Archive

15 March 2006, Volume 27 Issue 3 Previous Issue    Next Issue
---
OriginalPaper


For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

OriginalPaper

Select

Optimal provisioning and dynamic pricing analysis of a class of monopolized network systems Yue, Xiao-Ning (1); Jing, Yuan-Wei (1); Yin, Feng-Jie (1) 2006, 27 (3):  237-239.  DOI: - Abstract ( 207 )   HTML   PDF (1093KB) ( 454 )   Formulates the dynamic pricing management strategy of network systems the way: The Cobb-Douglas demand function is introduced in the optimization theory and economic boundary theory to analyze the optimal provisioning and dynamic pricing of non-monopoly network systems. Thus an optimal management strategy is given to maximize the profit of the network systems. Discusses how the monopoly affect the demand elasticity of their users. This management strategy is adaptable to not only the demand of the increasing number of network users but the diversity of network applications. Simulation results reveal its reasonability and effectiveness. References | Related Articles | Metrics

Select

Design of a robust active queue management algorithm based on fuzzy variable structure control Yin, Feng-Jie (1); Jing, Yuan-Wei (1); Yue, Xiao-Ning (1) 2006, 27 (3):  240-243.  DOI: - Abstract ( 205 )   HTML   PDF (168KB) ( 552 )   An active queue management (AQM) algorithm is presented on the basis of fuzzy logic control (FLC). Combining the sliding mode controller (SMC) with a proportional plus integral (PI) control, the algorithm has both the advantages of SMC and PI controller. Thus, it is highly robust not only available to the uncertainties of network modeling uncertainties, time varying of network parameters and network jittering due to non-TCP sessions, but to minimize the steady-state error through PI control. Simulation results demonstrate that good transient/steady state responses to queue can be obtained by applying the proposed algorithm and that the algorithm is highly robust to disturbance under various networks conditions and outperforms significantly both the traditional PI control and traditional variable structure control. References | Related Articles | Metrics

Select

Sub-optimal control of T-S fuzzy descriptor system Zhou, Lin-Na (1); Zhang, Qing-Ling (1); Liu, Guo-Yi (1) 2006, 27 (3):  244-247.  DOI: - Abstract ( 275 )   HTML   PDF (854KB) ( 736 )   Based on T-S fuzzy system model, a class of nonlinear descriptor systems is modeled to give a sufficient condition on which the fuzzy state feedback controller exists to ensure the fuzzy descriptor system a quadratic stability with the upper bond of the quadratic performance index of the controlled system determined. Then, a method to minimize the upper bond of the quadratic performance function is obtained in terms of linear matrix inequalities, as well as the method to design the controller that provides the system with quadratic stability. A numerical example was given to illustrate the feasibility and validity of the design method proposed. References | Related Articles | Metrics

Select

Inverse optimal control for a four-dimensional chaotic system Xie, Ying-Hui (1); Zhang, Hua-Guang (1) 2006, 27 (3):  248-251.  DOI: - Abstract ( 295 )   HTML   PDF (921KB) ( 678 )   A linear state feedback controller is designed for controlling a four-dimensional chaotic system by the inverse optimal controlling approach. Based on the Lyapunov stability theory, the designed controller is proved enable to globally stabilize asymptotically the controlled system to return to its zero balance point and minimize the proposed cost functional. Two sets of data from numerical simulation show the effectiveness, readiness and robustness of the controller. The chaotic trajectory of the controlled 4-D system can be controlled to return to its zero balance point under different initial conditions. References | Related Articles | Metrics

Select

Analysis of exponential stability for a class of nonlinear stochastic interval systems Wang, Yi-Zhong (1); Zhang, Hua-Guang (1) 2006, 27 (3):  252-255.  DOI: - Abstract ( 221 )   HTML   PDF (2146KB) ( 724 )   For a class of nonlinear stochastic time varying delaying interval systems, its exponential stability is discussed. In the system the nonlinear terms are unknown and there are uncertain parameters contained in the antecedent of each term, which vary in a definite interval. By Young's inequality, the properties of the eigenvalues and norms, the Lyapunov Second Method and Razumikhin-type theorem of stochastic differential equations, the internal stability of the systems is analyzed, thus giving the sufficient condition of the exponential stability of the systems. A design scheme is proposed to ensure the system's exponential stability. References | Related Articles | Metrics

Select

Research on correlation between rolling-force and monitoring AGC systems Tan, Shu-Bin (1); Zhong, Yun-Feng (2); Xu, Xin-He (1) 2006, 27 (3):  256-259.  DOI: - Abstract ( 260 )   HTML   PDF (846KB) ( 712 )   The accuracy of final strip gauge on hot strip mill depends on what gauge control means are adopted at each stand. It is possible to introduce different kinds of automatic gauge control (AGC) systems in the mill to work simultaneously. If so, different AGC systems may impact on each other with mutual disturbance while adjusting the roll gap in position. Rolling-force AGC and monitoring AGC are independent of each other if some AGC system parameters were preset suitably. In order to implement a decoupling control, the parameters and structure of the AGC system on a hot rolling mill were modified. As a result, it was proved theoretically that the rolling-force AGC system and monitoring AGC system could be independent of each other by computer simulation and mathematic models, namely, decoupling control of these two AGC systems was realized in the true sense. References | Related Articles | Metrics

Select

Recognition of manmade target and natural object through fractal Zeng, Peng-Xin (1); Yao, Jian-Shi (2); Zhu, Lin-Lin (1); Xu, Xin-He (1) 2006, 27 (3):  260-263.  DOI: - Abstract ( 308 )   HTML   PDF (362KB) ( 669 )   Based on object's fractal dimension, an approach was proposed to differ manmade target from natural objects. According to the innate difference between manmade targets and natural objects, fractal dimension was taken as a very important parameter to estimate the surface roughness, and the surface roughness of the target was calculated by the algorithm proposed by Peleg et al. The method is fast, simple and effective. Experimental result showed that the number of fractal dimensions of manmade targets is lower than that of natural objects. It is feasible to differ manmade targets from natural objects by the fractal dimension calculation. References | Related Articles | Metrics

Select

Research on test system of competitive tele-operated robot Hao, Li-Na (1); Li, Qing-Yun (2); Wang, Dan (2); Xu, Xin-He (2) 2006, 27 (3):  264-267.  DOI: - Abstract ( 250 )   HTML   PDF (247KB) ( 867 )   Describes the characteristics of competitive and cooperative Multi-Operator Multi-Robot (MOMR) systems for the task of tele-operation of MOMR system on Internet. A new ideal test platform was proposed first for competitive tele-operated MOMR system, i.e., a robot soccer based on C/S module to tele-operate on Internet, of which the key technologies are stated in detail, such as the system architecture and software programming of control system at server terminal and tele-operating user terminal. In the whole system the technologies of Windows operation system, VC++, and Winsock network programming have been introduced in some competitions that rely on the specified regulations were given as examples. The results showed that this system could simulate the whole process of man-controlled soccer competitions and meet the relevant demands of stability and reliability. References | Related Articles | Metrics

Select

Image reconstruction algorithm for complex temperature field Sun, Xiao-Ping (1); Tian, Feng (2); Shao, Fu-Qun (1); Xie, Zhi (1) 2006, 27 (3):  268-271.  DOI: - Abstract ( 256 )   HTML   PDF (255KB) ( 776 )   The reconstruction algorithm plays a key role in reconstructing acoustically the flame temperature field in coal-burning boiler hearth. A new algorithm is proposed to realize the image reconstruction of complex temperature field, i.e., adding a prior information matrix to the reconstruction of temperature field to realize the image reconstruction of complex temperature field with less measured data of time for sound transmission. Experiments based on this algorithm were done on the experimental setup we developed for the reconstruction of actual flash flame temperature field. The results showed that the new algorithm is available to realize the field image reconstruction of complex temperature field. References | Related Articles | Metrics

Select

QoS-based packet scheduling algorithm in wireless networks Zhao, Yue (1); Luo, Xiao-Hua (1); Yang, Peng (1); Wang, Guang-Xing (1) 2006, 27 (3):  272-275.  DOI: - Abstract ( 208 )   HTML   PDF (189KB) ( 923 )   Proposes a packet scheduling algorithm adaptable to wireless networks, i.e., the Dynamic Probabilistic Priority (DPP). Introducing the dynamic priority dispatching strategy, the DPP algorithm can meet different requirements of QoS. In addition, if errors occur in wireless networks, the algorithm can dynamically assign bandwidths to make full use of them. It will not only improve the throughput of system, but also ensure algorithm s fairness. Both theoretical analysis and simulating test indicate that DPP algorithm works better in wireless networks. References | Related Articles | Metrics

Select

Bayesian network model for fault diagnosis of hydropower equipment Zhang, Xiao-Dan (1); Zhao, Hai (1); Xie, Yuan-Mang (2); Yin, Zhen-Yu (1) 2006, 27 (3):  276-279.  DOI: - Abstract ( 274 )   HTML   PDF (800KB) ( 521 )   The fault diagnosis based on Bayesian network is studied by analyzing the uncertainty and limitation found in the existing fault diagnosis commonly used for hydropower equipment. A Bayesian network architecture available to such fault diagnosis is proposed with relevant uncertainty reasoning and clique tree propagation algorithm described. In the diagnosis method proposed many factors are taken into account, such as multiple-fault, fuzzy fault symptoms and the mutual dependency of different operation to be done with the equipment of a hydropower plant. With the fault diagnosis for a speed governor in Fengman Hydropower Station as example, a simulation test was carried out and verified the effectiveness and accuracy of the decision via the fault diagnosis under conditions of uncertain information. References | Related Articles | Metrics

Select

Application of support vector machine in pattern classification of surface EMG Cui, Jian-Guo (1); Wang, Xu (1); Li, Zhong-Hai (2); Zhang, Da-Qian (2) 2006, 27 (3):  280-283.  DOI: - Abstract ( 259 )   HTML   PDF (171KB) ( 942 )   A new pattern recognition method of surface electromyography (sEMG) is proposed, based on wavelet transform and support vector machine (SVM). The original four-channel sEMG signals from four corresponding muscles are analyzed with wavelet transform, then the singular values of wavelet decomposition coefficients are extracted to be the signal characteristics to construct eigenvector. A new multi-class SVM classifier is designed according to the 'one by one' classification strategy and binary tree. Experiment results show that the eight forearm movement patterns can be well recognized after training by the SVM with average recognition rate up to 98.75%, and that the SVM can sort out sEMG eight movement patterns more accurately than conventional BP neural, Elman neural and RBF neural networks, with high robustness also provided. The method proposed can be directly applied to the pattern recognition of other nonstationary bioelectric signals. References | Related Articles | Metrics

Select

Microstructure and property of Al-1.5Mg-0.3Sc alloy formed by SCR technology Zhang, Xue-Fei (1); Li, Jun-Peng (1); Li, Gang (1); Wen, Jing-Lin (1) 2006, 27 (3):  284-287.  DOI: - Abstract ( 226 )   HTML   PDF (698KB) ( 566 )   The SCR(Shearing-Cooling-Rolling) and conventional casting technology were compared in the preparation of Al-1.5Mg-0.3Sc(wt%), with the effect of trace of Sc addition on the microstructure and property of Al-1.5Mg-0.3Sc(wt%) alloy wire formed by SCR technology investigated. The results showed that the grain of SCR-formed alloy wire is smaller than that of the alloy wire formed conventionally. The latter, after its specimen was metallographically etched, presents the back and irregular lamellar structure at its grain boundaries with some Al3Sc precipitates found at arc boundaries. But, the former, when its specimen was solid solution at 520°C and aged at 320°C for 3 h, its tensile strength is 304 MPa with an elongation 18.9%. It revealed that the SCR-formed alloy wire has higher strength and plasticity. References | Related Articles | Metrics

Select

Chemical reaction in the process of preparing GdB6 with Gd2O3 and B4C Wu, Wen-Yuan (1); Xu, Jing-Yu (1); Sun, Shu-Chen (1); Tu, Gan-Feng (1) 2006, 27 (3):  288-291.  DOI: - Abstract ( 246 )   HTML   PDF (164KB) ( 512 )   The chemical reaction in the process of preparing GdB6 with Gd2O3 and B4C in graphite tube furnace in argon atmosphere was studied. XRD and TG-DTA results showed that the reaction is mainly between the residual impurity C in sample and O2 at the temperature of 367-458°C. In the range from 800°C to 1200°C, there are three reactions in the process, i.e., between Gd2O3 and B4C to produce GdBO3, GdBC and B; among GdBO3 GdBC and B4C to produce GdB4; between Gd2O3 and B4C to produce GdB6. With the rising temperature, the reaction speed of GdB4 increases. The GdB6 is prepared by the reaction of GdB4 with the element B, of which the content of GdB6 is up to 97.8% in 6 h and increases with the prolonged reaction time. References | Related Articles | Metrics

Select

Experimental investigation on effect of oxygen enrichment on erosion of refractories Xu, Ying (1); Hu, Bin-Sheng (2) 2006, 27 (3):  292-295.  DOI: - Abstract ( 279 )   HTML   PDF (286KB) ( 546 )   The erosion process of different refractories was experimentally investigated through modelling the combustion by injecting pulverized coal in BF where the oxygen is enriched. Then, the phase composition and microstructure of such eroded samples of refractory bricks as silica, high-alumina and fireclay bricks were analyzed. The results showed that along with the increasing oxygen content for enrichment, the contents of glassy and aphanitic silicates decrease continuously with expanded pore size and increasing porosity in eroded silica brick and high-alumina brick in which the contents of mullite and cristobalite increase as well. As to the fireclay brick, in which both the phase composition and microstructure show no obvious change. References | Related Articles | Metrics

Select

Effect of complex additive on conductivity of cermet inert anodes Xi, Jin-Hui (1); Yao, Guang-Chun (1); Liu, Yi-Han (1); Zhang, Xiao-Ming (1) 2006, 27 (3):  296-299.  DOI: - Abstract ( 235 )   HTML   PDF (226KB) ( 621 )   To improve the wettability of metallic phase Ag for ceramics so as to make full use of the metallic phase, the additives TiO2 and V2O5 were added to NiO and Fe2O3 powders as raw material in the synthesizing process of Ag/NiFe2O4 cermet containing 10% Ag. The NiO and Fe2O3 powders, Ag and the traces of TiO2 and V2O5 were mixed, then molded and sintered at 1250°C for 6 hr. The effects of TiO2 and V2O5 on the micromorphology and electric conductivity of the cermet were studied. The results showed that when adding TiO2 and V2O5, the metal phase Ag is distributed linearly. EDX analysis showed that there is ceramic phase in the metal phase. The facts show that the complex additives TiO2-V2O5 can improve the wettability between the metallic phase Ag and ceramics with the electric conductivity of samples improved remarkably. It was revealed that when the adding amounts of TiO2 and V2O5 are 0.5% and 2.0% respectively, the conductivity of the sample is 8 times as large as that of the sample without TiO2 and V2O5 additives. References | Related Articles | Metrics

Select

Effect of non-ionic oily additive on precipitate from sodium aluminate solution Chen, Feng (1); Zhang, Bao-Yan (1); Bi, Shi-Wen (2); Chen, Yu-Guo (1) 2006, 27 (3):  300-303.  DOI: - Abstract ( 358 )   HTML   PDF (246KB) ( 588 )   The effects of different amounts of Tween-81 type non-ionic additive on the seeded precipitate from sodium aluminate solution, i.e., Al(OH)3, were studied including its particle strength, size and precipitate rate with the precipitate behavior discussed. The results showed that when the additive concentration in sodium aluminate solution is in the range from 25 to 150 mg/L, the additive can accelerate the crystallization of Al(OH)3 and improve its agglomeration to enable the increases particle size to come into the range from 45 to 75 μm with the number of fine particles reduced and the precipitation rate of the solution increased. The additives was proved available to shape the Al(OH)3 into spherocrystals which are beneficial improving the particle strength. As a whole, the favorable should be 85 mg/L and, as a result, the average particle size of hydrogen alumina is increased by 13 μm with the attrition index reduced by about 25%. References | Related Articles | Metrics

Select

Image orientation recognition based on Hidden Markov Model Yu, Tao (1); Han, Qing-Kai (1); Sun, Wei (1); Wen, Bang-Chun (1) 2006, 27 (3):  304-307.  DOI: - Abstract ( 249 )   HTML   PDF (268KB) ( 651 )   A method of image orientation recognition is put forward, based on HMM (Hidden Markov Model). Segmenting the target image to recognize into sub-images, a singular value decomposition is conducted for them to extract singular value vectors so as to form an observation sequence, i.e., the singular value vectors of the image are taken as HMM observation vectors. Then, the HMM parameters are determined with their maximum likelihood calculated, and the images are recognized according to the clustering which the maximum likelihood of an image to recognize corresponds to. Test results showed that the recognition rate of 150 target images in 3 clusters is up to 85%. References | Related Articles | Metrics

Select

Fuzzy designation based on rough sets for human resource Xu, Feng (1); Yu, Tian-Biao (1); Gong, Ya-Dong (1); Wang, Wan-Shan (1) 2006, 27 (3):  308-311.  DOI: - Abstract ( 239 )   HTML   PDF (879KB) ( 528 )   Analyses the deficiency of conventional designation and introduces the rough sets theory and fuzzy designation of human resource. Then, the fuzzy designation of human resource in the process of developing new products of a company in dynamic alliance is studied. A mathematics model is thus developed, by which the competency indices of technical personnel are reduced attributively with weight coefficients calculated through the theory of variable precision rough sets. In the index attribute, the personal will of technical personnel is considered to make them more active. The index attribute is evaluated fuzzily by experts to form compound matrices in accordance to the weight coefficients based on rough sets. The compound matrices are converted to a single-target decision problem which can be solved by Hungary algorithm. Some numerical examples are given to illustrate the validity of the algorithm proposed and the practicability of the model. References | Related Articles | Metrics

Select

Combinatorial genetic algorithm in optimum design of structure Fan, He (1); Liu, Bin (1); Zhang, Yan-Nian (2); Han, Gui-Wu (1) 2006, 27 (3):  312-315.  DOI: - Abstract ( 207 )   HTML   PDF (978KB) ( 650 )   In view of the shortcomings of simple genetic algorithm, such as premature convergence, random oscillation and slow convergence, some measures are taken to improve them. Generating original population via the ergodicity of chaotic sequence, the optimized results generated from relative difference quotient algorithm are added to the original population to improve its performance. Introduces the fitness scaling to improve traditional fitness function. Relative difference quotient algorithm is strong in local search, while genetic algorithm with a parallel operation is highly effective in global search. To play the role of both advantages, a combinatorial genetic algorithm (CGA) is proposed, taking the relative difference quotient as a genetic operator which is parallel to selection, crossover and mutation and embedded into the improved genetic algorithm so as to upgrade the local optimization ability and avoid premature convergence. A numerical example of a ten-bar truss was given to demonstrate the validity and feasibility of CGA in its application, and it is found that the optimized results of CGA are superior to SGA and IGA. References | Related Articles | Metrics

Select

Approximate algorithm based on generalized inverse matrix theory for rotational response reconstruction Kang, Yu-Mei (1); Bai, Quan (1); Chen, Bai-Ling (1); Liu, Bin (1) 2006, 27 (3):  316-319.  DOI: - Abstract ( 260 )   HTML   PDF (1645KB) ( 550 )   Aiming at the problem that the rotational response is difficult to measure in structural identification, an improved approximate algorithm based on generalized inverse matrix theory is developed for rotational response reconstruction. Starting from the basic equations of static condensation, the algorithm is available to calculate the rotational response in accordance to structural displacement data by solving the generalized inverse matrix. The applicable condition of generalized inverse approximate algorithm and the condition that the generalized inverse solution is just the accurate solution are discussed theoretically and given. Numerical examples are given to illustrate that the norm errors of the approximate algorithm is generally small, while the smaller the absolute value is, the greater the component errors will be. References | Related Articles | Metrics

Select

- - 2006, 27 (3):  320-323.  DOI: - Abstract ( 292 )   HTML   PDF (623KB) ( 654 )   - References | Related Articles | Metrics

Select

- - 2006, 27 (3):  324-327.  DOI: - Abstract ( 311 )   HTML   PDF (187KB) ( 1363 )   - References | Related Articles | Metrics

Select

Upwind difference method for solving the pricing problem of Asian option Zhang, Tie (1); Zhu, Dan-Mei (1) 2006, 27 (3):  328-331.  DOI: - Abstract ( 239 )   HTML   PDF (1608KB) ( 690 )   The kernel of option theory is the option pricing problem. To price the continuously sampled arithmetic average Asian option, an implicit upwind difference scheme is constructed based on the final boundary value problem of partial differential equation, which is satisfiable to the option pricing problem. Then the unique existence and unconditional stability of the difference solution are demonstrated and the error estimate is given under the discrete L2 norm. Some numerical examples are given to show that the numerical method presented is an approximation method with high efficiency and convergence. References | Related Articles | Metrics

Select

Magnon lifetime of two-dimensional insulating ferromagnet at T = 0 K Cheng, Tai-Min (1); Li, Lin (1); Du, An (1); Xianyu, Ze (1) 2006, 27 (3):  332-335.  DOI: - Abstract ( 232 )   HTML   PDF (193KB) ( 527 )   A magnon-phonon interaction model is developed for a two dimensional square insulating ferromagnet. By Matsubara-Green function method, the magnon damping under such on interaction is studied, with the magnon damping calculated on the main symmetric point/line in Brillouin zone for different parameters in the system. It is found that at the boundary of Brillouin zone the magnon damping is strong, while it is very weak in the zone of small wave vectors, and especially the magnon damping becomes maximal at T = 0 K. The influences of longitudinal phonon and transverse phonon on the magnon damping are compared, and the influences of all relevant parameters on magnon damping are also discussed. The expression - Im∑*(1) (k) = /(2τ) is available to take as a criterion for the magnon lifetime. References | Related Articles | Metrics

Select

Representation of object classification curve by dual-energy X-ray transmission technology Yuan, Pei-Xin (1); Sun, Li-Na (1) 2006, 27 (3):  336-339.  DOI: - Abstract ( 266 )   HTML   PDF (159KB) ( 1282 )   Compares the single and dual-energy X-ray transmission technology and analyzes the difference between them. It is found that how the mass attenuation coefficients of two materials change are different even their atomic numbers are the same when the incident energies are different. It implies that when irradiated by dual energy X-ray, i.e., high and low energies are both absorbed, the absorptance of the two materials of the same atomic number are different. Thus the objects which are composed of two different materials/thicknesses or in overlapping image, can be differentiated from each other by way of calculating and comparing the different absorption coefficients as irradiated by low and high energy X-rays. In this way the aluminium plate and polymethyl methacrylate plate are taken as specimens to be tested, and the results show that the boundary curves to classify different materials are reliable. References | Related Articles | Metrics

Select

Obtaining optimized eigenvalue from dual-energy transmission images Sun, Li-Na (1); Yuan, Pei-Xin (1) 2006, 27 (3):  340-343.  DOI: - Abstract ( 184 )   HTML   PDF (154KB) ( 556 )   To classify different materials from the images by dual-energy X-ray transmission, the current method to calculate the Eigenvalue R relating to effective atomic number is combining the high-energy transmission signal with low-energy one. But, the thickness of object affects greatly the R value. So, a ratio of the two transmission signals is proposed to eliminate the effect of object thickness instead, i.e., an optimal numerical computation by which the optimized transmission signals can be obtained through compound Simpson's rule to estimate area absorption coefficient. Analyzing the test data and error probability, the method proposed is proved available to minimize the thickness effect with less mistake, thus improving the veracity in classifying materials. References | Related Articles | Metrics

Select

Vibration response of shrouded blades Guo, Xing-Hui (1); Wei, Wei-Ming (1) 2006, 27 (3):  344-347.  DOI: - Abstract ( 244 )   HTML   PDF (244KB) ( 1195 )   Based on the theory of thin elastic plate, differential equations have been derived for the vibration of three shrouded blades. Further, a dual response equation is given to blade vibration by iterative process for relevant vibration mode. Runge-Kutta numerical method is used to analyze the equations. The vibration response of shrouded blade mainly lies on the holistic natural frequency, the frequency of exciting, the force of exciting. The existence of shrouded brings interaction between every blade, and increases the holistic stiffness of the blades. The result reveals that the natural frequency of blade will increase under the action of shroud. The vibration response of blade presents beat frequency on which there is the influence of the nearby blades. The shroud can alleviate the vibration response of the blade. References | Related Articles | Metrics

Select

FEA simulation of pulling single cord out of fiber-rubber composite at different temperatures Fang, Qing-Hong (1); Wang, Hui-Bin (2); Zhang, Feng-Peng (1); Huang, Bao-Zong (1) 2006, 27 (3):  348-351.  DOI: - Abstract ( 233 )   HTML   PDF (243KB) ( 879 )   The interfacial mechanical properties of fiber-rubber composite were studied at different temperatures with nonlinear FEA to analyze the large deformation of a single cord or fiber that was pulled out of the composite by 2.5 mm. The distribution of normal stress in fiber and interfacial shear stress were obtained as well as the axial pull-out force. The results showed that peak shear stress occurs at the interfacial end and changes with different temperatures. Moreover, the FEA result of pulling-out force showed a good agreement with experimental result at low/moderate temperatures. References | Related Articles | Metrics

Select

Optimum algorithm for large deformation of a cantilever under pressure on free end Zhang, Xu (1); Hou, Xiang-Lin (2); Sun, Feng-Jiu (1); Chen, Chang-Zheng (3) 2006, 27 (3):  352-354.  DOI: - Abstract ( 228 )   HTML   PDF (158KB) ( 553 )   An optimum algorithm is proposed to solve the geometrically nonlinear problem of large deformation of a cantilever under pressure on free end. The cantilever in equilibrium after large deformation is studied. The coordinates of the free end are given through coordinate transformation formulae so as to define an objective function in terms of unknown coordinates of the endpoint. Then, make sure of the optimization problem of the large deformation of the cantilever under pressure on free end. An optimized algorithm is thus programmed for the problem. A typical numerical example is given and the result is analyzed in comparison with that by FEM. It is revealed that the algorithm is reliable in solving the strongly geometrically nonlinear deformation problem, which provides a prospective idea to solve the geometrically nonlinear large deformation problems that are more complex. References | Related Articles | Metrics