into the formula (6) (7) (8) to get a unified expression of the residual stress and the confining pressure based the SMP criterion: (9) Analysis and discussion the experimental data The test equipment is the type MTS815.03 rock mechanics testing machine from IWHR Rock Mechanics Laboratory, the main technical indicators: Axial compression is 4500kN, Confining pressure is 140Mpa, Stiffness is 1800kN/mm.
Fig.5 Triaxial compression test the stress-strain curve Fig.6 Relationship curves of post-peak ε and φ Confining pressure and the residual stress from the test data regression analysis can get residual stress expression
Analyze the data of diorite porphyry triaxial compression test from xiaoguanzhuang iron mining area, calculate the elastic brittle turning point, and establish a more precise curve fitting formula(12) ; combined with the curve of the peak strain and the internal friction angle, draw out the SMP strength criterion in different confining pressures of stress-strain curve (Figure 7) ,compared with the experimental data, the result can be better to describe the mechanical behavior of the residual stress after the peak.
Online since: March 2012
Authors: Jian Qiang Lu, Dao Zong Sun, Xiang Jun Zou
Thus, it can further promote the energy saving and emission reduction. 1.
Serial clock, RAM reading and writing data can communicate by a byte or up to 31 bytes character set.
With the low power consumption, DS1302 can maintain the data and clock information when power is less than 1mW.
Firstly, when the microcontroller is going to work, the system is startup and reads setting data which is stored in the EEPROM in the moment.
These data includes switch status of every socket, the startup of automatic control and time of automatic control.
Online since: February 2013
Authors: Jian Guo Cui, Lei Zhang, Zhao Cheng Zhang
At present, heavy metals processing method are: chemical precipitation method, oxidation-reduction method, the adsorption method, a membrane separation method, biological method, etc.
Compare the result of removal Cu(II) and Cr(Ⅵ) in different oxidation pH as Fig.2 According to the data of Fig.2, formula as the following: Cu(II): y= -1.26x2+24.4x-35.1 (3) Cr(Ⅵ): y= -1.37x2+15.7x+5.75 (4) The equations indicate: With the increase of pH in the oxidation phase, the removal rate of Cu (II) and Cr (Ⅵ) increase.
Compare the result of removal Cu(II) and Cr(Ⅵ) in different oxidation time as Fig.3 According to the data of Fig.3, formula as the following: Cu(II): y= -0.085x2+5.33x-0.46 (5) Cr(Ⅵ): y= -0.76x2+4.73x-7.98 (6) Fig.3 Influence of oxidation time Fig.4 Influence of pH in the flocculation phase At the beginning of reaction,Fe(Ⅲ) which has high concentration can remove Cu(II) Cu(II) quickly.
Compare the result of removal Cu(II) and Cr(Ⅵ) in different flocculation pH as Fig.4 According to the data of Fig.4, formula as the following Cu(II): y= -4.36x2+71.72x-213.71 (7) Cr(Ⅵ): y= -3.35x2+56.72x-172.31 (8) The equations indicate: With the increase of pH in the flocculation phase, the removal rate of Cu (II) and Cr (Ⅵ) increase.The removal rate of Cu (II) and Cr (Ⅵ) decreased when PH>9.
Compare the result of removal Cu(II) and Cr(Ⅵ) in different flocculation time as Fig.5 According to the data of Fig.5, formula as the following Cu(II): y= 12.47ln(x)+31.37 (9) Cr(Ⅵ): y= 38.41ln(x)-75.23 (10) Fig.5 Influence of flocculation time The equations indicate: With the increase of the flocculation time, the removal rate of Cu (II) and Cr (Ⅵ) increase.
Online since: June 2011
Authors: Kuei Shu Hsu, Feng Tsai Weng, Long Jyi Yeh, Tsung Han Li
Experiment Result The servo motor movement will need time to implement an end to once again receive an external signal to drive the implementation, this will become a waste of time, even if the new incoming image data not drive, which is the main reason for this study, Thread, in the implementation of Thread performance is not fully using the servo motor when the action is often caused by waiting for video delay, but this time target tracking system but will not perform to wait, but also according to the image track into the biggest problem.
Using computer simulation trajectory for humanoid tracking system to do continuous tracking of the movement, the figure Experiment data for the computer simulation of the trajectory motion path, Tracking data image for the humanoid vision system to track the path.
Image in the human vision system and image processing required for the important but time consuming, therefore the cut for the image is divided into parts: acquisition, noise reduction, target orientation, image matching, image tracking.
On the contrary, such as using threads (Thread) performance improvement to the implementation of human stereo visual system, programs, performance improvement due to the thread execution time required for shorter image acquisition completed action done to remove noise, which can speed up the time perform positioning, comparison and tracking, and servo motor positioning in the receiving information the first time, you can speed up the process of driving down the middle movement, movement speed rising to come in the next image data can be completed before the action, greatly reduce the visual servo control error, enhancing system performance and stability time.
The LQG problem for multirate sampled-data systems.
Online since: December 2012
Authors: Liang Kai Fan, Li Yuan, Hua Wang, Shi Bin Geng
Greater or less than the rated air volume, will make the dehumidifier dehumidifying capacity reduction.
Figure 1 Nozzle structure diagram 1.2 Brief diagram of test equipment sampler hygrothermograph artificial climate chamber manometer variable frequency fan Power-measuring device Figure 2 Brief diagram of test equipment 1.3 Data acquisition The temperature, humidity sensor measuring equipment at various points of the temperature and humidity of the air, and send a signal to a computer.
Data acquisition software developed by VB6.0.It uses manual measuring and recording start time, system dehumidifying capacity.
Table 1 Orthogonal experiment factor level table Column number Test number Volume A Temperature B Humidity C — — SMER 1 2 3 4 5 6 7 -- 1 1 1 1 1 1 1 1 -- 2 1 1 1 2 2 2 2 -- 3 1 2 2 1 1 2 2 -- 4 1 2 2 2 2 1 1 -- 5 2 1 2 1 2 1 2 -- 6 2 1 2 2 1 2 1 -- 7 2 2 1 1 2 2 1 -- 8 2 2 1 2 1 1 2 -- Table 2 Test conditions and test results data table Serial number 1 2 3 4 Before and after the nozzle static pressure difference Volume Inlet air dry-bulb temperature Inlet air wet-bulb temperature Inlet air relative humidity SMER Pa m3/h ℃ ℃ % kg/kWh 1 68.6 2000 20 11.8 35% 1.33 2 68.6 2000 20 15.2 60% 1.71 3 68.6 2000 27 17 35% 1.51 4 68.6 2000 27 21.3 60% 1.8 5 154.4 3000 20 11.8 35% 1.28 6 154.4 3000 20 15.2 60% 1.93 7 154.4 3000 27 17 35% 1.25 8 154.4 3000 27 21.3 60% 1.88 2.2 Test result and analysis Multiple factors in the comparative trials, to investigate factors on index of effect size, you can see it under every level data average dispersion, in general, the
[4] Bai Xingui, Data Analysis and Optimization Design of Tests, Tsinghua University Publications,Beijing,1986
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