Abstract
This paper deals with eigen frequencies for L shaped frame under gravity. Because the frame was consisted of two flexible beams having extremely thin thickness, the shapes of the structures were changed due to their self-weight. And the two ends of the L shaped frame were assumed as being clamped. Discrete equations using finite element in consideration with geometrical nonlinearity were derived as cubic simultaneous nonlinear differential equations. First, large static deformations of the frame due to gravity were calculated using the proposed FEM. And then, linear natural frequencies for the deformed structures were investigated. The calculated results using the FEM were consistent with the experimental results. Further, the influences of self-weight on eigen frequencies of the L shaped frame were clarified.
