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Journal of Chinese
            Architecture and Urbanism                                           RuiXue Multi-Hall in reciprocal structures



              There are two fundamental methods for generating 3D   stationary in the X and Y directions, allowing for a seamless
            meshes for reciprocal structures on shell surfaces. The first   fit with the shell surface.
            method involves initially dividing the overall surface into   An algorithm  is introduced to generate  geometric
            three-dimensional quadrilaterals or hexagons, followed by   prototypes  of reciprocal  grids.  With input  parameters,
            conducting a structural transformation of the reciprocal   including the base figure mesh number, the reciprocal
            mesh in space. While this approach is simple and intuitive,   transformation angle, and the optimized shell surface,
            it imposes stringent requirements on the original geometric   this algorithm can rapidly and effortlessly produce the
            surface and can only support regular polygon meshing   reciprocal structure by transforming any grid at any angle.
            (Figure 10).
                                                               Subsequently, the reciprocal structure can be efficiently
              The second method entails utilizing the shell surface   applied to the shell surface, creating a preliminary shape
            as the parent body and then executing a rotation mapping   reference (Figure 11).
            from the plane element onto the shell’s parent body. This   Four fundamental grids, labeled as B, C, F, and G, have
            method guarantees that the reciprocal geometry remains
                                                               been chosen for comparison. Grids B and C exhibit distinct
                                                               geometric characteristics and boast excellent construction
                                                               feasibility. On the other hand, grids F and G are comprised
                                                               simple triangles and quadrilaterals, exhibiting a balanced
                                                               scale. The initial geometric edge length for all four grids is
                                                               set at 1.2 m. Following the installation of graphic inlays, a
                                                               reciprocal geometric transformation is employed to achieve
                                                               a relatively moderate structural scale and mechanical effect
                                                               (Figures 12 and 13).
                                                                 For comparison purposes, rotation angles α of 15° and
                                                               30°  have been  selected. However, in  the  case  of  grid  B,
                                                               which lacks structural reciprocal properties when rotated
                                                               by 30°, a 45° rotation is employed for scheme comparison.
                                                               The estimation of material consumption is based on a rod
                                                               element with a cross-section of 400×200 (Figure 14).

                                                                 In  summary,  following  the  reciprocal  support
                                                               transformation, the structural units within the grid,
            Figure 9. Spatial grid transformation. Source: Drawing by Yingzi Hu  comprised triangles and squares in both F and G, expand




























            Figure 10. Unit beam generated by the particle-spring method (left) and unit beam generated by the angle-preserving mapping method (right). Source:
            Drawing by Yingzi Hu


            Volume 6 Issue 2 (2024)                         9                        https://doi.org/10.36922/jcau.1635
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