Modularity is the key to improving the cost-variety trade-off in product development. To achieve the functional independency and structural independency of modules, a method of clustering components to identify module...Modularity is the key to improving the cost-variety trade-off in product development. To achieve the functional independency and structural independency of modules, a method of clustering components to identify modules based on functional and structural analysis was presented. Two stages were included in the method. In the first stage the products’ function was analyzed to determine the primary level of modules. Then the objective function for modules identifying was formulated to achieve functional independency of modules. Finally the genetic algorithm was used to solve the combinatorial optimization problem in modules identifying to form the primary modules of products. In the second stage the cohesion degree of modules and the coupling degree between modules were analyzed. Based on this structural analysis the modular scheme was refined according to the thinking of structural independency. A case study on the gear reducer was conducted to illustrate the validity of the presented method.展开更多
The study was done for high pressure adsorption of methane on microporous carbons, which has an ANG vehicular application background. Adsorption isotherm of methane on super activated carbon up to 6 MPa was measured a...The study was done for high pressure adsorption of methane on microporous carbons, which has an ANG vehicular application background. Adsorption isotherm of methane on super activated carbon up to 6 MPa was measured and isosteric heats of methane adsorption on a number of microporous carbons were determined from adsorption isosteres by the Clausius Clapeyron equation. The variation of the isosteric heats of adsorption with the amount of methane adsorbed was discussed.展开更多
Dynamic investigations revealed that lower order harmonic resonance phenomenon exists in the three ring gear transmission. That is, when the input speed is close to 1/3, 1/6, 1/9,…, 1/3 n of the primary natural frequ...Dynamic investigations revealed that lower order harmonic resonance phenomenon exists in the three ring gear transmission. That is, when the input speed is close to 1/3, 1/6, 1/9,…, 1/3 n of the primary natural frequency of the transmission, the loads on the bearings and gears are especially high. This paper explained this phenomenon from the viewpoint of parametric resonance in terms of perturbation technique. A conclusion was drawn that the basic reason for this phenomenon is the primary resonance caused by forcing excitation and parametric resonance caused by parametric change.展开更多
The rubber circular plate is considered as a kind of membrane. Based on the character that there exists no bending moment inside a membrane, the geometric behavior of the rubber circular plate in expanding state was d...The rubber circular plate is considered as a kind of membrane. Based on the character that there exists no bending moment inside a membrane, the geometric behavior of the rubber circular plate in expanding state was described with the aid of a group of mathematic method. The relationship between deflection and load was attained by means of calculating stress and strain inside the curved surface of rubber plate. Meantime, based on Hencky method, the relationship between deflection and load was attained and considered as the Hencky solution. The different results given rise by the two different resolving methods were compared. The deviation results from the Hencky method was discussed, and a kind of correcting method was put forward.展开更多
基金National Basic Research Programme of China (973 Program) (No. 2003CB317005)Key Project of Chinese Ministry of Educa-tion (No. 105065)
文摘Modularity is the key to improving the cost-variety trade-off in product development. To achieve the functional independency and structural independency of modules, a method of clustering components to identify modules based on functional and structural analysis was presented. Two stages were included in the method. In the first stage the products’ function was analyzed to determine the primary level of modules. Then the objective function for modules identifying was formulated to achieve functional independency of modules. Finally the genetic algorithm was used to solve the combinatorial optimization problem in modules identifying to form the primary modules of products. In the second stage the cohesion degree of modules and the coupling degree between modules were analyzed. Based on this structural analysis the modular scheme was refined according to the thinking of structural independency. A case study on the gear reducer was conducted to illustrate the validity of the presented method.
文摘The study was done for high pressure adsorption of methane on microporous carbons, which has an ANG vehicular application background. Adsorption isotherm of methane on super activated carbon up to 6 MPa was measured and isosteric heats of methane adsorption on a number of microporous carbons were determined from adsorption isosteres by the Clausius Clapeyron equation. The variation of the isosteric heats of adsorption with the amount of methane adsorbed was discussed.
基金Partly supported by the Open Fund of theState Key Lab.of Mechanical TransmissionChongqing U niv
文摘Dynamic investigations revealed that lower order harmonic resonance phenomenon exists in the three ring gear transmission. That is, when the input speed is close to 1/3, 1/6, 1/9,…, 1/3 n of the primary natural frequency of the transmission, the loads on the bearings and gears are especially high. This paper explained this phenomenon from the viewpoint of parametric resonance in terms of perturbation technique. A conclusion was drawn that the basic reason for this phenomenon is the primary resonance caused by forcing excitation and parametric resonance caused by parametric change.
文摘The rubber circular plate is considered as a kind of membrane. Based on the character that there exists no bending moment inside a membrane, the geometric behavior of the rubber circular plate in expanding state was described with the aid of a group of mathematic method. The relationship between deflection and load was attained by means of calculating stress and strain inside the curved surface of rubber plate. Meantime, based on Hencky method, the relationship between deflection and load was attained and considered as the Hencky solution. The different results given rise by the two different resolving methods were compared. The deviation results from the Hencky method was discussed, and a kind of correcting method was put forward.
