NEHRP Clearinghouse

Title
A Timoshenko Beam Model for Vibration of Plane Frames.
File
PB274935.pdf
Author(s)
Sun, C. T.; Chen, C. C.; Bogdanoff, J. L.; Lo, H.
Source
National Science Foundation, Washington, D.C. Research Applied to National Needs., June 3, 1976, 42 p.
Abstract
A detailed dynamic analysis, reported in this series, was conducted on the seismic response and structural safety of key subsystems (steam generator, high pressure steam piping, coal handling equipment, cooling tower, chimney) of Unit no. 3 of TVA at Paradise, Kentucky in order to: (1) determine for the key components the natural frequencies below 50 Hz and the corresponding normal modes; (2) determine response of plant to seismic disturbances; (3) verify through full scale tests results obtained in (1) and determine estimates of damping needed in (2); (4) determine potential failure modes of major structural components; and (5) determine a spare parts policy for a power system so that outages due to damage from seismic disturbances are minimal. Analytical and experimental methods are used. This volume includes discussion of the use of the Timoshenko beam model with bending and shear rigidities evaluated by a procedure that takes the joint rotation into account in a quasi-static manner. Explicit formulas for bending and shear rigidities of the model are derived in terms of the member dimensions and material properties of the original frame structure. A shear beam model is derived from the Timoshenko beam model. Solutions for three evaluative examples are presented and compared with exact finite element solutions.
Keywords
Dynamic structural analysis; Seismic waves; Ground motion; Bending; Earthquake engineering; Kentucky; Earthquakes; Vibration; Shear stresses; Finite element analysis; Structural members; Steam electric power generation; Earth movements; Paradise (Kentucky); Framed structures; Timoshenko method