Morphopoiesis Research For Plane Frame Structure

Frame structures which are widely used in engineering is characterized byflexible spatial arrangement, light weight, flexible compare with the architecturallayout and so on. However, there are many negative aspects for frame structures,such as node stress concentration, force transmission path is not directly, the lateralstiffness is smaller, lateral deformation is greater when under lateral loads so theframe structure belongs to flexible structure. Recent years, along with theimprovement of people’s living standards and substantial increase in the level ofproductivity people constantly challenged to more space and greater height whichmakes the disadvantage of frame structures more prominent. How to improve lateralstiffness of frame structures and controlling the lateral size is the main researchdirection as to optimization of frame structures. The defect of frame structures canbe improved by structural concept design and structural optimization. In this paper,the mechanical properties of the frame structures can be improved by structuraloptimization.In this article, the morphosis technique for plane frame structures is based onstrain energy on the sensitivity of nodal coordinates and unit strain energy density.The size of strain energy sensitivity is the maximum rate of change of strain energyand its orientation point to the direction that the strain energy increased maximum,the strain energy can be reduced by mobile node in the opposite direction ofsensitivity. Unit strain energy density which can be used as the evaluation index ofunit bearing efficiency means the strain energy that stored in the cell.This text the morphosis technique for plane frame structures is established byusing the finite element method to calculate strain energy sensitivity of the node andunit strain energy density of the initial structures. Based on the nature of the strainenergy sensitivity and unit strain energy density can progressively adjusts the nodecoordinate vector, increase or eliminate unit. The mechanical properties of the planeframe structures can be improved by using this method to morphogenesis.In this paper models of plane frame structures under different loadingconditions and different space constraints are regarded as examples to examine theevolution of shapes and the variation of mechanical properties, and thecharacteristics of the method were summed up at last. In the process of evolution thestiffness increases, the moment of the structure has also been significantly reducedwhich means the main force of the structure changed from moment to axial force.The method has the advantage of simple operation, strong controllability, fastevolution and so on. Effectiveness of the established method can be proved by example analysiswhich can provide an effective method for plane frame structural morphogenesis. Aseries of plane frame structures with distribution lever and direct force transmissionpath can be obtained by using this method that have important reference significancefor the architectural design and structural concept design.