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Vibration and Shock

Test Control Techniques

 

Program Duration

:

5 Days

Program Date

:

07-11 April, 2012

Program Location

:

Cairo, Egypt

Program Fees

:

US$ 3200/Per Person

 

WHO SHOULD ATTEND?

Engineering or technical personnel involved in specifying, tailoring (e.g. MIL-STD-810E) and performing state-of-the-art random vibration and shock tests; those who obtain/analyze/review field and laboratory test data; and those who design/certify hardware/structures/instrumentation to meet dynamic environmental requirements. Members of the automotive, aerospace, aircraft, shipboard and weapons technical

 

PROGRAM OBJECTIVES:

 Brief Course Description The objective of the first portion of the course (also available separately as curce is to provide participants with the knowledge required to specify, evaluate and use a wide variety of digital data acquisition systems in laboratory and field applications. Basic principles of sampling and digitizing theory are presented and reinforced with practical examples from everyday testing operations. Emphasis is placed on understanding the theoretical concepts through “mechanical feel” rather than mathematics.

 

Hardware discussions concentrate on performance capabilities and practical problems that arise in laboratory and field applications.

 Heavy emphasis is placed on new technologies and system concepts that will be available in the near future. The aim is to prepare participants to design and procure state-of-the art systems that will satisfy their technical requirements efficiently and economically.

Literature describing the latest available hardware will be used as examples of good (and bad) practice. Particular emphasis will be placed on critical evaluation of commercially-available hardware and software systems.

 

The second portion of the course is an overview of vibration-testing technology with emphasis on the practical everyday problems that are encountered in testing laboratories. Emphasis is placed on the basic principles of vibration hardware, control systems, and analysis techniques used for random, sine, and shock testing. Capabilities and limitations of available systems will be discussed.

This course presents an application-oriented approach to digital computer control of random vibration and shock testing on shakers and analysis of vibration and shock data. Complex mathematical concepts are reduced to graphic form for intuitive understanding. Illustrative examples from the “real world” are used throughout. Demonstration programs written in LabView are used during the course to illustrate the concepts. These demonstrations are Students are encouraged to download the demonstration programs prior to class, and install them on a laptop computer they can bring with them to class and use to follow along with the instructor when the demonstrations are presented.

 

The course is presented as a series of highly-interactive lecture/discussion sessions. Problems for individual and group solution are interspersed throughout the course to act as training aids and to evaluate class progress. Special-interest discussions are encouraged outside of the regular course sessions.

 

PROGRAM OUTLINES:

  

Overview of the Measurement Process — The System Approach

  • The role and function of digital data acquisition.

  • Testing and experiment types — what capabilities are required?

  • Accuracy, Dynamic Range, Headroom

    • Basic Concepts

    • Basic calculations

  • The Fourier Transform as a “Black Box”

  • Data presentation in time and spectral domain

Sampling and Digitization Theory

  • Data acquisition speed and accuracy/resolution considerations

  • Noise and other data corruption problems

Data Acquisition Hardware

  • Signal Conditioning

  • Amplifiers

    • Common-mode rejection

    • Transducer wiring practice

  • Anti-alias filters

    •   Estimating aliasing errors for different filter types

    •   Filter/Sample-rate tradeoffs

  • Sample-and-hold amplifiers

  • Multiplexers

  • Analog-to-digital converters

    •   Flash, Successive-approximation, Multi-pass, Sigma-Delta, Integrating

The Computer System

  • Candidate computer systems — tradeoffs

  • Interface concepts — speed, implementation ease and robustness

  • Data storage — speed, volume considerations

Types of Digital Acquisition Systems

  • Applications, Special considerations, Performance and limitations of available system architectures

Data Analysis

  • Engineering-Unit Conversions

  •  Data Interpolation

  •  Correction of Anti-Alias filter distortion

Evaluating Data Acquisition Systems

  •        Simple tests to evaluate system accuracy/capability

Specifying a system

  •        How do you specify a system to get what you want?

  • Part II, Vibration and Shock Test Control Techniques

Introduction and Basic Concepts

Structural Resonances, Time History and Spectral Analysis

Test Objectives and Philosophy

  • Damage Potential

  • MIL-STD Testing

Environmental Simulation Concepts

  • Sine, Random, and Simulated Shock Excitation

  • Vibration and Shock History Reproduction

  • Test Specification

Simulation Methods

  • “Programmed” Excitation

    • Excitation Hardware

    •  Electrodynamics and Electrohydraulic Shakers

    •  Specifications and Real-World Behavior

    •  Excitation Functions

    • Impact” and “Drop” Machines

      Fixtures

Simulation “Accuracy” using different approaches

Measurement Systems

  • Transducers for Vibration and Shock

Data Acquisition Requirements and Methods

Analysis Tools

  • Averaging Concepts, Degrees of Freedom

  • Power Spectral Density (PSD) and Shock Response Spectrum (SRS)

Control Systems

  • Closed-Loop Control Concepts

    • Random Control

    • Spectral Control

    •  Response and Force Limiting

    •  Sine Controllers

    • Shock Synthesis and Control

Real-World Systems

  •  System Demonstration — videos

  • System/Physical/Method Limitations

  • What do the Control Parameters Mean?

  • How do they effect the results?

Multiple-Degree-of-Freedom Systems

  • Hardware Implementation

  • Control Strategies

Random Vibration for HALT, HASS and ESS applications

Review of currently available hardware

Real-World Test Laboratory Applications

Final Wrap-up

  • Student Topic/Problem Discussion

  • Review and Final Examination

  • Award of Certificate for Successful Completion