Final Report

AASHO Road TestHighway Research BoardNational Academy of Sciences - National Research Counci

A Method for Calculating the Natural Frequencies of Continuous Beams, Frames, and Certain Types of Plates

Office of Naval Research. Department of the Navy.Contract N6ori-71, Task Order VI, Project NR-064-18

A Simple Approximation for the Fundamental Frequencies of Two-Span and Three-Span Continuous Beams

A rapid approximate method is presented for calculating the fundamental frequencies of flexural vibration of two-span beams and of particular arrangements of three-span beams which are continuous over non-deflecting supports and are elastically restrained against rotation at their end supports. The end restraints may be provided by actual coil springs or they may represent the effect of adjoining members, but in all cases the stiffnesses of these restraints are assumed to be positive. The mass per unit of length and the flexural rigidity of the beams may vary from one span to the next, but in any one span these quantities are considered constant. Two numerical examples are included to illustrate the application of the method.Office of Naval Research. Department of the Navy.Contract N60ri-071(06), Task Order VI, Project NR-064-18

A Simple Approximation for the Natural Frequencies of Partly Restrained Bars

Office of Naval Research. Department of the Navy.Contract N6ori-71, Task Order VI, Project NR-064-18

A Method for Calculating the Natural Frequencies of Continuous Beams

This report describes a method for calculating the undamped natural frequencies of flexural vibration of elastic beams which are continuous over non-deflecting supports. Numerical values of the quantities of "dynamic flexural stiffness" and of "the product of dynamic flexural stiffness and dynamic flexural carry-over factor" which are necessary in the analysis by this method are tabulated in the Appendix. The method is illustrated by a numerical example.Office of Naval Research. Department of the Navy.Contract N6ori-71, Task Order VI, Project NR-064-18

Issued as a Part of the Tenth Progress Report of the Highway Bridge Investigation

The Division of Highways. State of Illinois.The U.S. Department of Commerce. Bureau of Public Roads

Analysis of Static and Dynamic Response of Simple-Span Multigirder Highway Bridges

The Division of Highways. State of Illinois.The U.S. Department of Commerce. Bureau of Public Roads

Response of Arches Under Dynamic Loads

Research Directorate, Air Force Special Weapons Center. Kirtland Air Force Base.Contract AF 29(601)-2591Project 108

Issued as Part of the Tenth Progress Report of the Highway Bridge Impact Investigation

The results of an analytical investigation are presented to illustrate the nature of the dynamic effects produced by moving vehicles in highway bridges of the cantilever type. In the analysis the bridge is represented by a beam with distributed flexibility and seven concentrated point masses, and the vehicle is represented by a smoothly moving, single-axle, sprung load. The parameters investigated include the speed of the vehicle, the stiffness of the vehicle suspension in comparison to the stiffness of the bridge, and the limiting interleaf friction in the springs of the vehicle. It is shown that cantilever bridges are more susceptible to vibration than continuous bridges of the same general proportions.The Division of Highways. State of Illinois.The U.S. Department of Commerce. Bureau of Public Roads

Tables of Deflection and Moment Coefficiencies for the Steady-State Vibration of Uniform Bars

Tabulated in this report are numerical values for the following quantities: (a) coefficients of steady-state deflection for a uniform bar, fixed at one end and subjected to a harmonically varying deflection without rotation at the other end, and (b) coefficients of steady-state bending moment for a uniform bar, simply supported at both ends and subjected to a harmonically varying bending moment or deflection at one end. These quantities, together with those presented in a previous report (1) * , are intended to facilitate the determination of the steady-state response and of the natural modes of bending vibration of continuous beams and frames.Office of Naval Research. Department of the Navy.Contract N6ori-71(06), Task Order VI, Project NR-064-18