The ICM method with objective function transformed by variable discrete condition for continuum structure

ICM （Independent Continuous Mapping） method can solve topological optimization problems with the minimized weight as the objective and subjected to displacement constraints. To get a clearer topological configuration, by introducing the discrete condition of topological variables and integrating with the original objective, an optimal model with multi-objectives is formulated to make the topological variables approach 0 or 1 as near as possible, and the model reduces the effect of deleting rate on the result. The image-filtering method is employed to eliminate the checkerboard patterns and mesh dependence that occurred in the topology optimization of a continuum structure. The computational efficiency is enhanced through selecting quasi-active displacement constraints and a design region. Numerical examples indicate that this algorithm is robust and practicable, though the number of iterations is slightly increased with respect to the original algorithm.

Network Structure Optimization Method for Urban Drainage Systems Considering Pipeline Redundancies

Redundancy is an important attribute of a resilient urban drainage system.While there is a lack of knowledge on where to increase redundancy and its contribution to resilience,this study developed a framework for the optimal network structure of urban drainage systems that considers pipeline redundancies.Graph theory and adaptive genetic algorithms were used to obtain the initial layout and design of the urban drainage system.The introduction of additional water paths(in loop)/redundancies is suggested by the results of complex network analysis to increase resilience.The drainage performances of the urban drainage system with pipeline redundancies,and without redundancies,were compared.The proposed method was applied to the study area in Dongying City,Shandong Province,China.The results show that the total overflow volume of the urban drainage system with pipeline redundancies under rainfall exceeding the design standard(5 years) is reduced by 20-30%,which is substantially better than the network without pipeline redundancies.

Topology optimization of support structure of telescope skin based on bit-matrix representation NSGA-II

Non-dominated sorting genetic algorithm II（NSGA-II）with multiple constraints handling is employed for multi-objective optimization of the topological structure of telescope skin,in which a bit-matrix is used as the representation of a chromosome,and genetic algorithm（GA）operators are introduced based on the matrix.Objectives including mass,in-plane performance,and out-of-plane load-bearing ability of the individuals are obtained by fnite element analysis（FEA）using ANSYS,and the matrix-based optimization algorithm is realized in MATLAB by handling multiple constraints such as structural connectivity and in-plane strain requirements.Feasible confgurations of the support structure are achieved.The results confrm that the matrix-based NSGA-II with multiple constraints handling provides an effective method for two-dimensional multi-objective topology optimization.