基于分层壳单元的RC核心筒结构有限元分析和工程应用

Finite element analysis and engineering application of RC core-tube structures based on the multi-layer shell elements

钢筋混凝土(RC)核心筒是高层建筑中常见的抗侧力结构,其空间受力行为明显,截面形状多样,故准确模拟其非线性受力全过程是结构抗震分析的一个重要课题。分层壳单元根据复合材料原理将壳分成多层,可考虑面内弯曲-面内剪切-面外弯曲之间的耦合作用,能够较全面地反映壳体结构的空间力学性能。基于分层壳单元,对一钢筋混凝土核心筒拟静力试验进行了全过程模拟。通过对墙体、连梁等关键部位合理建模,较好地反映了核心筒的空间受力行为,以及筒体开裂、筒体钢筋屈服、连梁屈服和剪切破坏等复杂非线性行为,计算结果和试验结果吻合良好。运用该核心筒模型,对某实际高层框架-核心筒结构进行弹塑性分析,表明了模型的实用性。基于分层壳的核心筒模型可以较好地模拟核心筒的各项力学性能,在筒体结构大震弹塑性分析方面具有一定参考意义。

As one of the most widely used lateral resistant structures, reinforced concrete （RC） core tube consists of diverse forms of members and exhibits spatial mechanical behaviors. How to accurately simulate the RC tubes in the process of nonlinear performance is an important problem in seismic analysis of the structures. Based on the muhi-layer shell elements, the process simulation of a pseudo-static testing on RC core tubes is presented. By correctly modeling the key parts （such as walls, coupling beams, and reinforcements）, the numerical model is capable of simulating the spatial behavior of the tube as well as the complicated nonlinear behavior, such as yielding and shear failure of the coupling beams, cracking of the tube. Results from the simulation match well with those from the tests. An elastoplastic analysis of a framed core-tube structure is conducted to illustrate the implementation of proposed model.