Lateral Stiffness of Frames and Effective Length of Framed Columns
Publication: Journal of Structural Engineering
Volume 120, Issue 5
Abstract
After obtaining shear force, which creates unit lateral displacement in columns of a framed system, from an assumed deformation shape, the lateral‐stiffness value of a related story is obtained. By employing these lateral‐stiffness values, a system lateral‐stiffness matrix, which is in banded matrix form, can be established easily. By using this banded matrix, established through the aforementioned method, natural angular frequency and characteristic model shape can be easily obtained. Also presented is a method to calculate the effective length of framed columns by using factors, which depend on the stiffnesses of columns and girders of the framed system. First‐mode values calculated by the presented method are compatible with classic shear‐beam solutions and exact solutions. Furthermore, results obtained from the application of factors, giving effective length factors for various end‐connection conditions at the far ends of columns, are on the conservative side compared with exact values.
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Copyright © 1994 American Society of Civil Engineers.
History
Received: May 28, 1993
Published online: May 1, 1994
Published in print: May 1994
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