Author:
Publisher:
ISBN:
Category : Shock
Languages : en
Pages : 0
Book Description
Many items of equipment in a variety of vehicles are subjected to both shock and short (nonstationary) bursts of random excitation. It is common practice to analyze these latter events as though they were stationary and measure their severity in terms of spectral density of acceleration. The errors involved and difficulties of doing this are reviewed. Actually, short bursts of random vibration are similar to random shocks, particularly when the failure, if any, is due to the single highest peak (SHP) of the response, rather than to fatigue. The importance of the SHP as a measure of damage is also discussed. When it is the correct damage criterion, we should attempt to control it and not spectral density. Since the SHP is a random variable, we cannot control it using random excitation, but we can with shock tests. For systems with a single degree of freedom, or those whose sensitivity to damage is known to be confined to a narrow frequency band, the solution is simple, once the statistical distribution of the SHP is known. Available experimental and theoretical data are reviewed. Using the prescribed percentile of the SHP distribution, the shock test as severe as the random excitation is derived. In certain cases, when both stationary random and shock tests are prescribed, the former can be eliminated by deriving a shock test whose highest response peaks at each frequency envelop those of both original tests. The Situation with multidegree of freedom systems is shown to be significantly more difficult and not amenable to one method of solution. A technique is introduced for extending the results to these situations. Preliminary results obtained on a analog computer for the two degree of freedom system are presented to illustrate certain trends.
The Shock and Vibration Bulletin. Bulletin 35 Part 6 of 7
Author:
Publisher:
ISBN:
Category : Shock
Languages : en
Pages : 0
Book Description
Many items of equipment in a variety of vehicles are subjected to both shock and short (nonstationary) bursts of random excitation. It is common practice to analyze these latter events as though they were stationary and measure their severity in terms of spectral density of acceleration. The errors involved and difficulties of doing this are reviewed. Actually, short bursts of random vibration are similar to random shocks, particularly when the failure, if any, is due to the single highest peak (SHP) of the response, rather than to fatigue. The importance of the SHP as a measure of damage is also discussed. When it is the correct damage criterion, we should attempt to control it and not spectral density. Since the SHP is a random variable, we cannot control it using random excitation, but we can with shock tests. For systems with a single degree of freedom, or those whose sensitivity to damage is known to be confined to a narrow frequency band, the solution is simple, once the statistical distribution of the SHP is known. Available experimental and theoretical data are reviewed. Using the prescribed percentile of the SHP distribution, the shock test as severe as the random excitation is derived. In certain cases, when both stationary random and shock tests are prescribed, the former can be eliminated by deriving a shock test whose highest response peaks at each frequency envelop those of both original tests. The Situation with multidegree of freedom systems is shown to be significantly more difficult and not amenable to one method of solution. A technique is introduced for extending the results to these situations. Preliminary results obtained on a analog computer for the two degree of freedom system are presented to illustrate certain trends.
Publisher:
ISBN:
Category : Shock
Languages : en
Pages : 0
Book Description
Many items of equipment in a variety of vehicles are subjected to both shock and short (nonstationary) bursts of random excitation. It is common practice to analyze these latter events as though they were stationary and measure their severity in terms of spectral density of acceleration. The errors involved and difficulties of doing this are reviewed. Actually, short bursts of random vibration are similar to random shocks, particularly when the failure, if any, is due to the single highest peak (SHP) of the response, rather than to fatigue. The importance of the SHP as a measure of damage is also discussed. When it is the correct damage criterion, we should attempt to control it and not spectral density. Since the SHP is a random variable, we cannot control it using random excitation, but we can with shock tests. For systems with a single degree of freedom, or those whose sensitivity to damage is known to be confined to a narrow frequency band, the solution is simple, once the statistical distribution of the SHP is known. Available experimental and theoretical data are reviewed. Using the prescribed percentile of the SHP distribution, the shock test as severe as the random excitation is derived. In certain cases, when both stationary random and shock tests are prescribed, the former can be eliminated by deriving a shock test whose highest response peaks at each frequency envelop those of both original tests. The Situation with multidegree of freedom systems is shown to be significantly more difficult and not amenable to one method of solution. A technique is introduced for extending the results to these situations. Preliminary results obtained on a analog computer for the two degree of freedom system are presented to illustrate certain trends.
The Shock and Vibration Bulletin
Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 100
Book Description
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 100
Book Description
Technical Abstract Bulletin
Mechanical Vibration and Shock Analysis, Mechanical Shock
Author: Christian Lalanne
Publisher: John Wiley & Sons
ISBN: 1118618912
Category : Technology & Engineering
Languages : en
Pages : 326
Book Description
Mechanical Vibration and Shock Analysis, Second Edition Volume 2: Mechanical Shock This volume considers the shock response spectrum, its various definitions, its properties, and the assumptions involved in its calculation. In developing the practical application of these concepts, the shock shapes or profiles most often used in test facilities are presented, together with their characteristics and indications of how to establish test configurations comparable with those of the real-world, measured environment. Following this analysis there is a case study of how to meet these specifications using standard laboratory equipment, shock machines, electrodynamic exciters driven by a time signal or a response spectrum. Discussion of the limitations, advantages and disadvantages of each method is presented. The Mechanical Vibration and Shock Analysis five-volume series has been written with both the professional engineer and the academic in mind. Christian Lalanne explores every aspect of vibration and shock, two fundamental and extremely significant areas of mechanical engineering, from both a theoretical and practical point of view. The five volumes cover all the necessary issues in this area of mechanical engineering. The theoretical analyses are placed in the context of both the real world and the laboratory, which is essential for the development of specifications.
Publisher: John Wiley & Sons
ISBN: 1118618912
Category : Technology & Engineering
Languages : en
Pages : 326
Book Description
Mechanical Vibration and Shock Analysis, Second Edition Volume 2: Mechanical Shock This volume considers the shock response spectrum, its various definitions, its properties, and the assumptions involved in its calculation. In developing the practical application of these concepts, the shock shapes or profiles most often used in test facilities are presented, together with their characteristics and indications of how to establish test configurations comparable with those of the real-world, measured environment. Following this analysis there is a case study of how to meet these specifications using standard laboratory equipment, shock machines, electrodynamic exciters driven by a time signal or a response spectrum. Discussion of the limitations, advantages and disadvantages of each method is presented. The Mechanical Vibration and Shock Analysis five-volume series has been written with both the professional engineer and the academic in mind. Christian Lalanne explores every aspect of vibration and shock, two fundamental and extremely significant areas of mechanical engineering, from both a theoretical and practical point of view. The five volumes cover all the necessary issues in this area of mechanical engineering. The theoretical analyses are placed in the context of both the real world and the laboratory, which is essential for the development of specifications.
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 248
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 248
Book Description
Mechanical Vibration and Shock Analysis, Specification Development
Author: Christian Lalanne
Publisher: John Wiley & Sons
ISBN: 1848216483
Category : Science
Languages : en
Pages : 546
Book Description
Everything engineers need to know about mechanical vibration and shock...in one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to maintain structural integrity in the event of a crash. There are detailed examinations of underlying theory, models developed for specific applications, performance of materials under test conditions and in real-world settings, and case studies and discussions of how the relationships between these affect design for actual products. Invaluable to engineers specializing in mechanical, aeronautical, civil, electrical and transportation engineering, this reference work, in five volumes is a crucial resource for the solution of shock and vibration problems. This volume focuses on specification development in accordance with the principle of tailoring. Extreme response and the fatigue damage spectra are defined for each type of stress (sinusoidal vibration, swept sine, shock, random vibration, etc.). The process for establishing a specification from the life cycle profile of equipment which will be subject to these types of stresses is then detailed. The analysis takes into account the uncertainty factor, designed to cover uncertainties related to the real-world environment and mechanical strength, and the test factor, which takes account of the number of tests performed to demonstrate the resistance of the equipment.
Publisher: John Wiley & Sons
ISBN: 1848216483
Category : Science
Languages : en
Pages : 546
Book Description
Everything engineers need to know about mechanical vibration and shock...in one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to maintain structural integrity in the event of a crash. There are detailed examinations of underlying theory, models developed for specific applications, performance of materials under test conditions and in real-world settings, and case studies and discussions of how the relationships between these affect design for actual products. Invaluable to engineers specializing in mechanical, aeronautical, civil, electrical and transportation engineering, this reference work, in five volumes is a crucial resource for the solution of shock and vibration problems. This volume focuses on specification development in accordance with the principle of tailoring. Extreme response and the fatigue damage spectra are defined for each type of stress (sinusoidal vibration, swept sine, shock, random vibration, etc.). The process for establishing a specification from the life cycle profile of equipment which will be subject to these types of stresses is then detailed. The analysis takes into account the uncertainty factor, designed to cover uncertainties related to the real-world environment and mechanical strength, and the test factor, which takes account of the number of tests performed to demonstrate the resistance of the equipment.
U.S. Government Research & Development Reports
Engineering Design Handbook, Environmental Series
Author: United States. Army Materiel Command
Publisher:
ISBN:
Category : Environmental engineering
Languages : en
Pages : 410
Book Description
Publisher:
ISBN:
Category : Environmental engineering
Languages : en
Pages : 410
Book Description
The Shock and Vibration Bulletin
Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 882
Book Description
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 882
Book Description
The Journal of Environmental Sciences
Author:
Publisher:
ISBN:
Category : Environmental engineering
Languages : en
Pages : 860
Book Description
Publisher:
ISBN:
Category : Environmental engineering
Languages : en
Pages : 860
Book Description