Showing papers by "Thomas K. Caughey published in 1960"
TL;DR: In this article, the necessary and sufficient conditions under which both discrete and continuous damped linear dynamic systems possess classical normal modes were determined for both continuous and discrete linear systems, respectively.
Abstract: The purpose of this paper is to determine necessary and sufficient conditions under which both discrete and continuous damped linear dynamic systems possess classical normal modes.
884 citations
258 citations
TL;DR: In this article, an analysis of the response of a system with bilinear hysteresis to random excitation is made, and it is shown that for moderately large inputs, the additional damping created by the biliniear hystresis decreases the mean squared deflection compared with that for a linear system with the same viscous damping.
Abstract: An analysis is made of the response of a system with bilinear hysteresis to random excitation. It is shown that for moderately large inputs, the additional damping created by the bilinear hysteresis decreases the mean squared deflection compared with that for a linear system with the same viscous damping. However, for large inputs, the decrease in the stiffness of the system due to the bilinear hysteresis causes the mean squared deflection to increase over that for the equivalent linear system.
228 citations
22 citations
TL;DR: In this article, a number of errors appear in Sec. III which invalidate both that section and Sect. IV, thus invalidating both sections and the paper's entire body.
Abstract: Dr. Samuels [1] is to be congratulated on a most interesting paper. It is unfortunate that a number of errors appear in Sec. III which invalidate both that section and Sect. IV.
16 citations
7 citations
01 Jan 1960
TL;DR: In this paper, the design of a response spectrum analyzer for earthquake excitation studies is described, with a series inductance, capacitance, and resistance circuit forming a direct analog to the mechanical structure.
Abstract: The design of a response spectrum analyzer for earthquake excitation studies is described. Electric analog techniques are used, with a series inductance, capacitance, and resistance circuit forming a direct analog to the mechanical structure. The circuit arrangement permits a determination of system response for a sequence of periods at constant damping. Provision is made for obtaining zero damping in the circuit. An arbitrary function generator of the variable width film-photoelectric cell type is described. The results obtained with the function generator-spectrum analyzer system for a half-sine wave pulse are compared with the mathematically obtained exact answers for the zero damping case, and the accuracy of the system is shown to be satisfactory.
This is a revision of a report originally issued as the "Sixth Technical Report", Office of Naval Research Contract N6 ONR-244, Task Order 25, Project Designation NR-081-095 by the California Institute of Technology dated July, 1954. The new model spectrum analyzer herein described has superseded the model discussed in this preceding report.
6 citations