Local multiscale finite element method for mechanical analysis of beam-column joint in long-span column-free underground station
The Gangxia North comprehensive transportation hub has a column-free design in the range of atrium 51.2 m×48.0 m in the core transfer area,and its long-span is the first case in China.The beam-column joint is crucial for force transmission,but the joint has the features of large quantity and complex types,and the multiple system transformations are involved during the construction.It is essential to ensure smooth force transmission through joints.Based on multiple points constraints(MPC)method,the local multiscale finite element method(LMFEM)was proposed.The example demonstrates that,by using LMFEM,the influence of the through mode on the mechanical performance of typical beam-column joint was investigated.Combined on-site monitoring,the measured values of joint stress state was compared and analyzed with the calculated values of different methods.The results show that,compared with the traditional local refined finite element method(LRFEM),LMFEM has smaller modeling workload,its boundary condition is easier to satisfy the Saint Venant principle,and it can balance computational accuracy and efficiency.The column-through joint has lower stress level,smooth force transmission and insignificant stress concentration.This is more suitable for Gangxia North large-span column-free underground structure.For the same modeling scale and mesh size,the maximum relative error between the calculated value of LRFEM2 model and measured value is 11.8%,and the maximum relative error between the calculated value of LMFEM model and measured value is 12.5%.However,the LMFEM model has a significantly lower quantity of nodes and a shorter computation time.Compared with LMFEM,the computational accuracy of the LRFEM is more sensitive to the boundary condition and mesh size.The LMFEM has the advantages of high computational accuracy,fast computational efficiency,and is easy to specify the boundary conditions,which can analyze the force performance of joints in large and complex engineering structures.
local multiscalebeam-column jointthrough modelong-span column-free structuremesh sizeboundary condition
万方数据
维普
