Research On Morphogenesis Technologies Of Shell Mesh Hybrid Structure System

With the continuous updating and development of architectural space struct ure technology,architecture is no longer a material entity that simply provides space,but a complex behavior that embodies science,philosophy,art and technology.The innovation of contemporary architecture and structural form is also a comprehensive result based on the development of various disciplines.Compared to the traditional space structure,net shell hybrid structural system on the one hand,to maximize the implementation of the new type of architectural design intentions,fusion of smooth continuous curved surface structure,flexible design has a free style of architecture form,on the other hand,in the form of grid structure can satisfy the complex building structure,have smooth force,force uniform,such as excellent mechanical properties,At the same time,it inherits the characteristics of strong spanning ability and has a better reflection on the overall stiffness.This paper will focus on the morphological creation method of shell-net hybrid structure system as the core content,and carry out research work in the following aspects.(1)Combined with the geometric forming technology,the method of morphology creation and modeling of the shell-mesh hybrid structure system is proposed.The creation of the initial structural model is the key factor to determine the direction of the creation of the structural form.During the creation process,not only the geometric information of the building should be set,but also the corresponding structural and operational information should be set.In this paper,the parameter B-spline theory is used to complete the generation of the superstructure shell elements,and the basic elements such as trigon,quadgon and spatial cross truss are used to complete the formation of the substructure grid system.Finally,the initial structure model which is convenient for the study of the shell net mixed structure system morphology creation method is established through combination.(2)The finite element analysis program of shell-rod hybrid element was compiled to analyze the sensitivity of strain energy to nodes.Since the initial structure contains two different types of structural elements,namely shell element and rod element,this paper,based on the characteristics of the same degree of freedom of rod element and shell element node,compile the shell-rod mixed element finite element analysis program to replace the single finite element analysis technology.This paper also deduces the sensitivity of strain energy to free moving link and free surface constrained link,which lays a foundation for the following research work.(3)In this paper,a method of structural morphology creation was established for the hybrid system of curved shell and grid structure.Structural strain energy is a comprehensive index to measure the overall mechanical properties.Based on the relationship between strain energy and node position,a mathematical model for the morphological creation of shell net mixed structure system is established,and a morphological creation method for shell net mixed structure system is proposed.This method is to realize the change of "shape" by moving the node position,and then achieve the optimization of the overall "state" of the structure,and finally realize the method of minimizing the strain energy.In this paper,a simple example model is used to track the change law of the model shape and the corresponding displacement,axial force,bending moment and other mechanical quantities in the evolution process,and the characteristics of the method and the final mechanical properties of the structure are summarized.At the same time,the effectiveness and practicability of the program compiled by FORTRAN language are verified.The feasibility of applying this method in engineering cases is also discussed,and the application method of shell and net hybrid structure system morphology creation method in practical engineering is proposed.The numerical example shows that the overall stiffness is significantly improved after the optimization of the structural model,the internal forces of the shell and the bar are redistributed,and the bending moment is resisted in a more reasonable form,and the shell-bar cooperatively transfers the load.The proposed method has good practicability.