Parametric Modeling And Shape Optimization Of Five Typical Double-layer Cylindrical Lattice Shell

Spatial structure can fully utilize the structure form of itself and select suitable material to meet the changeable building structure modeling, so as to provide more space. In recent years, Computer technology has make a spurt of progress in the development of structural simulation, which makes the spatial structure of a new breakthrough in the study and optimization of the structure form, in the perfect combination with the combination of structure form, stress analysis, optimization.Mainly for the modeling and optimization analysis of five typical double-layer cylindrical latticed shell. The first is written the corresponding program by using APDL language, realized the parametric modeling of double layer cylindrical reticulated shell in five forms. Among them, four kinds of the ventral rod connection are established. Respectively, cross truss system, four pyramidal system, four pyramidal of normally partial members omitted system and four pyramidal of reverse partial members omitted system.Based on the parametric modeling, for different cylindrical form, abdominal rod connection mode, span, length, number of grid, the ratio of rise to span under the influence of parameter of double-layer cylindrical lattice shell, the use of ANSYS post processing function of static analysis, obtained under the different forms of double layer cylindrical reticulated shell structure displacement, stress, internal forces of rod, and the results analysis, summarizes the corresponding rules.Based on the static analysis, the shape optimization of different double layer cylindrical reticulated shell structure. In the double-layer cylindrical reticulated shell structure, node coordinates generated is regular, it is decided by the cylindrical surface shape, namely determined by the cylindrical reticulated shell structure, the length of span, rise-span ratio, span direction on the grid number, the length direction of the grid number, shell thickness. The changeable node coordinate as the shape optimization design variables, to get the different coordinates of the nodes through changing geometric parameters value of control shell shape. Therefore, the shape optimization can first determine the geometric parameters, namely the cylindrical reticulated shell form, using the section optimization method corresponding to find the optimal section of the form, on the basis of this by changing geometric parameters for multiple optimization, making the structure until the minimum total weight of global optimal structure.Using FORTRAN language to compile the program with ANSYS connected, forming the modeling, analysis, optimization of the coherence. The optimization process of the grid number, rise-span ratio as the optimization variables. To cross truss system and the system is put four pyramid forms of five kinds of double layer cylindrical reticulated shell, analysis of the span from30to90m, rise-span ratio from1/3to1/7, and quadrangular pyramid of normally partial members omitted system and quadrangular pyramid of reverse partial members omitted system analysis of the span from30to50m, rise-span ratio from1/3to1/7, with the the shape optimization analysis to get the conclusions.