Static And Dynamic Performance Analysis And The Shape Optimization Design Of Conical Reticulated Shell

The reticulated shell structures have many advantages such as attractive appearance,reasonable stress,high rigidity,light weight etc.It is widely used in large public buildings such as sports and art venues,high-speed rail stations and waiting halls.This paper takes the conical reticulated shell with the Chinese architectural style as the research object,based on the different types of reticulated shell surfaces and architectural styles.Six types of single-layer conical reticulated shell model can be established by using APDL(Ansys Parametric Design Language)language.It can also explore its static and seismic performance,and shape optimization design.The main tasks include:(1)The design macro program of six types of conical reticulated shell including Ribbed,Schwedler,Lamella,Kiewitt,Three-way grid and Geodesic was established according to the geometric characteristics of the conical reticulated shell,and referring to the types and modeling method of spherical shell by using APDL language.Only need to input the macroscopic geometric parameters(S?f?Kn?Nx)of the conical reticulated shell to realize the automatic modeling of such shell quickly,which provides great convenience for structural modeling,static and dynamic analysis and shape optimization design of such shell.(2)According to the calculation data of various rod lengths of the reticulated shell formed by the modeling process and slenderness ratio requirements of"Specifications for design of steel structures"GB 50017-2003,combined with the division method of shell member,the reasonable range of the number of meshes(Kn,Nx)under different cross-sectional area of the member is given.This provides a useful reference for optimization parameters selection and engineering applications of reticulated shells.(3)The static performance comparison of six single-layer conical reticulated shells was performed(Ribbed and Three-way grid are better),under the uniform load of2.35KN/m~2(considering the weight of the structure).The influence of five parameter changes such as structural span S,the vector height f,the number of the circumferential zone number Kn,the number of radial node turns Nx of the reticulated shell on the structural mechanical properties was explored.This provides a reference for subsequent structural design and application.(4)The shape optimization design on Ribbed and Kiewitt conical reticulated shells was carried out by using two-stage sequence optimization algorithm.The total steel consumption of the structure is the lowest,under the condition of satisfying the constraints of strength,stiffness,and stability of the structural members,joints,and the overall structure.The optimal combinations of Kn and Nx are obtained for 168 examples of different geometric parameter combinations.It reduces the project cost and provides a basis for the application in practical projects.(5)Taking the Kiewitt and the three-way grid as examples,the response analysis is performed.The natural vibration frequency and corresponding vibration pattern of the structure are given respectively,and analyzing the variation law of the natural vibration frequency of the structure.The time-history analysis method was used to analyze the seismic characteristics of reticulated shell structures under the action of the EL-CENTRO triaxial earthquake.Exploring the effects of span,vector height,and grid number on the natural frequency and maximum displacement of structure.The displacement time history curve is drawn,which gives the general law of the seismic response of the cone-shaped reticulated shell.This provides a certain reference for the seismic design of this structure..