This paper presents a procedure to optimize the porosity of parapets to improve the aerodynamic behavior of low‐rise buildings with flat roofs, by coupling an optimization algorithm and computational fluid dynamics (CFD) simulations. The performance of solid parapets to decrease the wind suctions on flat roofs induced by conical vortices was firstly studied, based on four turbulence closure models (standard k‐ε, RNG k‐ε, SST k‐ω, and RSM). The simulation results were validated by comparing with the wind tunnel data. Additionally, the porous parapet was treated as a momentum sink in the governing momentum equation, and the RSM turbulence model was employed. As a result, six optimization studies focusing on the highest mean suction minimization that consider parapet height were presented. The aim of this paper is to search for the best performing porosity through an automatic CFD‐based optimization methodology. At low relative heights (h_p/H = 0.01∼0.05, h_p is the parapet height, and H is the roof height), the porous parapet with optimal porosity in between 38.2% and 52.3% seems to be more effective than solid parapets in attenuating high corner suctions generated by conical vortices; however, the solid parapet gives the best performance in the reduction of wind suctions when h_p/H ≥ 0.07.

A simultaneous shape and stacking sequence optimization algorithm is presented for laminated composite free‐form shells, by which the coupled effect of shape and stacking sequence can be considered. The optimization objective is determined as maximizing fundamental natural frequency to obtain largest stiffness of shells. Nonuniform rational B‐spline (NURBS) is employed to represent free‐form geometrical shapes. The coordinates of NURBS control points and fiber orientations are set up as continuous and discrete optimization variables, respectively, and optimized simultaneously. To improve the efficiency of the mixed continuous‐discrete optimization, multi‐island genetic algorithm (MIGA) is employed to search for the global result. Through several numerical examples, the performance of the proposed approach is demonstrated in comparison with the two‐phase optimization method; the effect of boundary conditions and the setup of control points on optimal results are investigated, respectively.

With the increasing application of a sustainable development concept in the construction industry, green construction technology has been widely used in the construction stage of architectural projects which promoted the development of construction engineering in China. Green construction has been an irresistible trend of the constructional industry development all over the world. This paper studies the fundamental connotation of green building construction, illustrates the significance and meaning of green construction and analyzes the green construction principles. Then, the useful green construction technical measures will be put forward in order to provide reference for researchers and engineers. Finally, the actual project is introduced as an example to demonstrate the application and management measures to minimize pollution, reduce natural resource consumption, and create environmentally friendly, energy-saving green buildings. The main elements of green construction, work art and requirements of green construction application and management, occupational health and safety management measures are illustrated as well.

This paper presents a procedure to optimize the rise‐to‐span ratio of single‐layer reticulated cylindrical roofs to improve their aerodynamic performance, by coupling the optimization method with computational fluid dynamics (CFD) and finite element analysis (FEA). Four turbulence models (standard k‐ε, RNG k‐ε, SST k‐ω, and RSM) were used to predict the mean wind loads on cylindrical roofs. The simulation results were compared with wind tunnel data, and the RSM turbulence model was employed. The aim of this paper is to determine the best performing rise‐to‐span ratio of cylindrical roofs based on the gradient algorithm. Two objective functions were considered to minimize the highest mean suction on the roof surface and the maximum response displacement of the single‐layer reticulated cylindrical shell subjected to mean wind loads. The results revealed that a cylindrical roof with a rise‐to‐span ratio (R/S) of 1/6.25 seems to be most effective in attenuating high suctions on the roof surface. In addition, a single‐layer reticulated cylindrical shell with R/S = 1/5.5 gives the best performance in reducing the maximum response displacement against wind loads.

This work investigates the natural vibration characteristics of free-form shells when considering the influence of uncertainties, including initial geometric imperfection, shell thickness deviation, and elastic modulus deviation. Herein, free-form shell models are generated while using a self-coded optimization algorithm. The Latin hypercube sampling (LHS) method is used to draw the samplings of uncertainties with respect to their stochastic probability models. ANSYS finite element (FE) software is adopted to analyze the natural vibration characteristics and compute the natural frequencies. The mean values, standard deviations, and cumulative distributions functions (CDFs) of the first three natural frequencies are obtained. The partial correlation coefficient is adopted to rank the significances of uncertainty factors. The study reveals that, for the free-form shells that were investigated in this study, the natural frequencies is a random quantity with a normal distribution; elastic modulus deviation imposes the greatest effect on natural frequencies; shell thickness ranks the second; geometrical imperfection ranks the last, with a much lower weight than the other two factors, which illustrates that the shape of the studied free-form shells is robust in term of natural vibration characteristics; when the supported edges are fixed during the shape optimization, the stochastic characteristics do not significantly change during the shape optimization process.

Uncertain errors induced in construction process could affect the stability of free-form shells. Considering shell thickness deviation, the stochastic characteristics of buckling loads are investigated using Latin hypercube sampling coupled with Newton-Raphson method. In addition, a sensitivity analysis is conducted to quantize the effect of the thickness deviation on buckling loads of free-form shells.