36 research outputs found
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
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 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
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