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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


Document: 

SP78-02

Date: 

January 1, 1982

Author(s):

Donald E. Baxa and Robert Ebisch

Publication:

Symposium Papers

Volume:

78

Abstract:

This paper is a case study of pneuniatic isolation systeliis in large automobile recycling machines. Machines of increasing size and power, plus a public that is increasingly insistent on its right to an environment free of noise and vibration, equal potential problenis for recycling plants. In response to this situation, a hammermill/shredder operation making successful use of pneunlatic isolation has been designed and constructed. The first, and still the largest, operation of its kind, the operation has demonstrated a valuable method of containing machine vibrations that might otherwise ignite hostility in the surrounding community and quite possibly bring on expensive legal action. The particular system described was installed in a 4,000-horsepower hammermill at an Indiana recycling firm. Besides effecting a more than 90 percent reduction in ground vibration, the system allows for easier and more efficient machine leveling and includes systems to warn of and localize pressure loss, to minimize routine mechanical shock, and to contain extraordinary shocks resulting from exploding gas tanks and loss of hammers within the machine. The system has now been in use for two years with no reported problems.

DOI:

10.14359/16903


Document: 

SP78-08

Date: 

January 1, 1982

Author(s):

P. Srinivasulu and N. Lakshmanan

Publication:

Symposium Papers

Volume:

78

Abstract:

In the first part, the paper critically reviews the current state of art on the analysis and design of typical types of machine foundations. The uncertainties in the design data and paucity of essential information required for a rational design are highlighted. The need to study the geotechnical features and other environmental factors at the proposed site of a machine foundation is emphasized. The various aspects of the problem of a machine foundation are illustrated with the explanation of five typical case studies selected from authors' experience in this line of work. The paper also underlines the need for a close co-ordination between the civil and mechanical engineers responsible for the installation of machine foundation right from the early stages of planning.

DOI:

10.14359/16909


Document: 

SP78-07

Date: 

January 1, 1982

Author(s):

Richard Orr

Publication:

Symposium Papers

Volume:

78

Abstract:

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.

DOI:

10.14359/16908


Document: 

SP78-06

Date: 

January 1, 1982

Author(s):

David Weiner and Benat B. Broms

Publication:

Symposium Papers

Volume:

78

Abstract:

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.

DOI:

10.14359/16907


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