Applied Mechanics and Materials Vols. 34-35

Abstract: distributed data mining is widely used in industrial and commercial applications to analyze large datasets maintained over geographically distributed sites. This paper discusses the disadvantages of existing distributed data mining systems, and puts forward a distributed data mining platform based grid computing. The experiments done on a data set showed that the proposed approach produces meaningful results and has reasonable efficiency and effectiveness providing a trade-off between runtime and rule interestingness.

Abstract: This research is to find a design method for the large scale and complex product system. Thus, we made an approach to possibly better solution with limited time, limited resources and limited costs. This paper aims to find a method to quantify the solving process of the first stage in the concurrent design – “task decomposition”, in order to make preparations necessary for the next two stages -“concurrent task process” and “convergent coordination”. According to product's functional unit, we first decentralized complex product system into sub-modules. Then determine the importance and coherence among these sub-modules by using analytic hierarchy (AHP). Combining the results of the two judgments, we further classify the sub-modules to form distributed sub-systems, so that different design teams can work more effectively and more efficiently during their respective period. Finally, we verify the usefulness and effectiveness of the distributed method with an example of design task decomposition in servo press.

Abstract: Expanded graphite treated with silane coupling agent (DB-171) was incorporated into PDCPD to explore its tribological features. Chemically treated expanded graphite (TEG)/PDCPD composites were prepared by a simulating reaction injection molding (SRIM) system. The friction and wear properties of TEG/PDCPD composites were investigated on a block-on-ring tribological tester under dry sliding condition. Experimental results show that the friction coefficients of PDCPD composites increase slightly, and the wear volume losses of the PDCPD composites reduce significantly with the loading of treated expanded graphite. The addition of only 0.3wt% chemically treated expanded graphite contributes to dramatic improvement of wear resistance of PDCPD, and the wear volume loss reduces by 71.2% compared with pure PDCPD. Scanning electron microscopy (SEM) was utilized to study the worn surfaces of PDCPD composites, and the friction and wear mechanisms were discussed.

Abstract: In order to design a reliability test bed for train brake system, theory of vibration equivalence was used to represent in laboratory the environmental vibration. Firstly, the root mean square (RMS) value of the acceleration was calculated for train brake system according to IEC 61373. Then, a configuration of vibrostand was proposed for the reliability test bed, which was mainly composed of vibrating table-board, vibrator motor, damp and four vibrating springs, as shown in figure 2. After that, an equation was got according to the RMS equivalency theory. Finally, the equation was solved according to the feature of the vibrostand. And the quantitative relation was got for exciting force F0, shock excitation circular frequency ω and spring rate k. The method can also be used on other occasions where sinusoidal vibration is needed to replace random vibration.

Abstract: As the market competition became more fiercely and the customers’ needs of diversified products increased, small and medium enterprises (SME) were more and more aware of the importance of getting quick respond of the market. More and more enterprises felt the logistics cost pressure during this business. How to lower down the logistics cost especially the stock cost became crucial for these SME enterprises. Further more, for enterprises whose producing type is many varieties small batches, how to use valid method to decline inventory and waste, is a great hard nut to crack. This article targeted on inventory control of clothing manufacturing enterprises for research, RFID technology was applied in stock management, optimization method was adopted for inventory control based on RFID, optimization control model was built, and the route for declined inventory cost and waste was analyzed. Finally, the application method was verified according emulation.

Abstract: The relationships among equivalent elastic modulus of porous titanium alloy / HA coating composite were investigated by using finite element method in this paper. The method of porosity and pore shape of bio-derived bone scaffold materials was ascertained by the elastic modulus of natural bone. The equivalent elastic modulus of porous titanium alloy / HA coating composite decreased with increasing porosity, decreased with the increase of fractal dimension of porosity space, and increased with the increase of fractal dimension of solid matrix. If the porosity ranged from 40% to 50% and pore/solid fractal dimension ranged from 2.77 to 2.96, the equivalent elastic modulus of porous titanium alloy / HA coating composite was consistent with the elastic modulus of natural bone when the bio-derived bone scaffold materials were fabricated by porous titanium alloy / HA composite coating materials.

Abstract: To analyze the influence of the nonlinearity of the floating raft vibration isolation system, the theory of flexible multibody dynamics was used here to model the rigid-flexible coupling nonlinear floating raft vibration isolation system. The dynamical characteristics of the model were studied with ADAMS software and some typical nonlinear phenomena, such as subharmonics, superharmonics and attractor coexistence, were observed through time domain analysis.

Abstract: To ensure the safety and the production efficiency as well as the component lifetime of deep-sea mining system, a novel heave compensation system of deep-sea mining based on dynamic vibration absorber was proposed in the light of 5000m deep sea poly-metallic mining system of China in this paper. According to the work condition of heave compensation system, the response of deep-sea mining ship under random wave of sea state 4 in China’s deep sea poly-metallic mining field are numerically simulated in time domain. The proposed heave compensation system was simplified to a two-degree-of-freedom system stimulated by the displacement motion of the deep-sea mining ship and its dynamic model was built. Taking the minimum of the displacement variance of the proposed heave compensation system as the optimal object and considering the allowed displacement of the dynamic vibration absorber itself, the computation formula of the optimum parameters of dynamic vibration absorber for heave compensation system of deep-sea mining is derived. Thus the parameter of dynamic vibration absorber was determined and its effect on the performance index of the heave compensation system was simulated and compared. The dynamic vibration absorber with optimum parameters was simulated and tested on the test bench of double-storey mass-spring vibration system in the lab. The results of the example show that the performance of vibration control of the designed dynamic vibration absorber is satisfactory and the computational formulas given in the paper are effective. The results also verified that the heave compensator based on dynamic vibration absorber with the optimal parameters can have good performance of heave compensation and it is practical to isolate the lifting pipeline and its deployment platform from the vibration of the ship motion induced by the irregular wave with simplicity and less energy consumption. This work in the paper will be of great theoretical guidance in the optimum design of the dynamic vibration absorber for heave compensation system of deep-sea mining.

Abstract: It is known that vibratory feeders are the most versatile of all hopper feeding devices for small engineering parts and play a key role in assembly automation. This work develops a mathematical model of the part motion in vibratory feeding, from which how the part works can be better known. A computer simulation programmed with MATLAB has been made to predict the conveying velocity of the parts in vibration feeding system, and furthermore, experiments have been carried out for verification purpose. The experimental results show that the simulation results are reasonable, and hence can be used to improve the design of vibratory feeding system.

Abstract: A new method is presented to investigate the globally asymptotic stability of reaction-diffusion cellular neural network with time-delays. The method is built on the mean Lyapunov function. We give some new sufficient conditions on time-dependent or time-independent to ensure globally asymptotic stability of the equilibrium point of the class of systems under the conditions of the active functions are continuous by employing linear matrix inequality (LMI). The results extend and improve the earlier works of other researchers. In additions, examples are given to show the application of the established stability theorems.