将土-结构动力相互作用问题引入到空间结构的抗震研究中,以ANSYS为上部空间结构计算平台;以FORTRAN为下部结构的计算平台,采用集中质量显式有限元和透射人工边界模拟地基无限域,建立包含土、基础、空间结构在内的整体三维模型,采用显-隐式相结合的方法进行时程分析,从而建立一种空间结构-地基动力相互作用的三维时域直接分析方法。可以采用不同的时间步距分别计算上部、下部结构,以提高计算效率;空间结构的非线性可通过较为成熟的ANSYS有限元软件进行考虑。通过集中质量模型和四点支承正放四角锥网架算例,验证了该方法的可行性和正确性。
A three-dimensional numerical analytical method in time domain for the soil-spatial structure dynamic interaction is proposed. The spatial structure is modeled by ANSYS software, and the unbounded soil is modeled by the lumped-mass finite element and transmitting boundary. The three-dimensional integral model that includes the soil, foundation and spatial structure is developed. The explicit-implicit integration scheme is used, and the efficiency can be greatly improved by using different time steps in the soil and structural analysis, The nonlinear influence of spatial structures can be taken into account in ANSYS software. A lumped mass model and a four-point-supported square pyramid space grid are researched and the results confirm the feasibility and validity of the method.