Spatial Geometric Nonlinear Analysis Method Based on Tension-Compression and Torsion-Warping Stability Interpolation Function

摘要

Conception and computational formula on torsion-warping stability function is brought forward for the first time. Based on the theory of continuum mechanics, geometric nonlinear analysis FEM model of multistorey and high-rise lightweight spatial steel frame was established considering shearing deformation effect according to stability interpolation function. Making use of updated Lagrangian formulation, starting from increment virtual work equilibrium equation, the explicit expresses of beam-column elements' stiffness matrix for spatial steel construction framing was derived. Meanwhile, the model on beam-column theory of geometric nonlinear analysis of multistorey and high-rise spatial steel frame was also discussed considering shearing deformation effect according to stability interpolation function. Conception and computational formula on torsion-warping stability function is brought forward for the first time, based on tension-bending model. For the first time the torsion-warping tangent stiffness matrix of bi-axisymmetric open thin-wall and lightweight beam-column element is derived, based on torsion-warping stability interpolation function, and at the same time spatial geometric tangent stiffness matrixes for beam-column element of lightweight steel structure based on tension-compression and torsion-warping stability interpolation function is presented for the first time.