A new hybrid MMA-MGCMMA （HMM） algorithm for solving topology optimization problems is presented. This algorithm combines the method of moving asymptotes （MMA） algorithm and the modified globally convergent version...A new hybrid MMA-MGCMMA （HMM） algorithm for solving topology optimization problems is presented. This algorithm combines the method of moving asymptotes （MMA） algorithm and the modified globally convergent version of the method of moving asymptotes （MGCMMA） algorithm in the optimization process. This algorithm preserves the advantages of both MMA and MGCMMA. The optimizer is switched from MMA to MGCMMA automatically, depending on the numerical oscillation value existing in the calculation. This algorithm can improve calculation efficiency and accelerate convergence compared with simplex MMA or MGCMMA algorithms, which is proven with an example.展开更多
In complex engineering optimization, multilevel or two-level approaches are often applied. These approaches are carried out in assumption that there are no connections among sub problems at the same level. But it is d...In complex engineering optimization, multilevel or two-level approaches are often applied. These approaches are carried out in assumption that there are no connections among sub problems at the same level. But it is difficult to construct the models that suit to this assumption. In recent years, the complexity of engineering systems has led to the rapid development in the field of Multidisciplinary Design Optimization (MDO). In MDO, two kinds of coupled factors, coupled variables (or functions) and system (or global) variables, always exist among all disciplines. These variable5 or functions make it disordered to solve the whole system. So, how to handle these variables is one of important studies in MDO. In this paper two approaches are discussed for handling these coupled factors in non-hierarchic system in MDO. And a test engineering example gives a demonstration about the implemeniation of these approaches.展开更多
Reinforcement detail drawings are one important part of the design of hydraulic structures and the important basis of construction and management. However, the efficiency of the traditional creation of engineering dra...Reinforcement detail drawings are one important part of the design of hydraulic structures and the important basis of construction and management. However, the efficiency of the traditional creation of engineering drawings is very low and the workload is heavy. There is no satisfactory software for hydraulic engineering because of the irregularity and diversity of hydraulic structures' shape. An automatic generation system of reinforcement detail drawings for hydraulic structures is introduced. Its functions and modules are introduced first. The related technologies such as automatic driensioning are discussed in detail. At the end of the paper, an example is given.展开更多
The dynamic and consistent information association among vtrious application activities in the full life cycle of a product is a key to the assurance of the cooperation among different application domains. In order to...The dynamic and consistent information association among vtrious application activities in the full life cycle of a product is a key to the assurance of the cooperation among different application domains. In order to establish and maintain the association, a design-process-based product association model was proposed. This model takes advantage of the generic naming mechanism, the private protocol for history-based form feature modeling, on which the Data Association Protocol is built. Hence the model can provide the way of constructing and maintaining the information linkage among different product developing stages naturally and dynamically while keeping the privacy of the feature coding. A case study illustrates the utilities of the model in the data linking between design model and process planning model.展开更多
基金This project is supported by National Basic Research Program of China(973Program, No.2003CB716207) and National Hi-tech Research and DevelopmentProgram of China(863 Program, No.2003AA001031).
文摘A new hybrid MMA-MGCMMA （HMM） algorithm for solving topology optimization problems is presented. This algorithm combines the method of moving asymptotes （MMA） algorithm and the modified globally convergent version of the method of moving asymptotes （MGCMMA） algorithm in the optimization process. This algorithm preserves the advantages of both MMA and MGCMMA. The optimizer is switched from MMA to MGCMMA automatically, depending on the numerical oscillation value existing in the calculation. This algorithm can improve calculation efficiency and accelerate convergence compared with simplex MMA or MGCMMA algorithms, which is proven with an example.
文摘In complex engineering optimization, multilevel or two-level approaches are often applied. These approaches are carried out in assumption that there are no connections among sub problems at the same level. But it is difficult to construct the models that suit to this assumption. In recent years, the complexity of engineering systems has led to the rapid development in the field of Multidisciplinary Design Optimization (MDO). In MDO, two kinds of coupled factors, coupled variables (or functions) and system (or global) variables, always exist among all disciplines. These variable5 or functions make it disordered to solve the whole system. So, how to handle these variables is one of important studies in MDO. In this paper two approaches are discussed for handling these coupled factors in non-hierarchic system in MDO. And a test engineering example gives a demonstration about the implemeniation of these approaches.
文摘Reinforcement detail drawings are one important part of the design of hydraulic structures and the important basis of construction and management. However, the efficiency of the traditional creation of engineering drawings is very low and the workload is heavy. There is no satisfactory software for hydraulic engineering because of the irregularity and diversity of hydraulic structures' shape. An automatic generation system of reinforcement detail drawings for hydraulic structures is introduced. Its functions and modules are introduced first. The related technologies such as automatic driensioning are discussed in detail. At the end of the paper, an example is given.
文摘The dynamic and consistent information association among vtrious application activities in the full life cycle of a product is a key to the assurance of the cooperation among different application domains. In order to establish and maintain the association, a design-process-based product association model was proposed. This model takes advantage of the generic naming mechanism, the private protocol for history-based form feature modeling, on which the Data Association Protocol is built. Hence the model can provide the way of constructing and maintaining the information linkage among different product developing stages naturally and dynamically while keeping the privacy of the feature coding. A case study illustrates the utilities of the model in the data linking between design model and process planning model.
