The multi-objective collaborative optimization problem with multi-objective subsystems has a bi-level optimization architecture, that consists of the system and subsystem levels. Combining the multi-objective optimization algorithm with a bi-level optimization structure can obtain a satisfactory solution. Given that the preference-based algorithm requires minimal running time, the Linear physical programming (LPP) method, one of the typical preference-based algorithms, is adopted. Considering that setting the preference values for the incompatibility function is difficult, the weighted incompatibility function is added to the piecewise linear function of the LPP model. An expression of dynamic weight is also presented according to the inconsistency among the subsystems, which is caused by the sharing and auxiliary variables relative to the different subsystems. Using an engineering example, this study reveals that the interdisciplinary consistency is satisfactory when the dynamic weight is used in the LPP model, which thereby demonstrates the effectiveness of the presented method.
Due to the stable hysteretic behavior, buckling‐restrained braces (BRBs) have been increasingly adopted in reinforced concrete (RC) frame structures to develop a dual structural system (BRB‐RCF). This study proposed an alternative strength‐based design approach that decomposes the dual BRB‐RCF system into two independent RC frame and BRB system using the BRB‐carrying story shear ratio. The design of RC frame is performed in an integrated manner by considering the BRB postyielding force demands. Three RC frames with five, 10, and 15 stories were employed as prototype structures, and seven story shear ratios ranging from 0.1 to 0.7 were used to generate a total of 21 structural modes. The material usage, maximum axial compression ratio of columns, and elastic interstory drift ratio were compared for different story shear ratios. Nonlinear dynamic analysis of the BRB‐RCFs subjected to 12 ground motions were carried out. The seismic response including the maximum interstory drift ratio, hysteretic energy dissipation ratio, and actual BRB‐carrying story shear ratio were systematically assessed for different design story shear ratios. Based on the considerations of material usage and seismic performance, it is suggested that the design BRB‐carrying story shear ratio should be in the range of 0.3 to 0.5. 相似文献
Bulletin of Engineering Geology and the Environment - The mechanism of lagging water inrush in underground tunnel constructions due to the proximity of a karst cavern with confined water is... 相似文献