FINITE-ELEMENT NONLINEAR-ANALYSIS OF STRESSED-ARCH FRAMES

The paper describes a nonlinear analysis that can be applied to study the strength and behavior of stressed-arch frames. The unique feature of the structural system is the way the arches are erected without the use of cranes or scaffolding but by the use of a posttensioning process. For some highly curved structures, the top chord may be plastically deformed during the erection procedure. The finite-element nonlinear analysis was developed to simulate the geometric nonlinear behavior and plasticity in the stressed-arch, particularly the top chord. The paper describes the nonlinear analysis including the arch elements used, the implementation of plasticity, and the iterative strategies employed to solve the nonlinear problem. A series of tests on panels removed from the stressed-arch frames, which have been described in earlier papers and reports, is simulated using the nonlinear analysis to verify its accuracy for application to stressed-arch frames. A brief description of the application of the nonlinear analysis and panel tests to complete systems is also provided in the paper.