This paper investigates the influence of crack orientation on damage quantification using Lamb wave in plate structures. Finite element simulation is performed to acquire Lamb wave signal responses for different confi...This paper investigates the influence of crack orientation on damage quantification using Lamb wave in plate structures. Finite element simulation is performed to acquire Lamb wave signal responses for different configurations of crack orientations and crack lengths. Two Lamb wave features, namely the normalized amplitude and the phase change, are used as damage sensitive features to develop a crack size quantification model. A hypothesis based on the geometrical influence on signal features is proposed, and the crack size quantification model incorporating the orientation angle is established using the hypothesis. An index of Probability of Reliable Quantification(PRQ) is proposed to evaluate the performance of the model. The index can be used to determine the sizing risk in terms of probabilities. A realistic aluminum plate is used to obtain the experimental data using piezoelectric(PZT) wafer-type sensors around a center through crack. The experimental data are used to validate the overall method. Results indicate that the proposed model can yield reliable results for size quantification of inclined cracks.展开更多
To solve the difficulty in describing the generic bill of material (GBOM) with the conventional tabular structure in a relational database system,a novel XML-based approach is presented to represent GBOM. It can repre...To solve the difficulty in describing the generic bill of material (GBOM) with the conventional tabular structure in a relational database system,a novel XML-based approach is presented to represent GBOM. It can represent and maintain one generic structure that encompasses all variants of a product. With the combination of product-oriented notation,this approach further gives a high degree of flexibility to support the user in the product variant specification task. The generic BOM system is then introduced for the particular product variant,and a prototype system has been developed. It is indicated that the presented approach is feasible.展开更多
In order to meet the requirement of network synthesis optimization design for a micro component, a three-level information frame and functional module based on web was proposed. Firstly, the finite element method （FE...In order to meet the requirement of network synthesis optimization design for a micro component, a three-level information frame and functional module based on web was proposed. Firstly, the finite element method （FEM） was used to analyze the dynamic property of coupled-energy-domain of virtual prototype instances and to obtain some optimal information data. Secondly, the rough set theory （RST） and the genetic algorithm （GA） were used to work out the reduction of attributes and the acquisition of principle of optimality and to confirm key variable and restriction condition in the synthesis optimization design. Finally, the regression analysis （RA） and GA were used to establish the synthesis optimization design model and carry on the optimization design. A corresponding prototype system was also developed and the synthesis optimization design of a thermal actuated micro-pump was carded out as a demonstration in this paper.展开更多
This paper analyzes the state of the art of partner selection and enumerates the advantage of partner selection based on gray relation analysis comparing to the other algorithms of the partner selection. Furthermore, ...This paper analyzes the state of the art of partner selection and enumerates the advantage of partner selection based on gray relation analysis comparing to the other algorithms of the partner selection. Furthermore, partner selection system based on gray relation for an Agile Virtual Enterprise（AVE） is analyzed and designed based on the definition and characteristics of the AVE. According to J2EE mode, the architecture of the partner selection system is put forward and the system is developed t^ing JSP, EJB and SQL Server. The paper lays emphasis on a gray relational mathematic model, AVE evaluation infrastructure, a core algorithm of partner selection and a multi-layer gray relation selection process.展开更多
基金supported by Science Challenge Project of China (No. TZ2018007)National Natural Science Foundation of China (Nos. 11872088 and51975546)。
文摘This paper investigates the influence of crack orientation on damage quantification using Lamb wave in plate structures. Finite element simulation is performed to acquire Lamb wave signal responses for different configurations of crack orientations and crack lengths. Two Lamb wave features, namely the normalized amplitude and the phase change, are used as damage sensitive features to develop a crack size quantification model. A hypothesis based on the geometrical influence on signal features is proposed, and the crack size quantification model incorporating the orientation angle is established using the hypothesis. An index of Probability of Reliable Quantification(PRQ) is proposed to evaluate the performance of the model. The index can be used to determine the sizing risk in terms of probabilities. A realistic aluminum plate is used to obtain the experimental data using piezoelectric(PZT) wafer-type sensors around a center through crack. The experimental data are used to validate the overall method. Results indicate that the proposed model can yield reliable results for size quantification of inclined cracks.
文摘To solve the difficulty in describing the generic bill of material (GBOM) with the conventional tabular structure in a relational database system,a novel XML-based approach is presented to represent GBOM. It can represent and maintain one generic structure that encompasses all variants of a product. With the combination of product-oriented notation,this approach further gives a high degree of flexibility to support the user in the product variant specification task. The generic BOM system is then introduced for the particular product variant,and a prototype system has been developed. It is indicated that the presented approach is feasible.
基金Projects 50375118,5014006 supported by the National Natural Science Foundation of China
文摘In order to meet the requirement of network synthesis optimization design for a micro component, a three-level information frame and functional module based on web was proposed. Firstly, the finite element method （FEM） was used to analyze the dynamic property of coupled-energy-domain of virtual prototype instances and to obtain some optimal information data. Secondly, the rough set theory （RST） and the genetic algorithm （GA） were used to work out the reduction of attributes and the acquisition of principle of optimality and to confirm key variable and restriction condition in the synthesis optimization design. Finally, the regression analysis （RA） and GA were used to establish the synthesis optimization design model and carry on the optimization design. A corresponding prototype system was also developed and the synthesis optimization design of a thermal actuated micro-pump was carded out as a demonstration in this paper.
文摘This paper analyzes the state of the art of partner selection and enumerates the advantage of partner selection based on gray relation analysis comparing to the other algorithms of the partner selection. Furthermore, partner selection system based on gray relation for an Agile Virtual Enterprise（AVE） is analyzed and designed based on the definition and characteristics of the AVE. According to J2EE mode, the architecture of the partner selection system is put forward and the system is developed t^ing JSP, EJB and SQL Server. The paper lays emphasis on a gray relational mathematic model, AVE evaluation infrastructure, a core algorithm of partner selection and a multi-layer gray relation selection process.
