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Home > Publications > International Concrete Abstracts Portal
Showing 1-5 of 16 Abstracts search results
Document:
SP78-15
Date:
January 1, 1982
Author(s):
A. Rajaraman and C.V. Vaidyanathan
Publication:
Symposium Papers
Volume:
78
Abstract:
In the design of frames supporting machines inducing harmonic excitations, the frequency level is a major consideration. Altering this level - called tuning - requires the change in design parameters. This study presents results by introducing a new parameter - taper - so that existing frames could be tuned properly or in many cases redesigned to take up increased speeds of machinery. The results are given in tabular form for ready reference.
DOI:
10.14359/17527
SP78-10
Michael J. O'Rourke and Ricardo Dobry
This paper presents a simplified procedure for calculating the equivalent stiffness and clamping of a pile supported machine foundation. Separate procedures are developed for the case where there is a small gap between the bottom of the pile cap and the soil surface (Gap Case) as well as the case where there is continuous contact at all times between the bottom of the pile cap and the soil (No Gap Case). The horizontal and vertical spring constants are developed using beam on elastic foundation concepts. Both material and geometric damping contribute to the dashpot coefficients. The radiation or geometric dashpots are developed from wave propagation considerations. The equivalent springs and dashpots for individual piles in the Gap Case compare well with corresponding values obtained from a dynamic finite element program.
10.14359/16911
SP78-05
F. Aboul-Ella and M. Novak
A theoretical approach was developed and programmed to analyze dynamic response of turbomachinery frame foundations supported by piles or a foundation slab. The study investigates interaction of all components of the system, i.e. flexible rotors, visco-elastic oil film, space frame, flexible mat, piles and soil. The effect of the foundation on vibration amplitudes of the frame and rotors is demonstrated.
10.14359/16906
SP78-06
David Weiner and Benat B. Broms
The design and construction of foundations for gangsaws are discussed. Criteria are proposed to evaluate the risk of damaging machines and buildings based on extensive measurements in sawmills in Sweden where in some cases damage had occurred. The results of a questionnaire indicate that problelms due to vibrations from gangsaws are common particularly where the foundations are supported on piles and where the ground water level is high. The questionnaire also indicates that a large number of sawmill workers (up to 752) are troubled by vibrations and noise. Several case records are presented which indicate that the natural frequency of sawmill buildings is often very close to the operating frequency of the gangsaws they house, exacerbating problems due to vibration. Remedial measures are discussed in the article such as changing the mass of the counterweight, the operating frequency or the geometry or weight of the foundation block. In two practical cases that are discussed the use of the tuning technique minimised interruptions in operation and prevented breakdowns which would otherwise have caused considerable financial loss.
10.14359/16907
SP78-07
Richard Orr
This paper describes the development of the turbine-generator support for a Floating Nuclear Plant (FNP). It discusses some of the alternative configurations considered and describes the basis for the selection of a spring-mounted concrete table top. The paper covers the methodology and results of static and dynamic analyses performed to evaluate the behavior of the turbine generator on the spring-mounted concrete table top supported by the main deck of the steel platform.
10.14359/16908
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The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
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