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自由曲面结构不仅要具备良好的建筑表现力也要保证其受力合理性。利用自由曲面结构形态创建的非均匀有理B样条-梯度法(NURBS-GM)得到典型的凹凸自由曲面作为研究对象,制作混凝土壳体模型结构并进行静力试验研究。结果表明:弯曲应力在正负高斯曲率过渡区与支座附近较大,但整个结构主要仍以薄膜应力的形式抵抗荷载,随着荷载的增加薄膜应力分布有所变化,特别是正负高斯曲率过渡区变化较显著。上表面裂缝在正负高斯曲率过渡区出现并向支座附近发展,下表面则基本是加载点附近裂缝的连线并延伸至支座附近。整个加载过程中,裂缝出现较晚,但数量较多,最终在加载点附近发生局部强度破坏。荷载-位移曲线在弹性阶段斜率较大,并有较长的塑性发展段。采用ABAQUS有限元分析软件对试验模型进行有限元模拟并与实测数据进行对比,二者吻合较好。
Free-form surface structure not only must have a good architectural expression but also to ensure its force rationality. By using the non-uniform rational B-spline-gradient method (NURBS-GM) created by the free-form surface structure model, a typical concave-convex freeform surface is obtained as the research object, and the concrete shell model structure is fabricated and studied. The results show that the bending stress is larger near the transition region between the positive and negative Gaussian curvature and the support, but the whole structure mainly resists the load in the form of film stress. The stress distribution of the film changes with the increase of load, especially the positive and negative Gaussian curvature The transition area changes significantly. The upper surface cracks appear in the transition zone of positive and negative Gauss curvature and develop near the support. The lower surface is basically the connection of cracks near the loading point and extends to the vicinity of the support. During the whole loading process, the cracks appeared later, but the quantity was more, finally the local strength destruction occurred near the loading point. The load-displacement curve has a large slope in the elastic phase and a long plastic development. The ABAQUS finite element analysis software is used to simulate the experimental model and compared with the measured data, the two agree well with each other.