Research On Morphogenesis Technique Of Free-form Architectural Epidermal Structure

In recent years,architectural design has been dominated by free and complex curved surfaces,which has brought many challenges to structural design.Especially in the design of architectural skin form,curved skins with different shapes and boundary forms are increasingly presented to the world.Under this background,people have made a lot of investigations on the building skin in terms of building functions and intelligence;while in terms of structure,a creative solution is needed,on the one hand,it can easily express various complex surface skin shapes to meet the shape Requirements;on the other hand,it is necessary to consider the rationalization of the structure,and can well integrate the requirements of the skin shape on the architectural function.Based on the above reasons,in this paper,in order of morphological expression,mathematical modeling,mechanical optimization and result analysis,the mechanical creation and optimization methods of free-form surface structure are studied.Building skins generally have complex geometric shapes.In terms of the mathematical description of curved surfaces,they often reflect the characteristics of multi-valued functions and multiple times.For the convenience of representation,this paper uses the parameter B-spline theory to construct the skin shape of a single free-form building with different times.On this basis,the continuous splicing conditions between various types of B-spline surfaces were constructed,including boundary condition processing,parameter domain coincidence processing,hole processing and variable number processing,etc.,and further created the initial freedom using surface splicing as a carrier The method of generating the surface morphology of curved surfaces can meet the needs of various skin morphologies that may exist in architectural practice.After giving the skin morphology certain mechanical model information,this paper establishes a mathematical model that takes the coordinates of key points on the skin structure as design variables and the strain energy of the skin structure as the objective function,and calculates the strain energy and strain energy sensitivity of the initial skin structure.In view of the characteristics of the slow convergence speed of the first-order node adjustment method,this paper uses the second-order node adjustment method to optimize the shape of the skin structure;at the same time,this paper proposes a step size that combines the golden section method and the step size reduction Choosing a plan makes up for the shortcomings of determining step size based on experience in the past,and improves optimization efficiency.The reliability of the method was tested through several calculation examples,and the characteristics of the method and the mechanical properties of the structure obtained by the method were summarized.In addition,this article studies the strategy of using the method.The selection strategy of continuous spliced surfaces in the description of the building skin,the node variable selection strategy and the strategy of mechanical optimization and building function coordination are given so that the method can be better applied in actual engineering.In addition,this paper also analyzes the ultimate bearing capacity of the skin structure before and after optimization,and further analyzes the effect of initial defects on the ultimate bearing capacity of the structure by analyzing the load-displacement curve of the structure under nonlinear conditions.The results show that during the optimization process,the ultimate bearing capacity of the table structure gradually increases,and the resulting structure is not sensitive to initial defects,so that the structure obtains good stability.