QR－METHORD FOR NONLINEAR ANALYSIS OF TALL FRAMES

The nonlinear analysis of structure is tightly related to the economy and safety of civil engineering. This paper studied the material nonlinear problems, geometric nonlinear problems and double nonlinear problems, which includes both material and geometric nonlinear problems, of tall frames. At first I built up the stiffness equations of nonlinear problems by QR-method, then solved them by incremental iterative method, finally wrote the corresponding programs by C and calculated some examples. This method avoids the shortcomings and great difficulties of the traditional methods such as finite elements method. The results showed that this method is simple and has high precision; it has great value in practices. This paper is valuable not only in theory but also in practices.