Research On Morphogenesis Technique For Ruled Surface Shell Structures

The architectural design gradually develops towards the direction of freedom,flexibility and diversification.It has higher and higher requirements on the structure,which poses many difficulties to the structural design.In particular,the free surface,large-span spatial structure is very important to the rationality of the structure of the mechanical properties.In many cases,it decides the success or failure of architectural design for to meet the intent of free-form surface buildings,on the one hand,it needs to make sure that the rationality of structure mechanics performance,on the other hand,it is necessary to solve the construction performance,restrain the construction difficulty and reduce the construction cost to the greatest extent.The previous research is more about how to realize the mechanical rationality on the basis of satisfying the architectural intention and few studies have been made to solve a series of problems caused by construction performance.Ruled surface is a special free surface composed of a curved conductor and a linear bus.As the bus line is straight,the construction difficulty and the possibility of construction cost are greatly reduced.At the same time,through flexible wire setting,architecture with free and flexible style can be designed.Based on the geometrical characteristics of the ruled surface,the method of structuring the shell with ruled surface,which takes into account the construction performance,architectural intention and mechanical rationality,is studied in this paper.In order to meet the requirements of practical engineering,the method of generating multiple wires using b-spline curve to create straight curved surface and different times of wire connection and wire branch method is studied.On this basis,the arrangement scheme of conductor and conductor control point with combined ruled surface,different times of setting,branch opening means is discussed.In further,the method of generating the initial shell structure with different forms of complex ruled surface is studied.The shape of the ruled surface depends on the shape of the wire expressed by the b-spline curve.In particular,the structure shape and mechanical performance of the complex shell formed by the combination of multiple ruled surfaces are closely related to the arrangement of wires,the number and position of wire control points.During the study,we seize the control points of b-spline curve setting and characteristics of the wire,analyze the control points with other vertical stripes of any point on the surface of the relation,the relation between the structural strain energy and control point position.The sensitivity of the strain energy of the structure to the control point is derived,which lays a foundation for the establishment of the method of the shape creation of the ruled surface structure.Structural strain energy is one of the comprehensive indexes to measure the overall performance of structural morphology.According to the relationship between the structural strain energy and the structural shape of the striated plane,a mathematical model of the structural morphology of the striated plane with the control point of the b-spline curve of the striated plane as the design variable and the structural strain energy as the design objective is established.On this basis,the influence of the change of control points on the strain energy of the structure is further studied,and a new method for the reasonable structural configuration of the surface is proposed,which can reflect the geometric characteristics of the surface.FORTRAN computer language is used to compile the corresponding program.At the same time,the validity and reliability of the method are verified by a simple example,and the calculation steps are summarized.Taking different types of initial ruled surface structure as the research object,the change characteristics of method performance in complex structure processing,shape and mechanical properties in the process of shape creation were further investigated,and the final structure shape and stress characteristics obtained were discussed,and the characteristics of the method were summarized.The shell structure of the ruled surface not only has enough overall stiffness,maximally restrains the generation of bending moment,but also transfers load in the way of film stress.In order to further explore the feasibility of the application of the method in practical project design,the application process of the method is expounded,and the simulation of different types of building engineering examples is carried out.The proposed method can realize the rationality of both mechanical performance and construction performance as well as the unique architectural style of ruled surface.In order to solve the problem of high construction difficulty of free-form surface,the method can be converted into ruled surface to reduce the construction difficulty and construction cost.Finally,on the basis of verifying the improvement degree of structural mechanical properties,the whole process curve of load-displacement under different initial conditions is obtained by using ANSYS universal software,the characteristics of instability are analyzed,and the instability law is summarized.The method proposed in this paper has high optimization efficiency and mechanical rationality because a small number of control points are selected as design variables.It creates a reasonable structure to reduce the difficulty and cost of construction.From the perspective of architecture,its shape has a unique style different from other free-form curved buildings.