05.13: Efficient static and dynamic analysis of steel frames by one-element-per-member models

ABSTRACT This paper proposes an efficient numerical analysis technique for static and dynamic analysis of space steel frames by one‐element‐per‐member model, considering material and geometric nonlinearities including P‐Δ‐δ effects, large global deflections and member deformations. The curved arbitrarily‐located‐hinge (ALH) beam‐column element is developed for capturing members' behaviours and simulating initial imperfections. Unlike the conventional plastic hinge element requiring two and more elements to capture the locations of plastic hinge along member length, which causes certain difficulties to model member initial imperfections, one proposed element per member is sufficient. The plastic hinges are simulated as gradually softening springs and the corresponding formulae are presented. The additional degrees of freedom in the element are condensed so that it can be easily incorporated into the existing software with dramatic improvement on numerical efficiency and accuracy. The consistent element mass matrix is derived based on the Hermite interpolation function, and the Rayleigh damping model is adopted for representing the system viscosity. Verification examples are given to validate the present model in simulating inelastic yielding and dynamic behaviours of the steel frames and members under loads. One distinct feature of the research is to propose an effective analytical framework using high‐performance elements, dramatically improving the numerical efficiency and making the method being practical.