Masahisa SUZUKI


A Study of Accuracy and Convergence of Geometrical Nonlinear Analysis of
Structural Framed Members


adviser : Eiji Iwasaki,Masatsugu Nagai


In structural framed members composed of long and narrow beams, finite
displacement occurs. In these structures, to calculate of displacements
and resultant forces need to take account of the influcence of changing
geometric configuration. This is called geometrical nonlinear analysis.


In this study, I used updated Lagrange approach and total Lagrange
approach as geometric nonlinear analysis. This study is only different
from formulation, and other are the same condition.


By numerical analysis, the accuracy and the convergence are obtained in
the following result;

* numerical results contain a lot of errors when incremental size is
large, However, high accurate solutions are obtained when incremental
size is small,

* when large strain occurs, results between updated Lagrange approach
and total Lagrange approach are different,

* updated Lagrange approach is obtained under a small number of
iteration, and it is better than total Lagrange approach.