Зарегистрироваться
Восстановить пароль
FAQ по входу

Lalanne C. Mechanical Vibration and Shock Analysis. Specification Development (Volume 5)

  • Файл формата pdf
  • размером 9,50 МБ
  • Добавлен пользователем
  • Отредактирован
Lalanne C. Mechanical Vibration and Shock Analysis. Specification Development (Volume 5)
2nd Edition. — ISTE Ltd John Wiley & Sons, Inc., 2009. — 501 p. — ISBN: 978-1-84821-121-6 (Set of 5 Volumes), ISBN: 978-1-84821-126-1 (Volume 5).
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 the equipment which will be subject to these types of stresses is then detailed. The analysis takes account of 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. 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.
Table of Contents
Foreword to Series
Introduction
List of Symbols
Extreme Response Spectrum of a Sinusoidal Vibration
The effects of vibration
Extreme response spectrum of a sinusoidal vibration
Definition
Case of a single sinusoid
Case of a periodic signal
General case
Extreme response spectrum of a swept sine vibration
Sinusoid of constant amplitude throughout the sweeping process
Swept sine composed of several constant levels
Extreme Response Spectrum of a Random Vibration
Unspecified vibratory signal
Gaussian stationary random signal
Calculation from peak distribution
Use of the largest peak distribution law
Response spectrum defined by k times the rms response
Other ERS calculation methods
Limit of the ERS at the high frequencies
Response spectrum with up-crossing risk
Complete expression
Approximate relation
Calculation in a hypothesis of independence of threshold overshoot
Use of URS
Comparison of the various formulae
Effects of peak truncation on the acceleration time history
Extreme response spectra calculated from the time history signal
Extreme response spectra calculated from the power spectral densities
Comparison of extreme response spectra calculated from time history signals and power spectral densities
Sinusoidal vibration superimposed on a broad band random vibration
Real environment
Case of a single sinusoid superimposed to a wide band noise
Case of several sinusoidal lines superimposed on a broad band random vibration
Swept sine superimposed on a broad band random vibration
Real environment
Case of a single swept sine superimposed to a wide band noise
Case of several swept sines superimposed on a broad band random vibration
Swept narrow bands on a wide band random vibration
Real environment
Extreme response spectrum
Fatigue Damage Spectrum of a Sinusoidal Vibration
Fatigue damage spectrum definition
Fatigue damage spectrum of a single sinusoid
Fatigue damage spectrum of a periodic signal
General expression for the damage
Fatigue damage with other assumptions on the S–N curve
Taking account of fatigue limit
Cases where the S–N curve is approximated by a straight line in log–lin scales
Comparison of the damage when the S–N curves are linear in either log–log or log–lin scales
Fatigue damage generated by a swept sine vibration on a single-degree-of-freedom linear system
General case
Linear sweep
Logarithmic sweep
Hyperbolic sweep
General expressions for fatigue damage
Reduction of test time
Fatigue damage equivalence in the case of a linear system
Method based on fatigue damage equivalence according to Basquin’s relationship
Notes on the design assumptions of the ERS and FDS
Fatigue Damage Spectrum of a Random Vibration
Fatigue damage spectrum from the signal as function of time
Fatigue damage spectrum derived from a power spectral density
Simplified hypothesis of Rayleigh’s law
Calculation of the fatigue damage spectrum with Dirlik’s probability density
Reduction of test time
Fatigue damage equivalence in the case of a linear system
Method based on a fatigue damage equivalence according to Basquin’s relationship taking account of variation of natural damping as a function of stress level
Truncation of the peaks of the input acceleration signal
Fatigue damage spectra calculated from a signal as a function of time
Fatigue damage spectra calculated from power spectral densities
Comparison of fatigue damage spectra calculated from signals as a function of time and power spectral densities
Sinusoidal vibration superimposed on a broad band random vibration
Case of a single sinusoidal vibration superimposed on broad band random vibration
Case of several sinusoidal vibrations superimposed on a broad band random vibration
Swept sine superimposed on a broad band random vibration
Case of one swept sine superimposed on a broad band random vibration
Case of several swept sines superimposed on a broad band random vibration
Swept narrow bands on a broad band random vibration
Fatigue Damage Spectrum of a Shock
General relationship of fatigue damage
Use of shock response spectrum in the impulse zone
Damage created by simple shocks in static zone of the response spectrum
Influence of Calculation: Conditions of ERSs and FDSs
Variation of the ERS with amplitude and vibration duration
Variation of the FDS with amplitude and duration of vibration
Should ERSs and FDSs be drawn with a linear or logarithmic frequency step?
With how many points must ERSs and FDSs be calculated?
Difference between ERSs and FDSs calculated from a vibratory signal according to time and from its PSD
Influence of the number of PSD calculation points on ERS and FDS
Influence of the PSD statistical error on ERS and FDS
Influence of the sampling frequency during ERS and FDS calculation from a signal based on time
Influence of the peak counting method
Influence of a non-zero mean stress on FDS
Tests and Standards
Definitions
Standard
Specification
Types of tests
Characterization test
Identification test
Evaluation test
Final adjustment/development test
Prototype test
Pre-qualification (or evaluation) test
Qualification
Qualification test
Certification
Certification test
Stress screening test
Acceptance or reception
Reception test
Qualification/acceptance test
Series test
Sampling test
Reliability test
What can be expected from a test specification?
Specification types
Specification requiring in situ testing
Specifications derived from standards
Current trend
Specifications based on real environment data
Standards specifying test tailoring
The MIL–STD 810 standard
The GAM.EG 13 standard
STANAG
The AFNOR X50–410 standard
Uncertainty Factor
Need – definitions
Sources of uncertainty
Statistical aspect of the real environment and of material strength
Real environment
Material strength
Statistical uncertainty factor
Definitions
Calculation of uncertainty factor
Calculation of an uncertainty coefficient when the real environment is only characterized by a single value
Aging Factor
Purpose of the aging factor
Aging functions used in reliability
Method for calculating aging factor
Influence of standard deviation of the aging law
Influence of the aging law mean
Test Factor
Philosophy
Calculation of test factor
Normal distributions
Log–normal distributions
Weibull distributions
Choice of confidence level
Influence of the number of tests n
Specification Development
Test tailoring
Step 1: analysis of the life cycle profile. Review of the situations
Step 2: determination of the real environmental data associated with each situation
Step 3: determination of the environment to be simulated
Need
Synopsis methods
The need for a reliable method
Synopsis method using power spectrum density envelope
Equivalence method of extreme response and fatigue damage
Synopsis of the real environment associated with an event (or sub-situation)
Synopsis of a situation
Synopsis of all life profile situations
Search for a random vibration of equal severity
Validation of duration reduction
Step 4: establishment of the test program
Application of a test factor
Choice of the test chronology
Applying this method to the example of the round robin comparative study
Taking environment into account in project management
Influence of Calculation: Conditions of Specification
Choice of the number of points in the specification (PSD)
Influence of Q factor on specification (outside of time reduction)
Influence of Q factor on specification when duration is reduced
Validity of a specification established for Q factor equal to 10 when the real structure has another value
Advantage in the consideration of a variable Q factor for the calculation of ERSs and FDSs
Influence of the value of parameter b on the specification
Case where test duration is equal to real environment duration
Case where duration is reduced
Choice of the value of parameter b in the case of material made up of several components
Influence of temperature on parameter b and constant C
Importance of a factor of 10 between the specification FDS and the reference FDS (real environment) in a small frequency band
Validity of a specification established by reference to a 1-dof system when real structures are multi-dof systems
Other Uses of Extreme Response, Up-Crossing Risk and Fatigue Damage Spectra
Comparisons of the severity of different vibrations
Comparisons of the relative severity of several real environments
Comparison of the severity of two standards
Comparison of earthquake severity
Swept sine excitation – random vibration transformation
Definition of a random vibration with the same severity as a series of shocks
Writing a specification only from an ERS (or a URS)
Matrix inversion method
Method by iteration
Establishment of a swept sine vibration specification
Appendices
Formulae
Bibliography
Index
Summary of Other Volumes in the Series
  • Чтобы скачать этот файл зарегистрируйтесь и/или войдите на сайт используя форму сверху.
  • Регистрация