This paper presents a bi-level hybrid local search(BHLS)algorithm for the three-dimensional loading problem with balancing constraints(3DLP-B),where several rectangular boxes with even densities but different sizes ar...This paper presents a bi-level hybrid local search(BHLS)algorithm for the three-dimensional loading problem with balancing constraints(3DLP-B),where several rectangular boxes with even densities but different sizes are loaded into a single cubic bin to meet the requirements of the space or capacity utilization and the balance of the center of gravity.The proposed algorithm hybridizes a novel framed-layout procedure in which the concept of the core block and its generation strategy are introduced.Once the block-loading sequence has been determined,we can load one block at a time by the designed construction heuristic.Then,the double-search is introduced;its external search procedure generates a list of compact packing patterns while its internal search procedure is used to search the core-block frames and their best distribution locations.The approach is extensively tested on weakly to strongly heterogeneous benchmark data.The results show that it has better performance in improving space utilization rate and balanced condition of the placement than existed techniques:the overall averages from 79.85%to 86.45%were obtained for the balanced cases and relatively high space-usage rate of 89.44%was achieved for the unbalanced ones.展开更多
There are many structural lateral systems used in tall buildings： rigid frames, braced frames, shear walls, tubular structures and core structures. The outrigger and belt truss systems are efficient structures for dr...There are many structural lateral systems used in tall buildings： rigid frames, braced frames, shear walls, tubular structures and core structures. The outrigger and belt truss systems are efficient structures for drift control and base moment reduction in tall buildings where the core alone is not rigid enough to resist lateral loads. Perimeter columns are mobilized for increasing the effective width of the structure, and they developed tension in the windward columns and compression in the leeward columns. Optimum locations for the outriggers have been studied because of the influence on the top displacement and base moment in the core. It was analyzed the optimal position for two to seven outriggers and belt trusses, aiming to achieve minimum bending moment and minimum drift.展开更多
基金Project(16B134)supported by Hunan Provincial Department of Education,China
文摘This paper presents a bi-level hybrid local search(BHLS)algorithm for the three-dimensional loading problem with balancing constraints(3DLP-B),where several rectangular boxes with even densities but different sizes are loaded into a single cubic bin to meet the requirements of the space or capacity utilization and the balance of the center of gravity.The proposed algorithm hybridizes a novel framed-layout procedure in which the concept of the core block and its generation strategy are introduced.Once the block-loading sequence has been determined,we can load one block at a time by the designed construction heuristic.Then,the double-search is introduced;its external search procedure generates a list of compact packing patterns while its internal search procedure is used to search the core-block frames and their best distribution locations.The approach is extensively tested on weakly to strongly heterogeneous benchmark data.The results show that it has better performance in improving space utilization rate and balanced condition of the placement than existed techniques:the overall averages from 79.85%to 86.45%were obtained for the balanced cases and relatively high space-usage rate of 89.44%was achieved for the unbalanced ones.
文摘There are many structural lateral systems used in tall buildings： rigid frames, braced frames, shear walls, tubular structures and core structures. The outrigger and belt truss systems are efficient structures for drift control and base moment reduction in tall buildings where the core alone is not rigid enough to resist lateral loads. Perimeter columns are mobilized for increasing the effective width of the structure, and they developed tension in the windward columns and compression in the leeward columns. Optimum locations for the outriggers have been studied because of the influence on the top displacement and base moment in the core. It was analyzed the optimal position for two to seven outriggers and belt trusses, aiming to achieve minimum bending moment and minimum drift.
