Training in Fundamentals of Random Vibration and Shock Testing
DATE: January 5-7, 2021 8am – 4pm PST
WEBINAR Live, on-line broadcast
in collaboration with WESTPAK, Inc.
TEACHER: Steve Brenner
CONTACT: (805) 456-4274
This three-day Fundamentals of Vibration and Shock training WEBINAR covers all the information required to plan, perform and interpret the results of all types of dynamic testing. Some of the additional areas covered are fixture design, field data measurement and interpretation, evolution of test standards and HALT/HASS processes.
This class is applicable to ANY vibration and shock testing done to environmental test standards including MIL-STD-810, DO-160, IEC specifications, and all other documents which provide test methodology for environmental testing. The test methods explained and taught in this class apply to testing of ANY equipment subjected to dynamic environments whether it is intended for military/aerospace, commercial, or consumer use.
We overview Sine and Random Vibration, also classical waveform shock testing, drop testing and Shock Response Spectrum Testing. We include instrumentation, vibration test, equipment, control systems and fixture design and evaluation.
In addition to numerous photographs and videos the class will watch a pre-recorded lab visit which will include a demonstration of the vibration test equipment and test techniques discussed in class. An instrumented resonant structure is excited first with slowly sweeping constant acceleration sine vibration. As the frequency increases the observers will directly see the decrease in displacement. The sine vibration demonstration will be followed by an all-frequencies-simultaneous random vibration. Responses will be are compared.
Classroom discussion is supported by projected visuals and video clips. Commencing with a review of basic vibrations, we will explore vibration measurements and analysis. We will compare sinusoidal vs. random vibration testing systems, specifications, standards and procedures. We will emphasize vibration and shock test fixture design, fabrication, experimental evaluation, and usage. We will study shock measurement, shock response spectrum (SRS) and shock testing.
The webinar is completely interactive. Students will have the opportunity to ask questions and request clarification throughout the class time.
The course emphasizes topics you will use immediately. Suppliers to the military services protectively install commercial-off-the-shelf (COTS) equipment in our flight and land vehicles and in shipboard locations where vibration and shock can be severe. We laboratory test the protected equipment (1) to assure maximum equipment survival and possible combat, also (2) to meet commercial test standards, IEC documents, military standards such as STANAG or MIL-STD-810H, DO-160, etc. Few if any engineering schools teach about such protection or such testing. Hence this specialized course.
After this short course, you will be able to
- measure vibration and shock,
- calibrate vibration and shock measurement systems,
- convert field measured data into a test program,
- interpret vibration and shock test requirements,
- supervise vibration and shock tests,
- specify and successfully purchase test equipment to perform vibration and shock tests,
- specify, design, and experimentally evaluate vibration and shock test fixtures,
- specify and perform ESS, HALT and HASS.
When you visit a lab or review a test program, you will have a good understanding of the requirements and execution of dynamics tests and will be able to ask meaningful questions and understand lab peoples’ responses.
- I need practical knowledge about mechanical vibration and mechanical shock test, measurement, analysis, designing for dynamics also calibration and/or control because:
- I instrument land, sea and air vehicles as well as fixed-based equipment, in order to measure mechanical vibration and/or shock in service and during transport.
- I analyze dynamic responses to mechanical vibration and shock inputs during normal and abnormal transport.
- My title may be mechanical engineer, mechanical designer or packaging engineer. I design (ruggedize) products that must withstand factory handling + transport + normal and abnormal usage. I design products to dynamic requirements, which I don’t fully understand. Then I send a prototype to our lab for testing. I really don’t understand what our lab does. I’d better find out.
- I write contracts for procuring high-reliability equipment. I need to understand HALT, ESS and HASS. When do these acronyms apply? How do I insure that potential contractors will appropriately implement the random vibration requirements of these acronyms? What is g2/Hz?
- I work in an environmental test lab. We perform vibration and shock tests on prototype hardware. These tests may be part of developing a new product, of determining vibration levels for future production ESS (environmental stress screening) or production tests, or of investigating in-service or transport failures.
- I calibrate various vibration and shock sensors (including accelerometers) and analyze vibration and/or shock.
- I design to control (reduce, protect) the intensity of vibration and/or shock, which otherwise may damage delicate equipment.
- I maintain machinery whose vibration signature can warn of approaching failure.
If you thought, “aha – that’s what I’m supposed to do” to any of the job descriptions listed above, then this course is intended for you. It will help you move up your own “learning curve.” A smaller group, for whom the instructor also intends this course: supervisors of any of the above listed activities. Perhaps you were thrust into this responsibility without adequate training. Maybe your predecessor had no opportunity to alert you to potential difficulties. You certainly need to know what your people are talking about. Possibly you had no formal training for your present responsibilities. You need to explain your department’s activities to your superiors in the technically correct language. Perhaps you need to decide between “in house” and “outside” testing.
Introduction for management and participants
- Purpose of environmental testing, particularly vibration and shock
- Purpose of environmental stress screening (ESS), nowadays HALT & HASS
- Types of vibration tests: resonance search/dwell, fatigue, specification
Discussion of attendees prior knowledge – Classical sinusoidal vibration never observed in service; useful concept
- Introduction: terminology, structural resonant behavior, passive and active isolation
- Sinusoidal vibration measurements: units, sensors, readouts, errors
- Calibration of sensors and systems; traceability to NIST
Introduction to spectrum analysis Sinusoidal vibration testing
- Electrohydraulic and electrodynamic shakers; theory, tradeoffs, limits
- Power amplifier theory, operation, limitations, distortion effects
- Controls for sinusoidal vibration testing
- Sinusoidal vibration test practice
- Interpretation of standards; e.g. MIL-STD-810, DO-160, etc.
- Controversial test methodology: tracking filters, switching and averaging among sensors
Introduction to random vibration
- Sources of random vibration in service and transportation
- No possible equivalence to sinusoidal vibration
- Terminology and definitions
- Spectral density measurement and analysis – the frequency domain. What is g2/Hz?
- Probability density – the time domain
Random vibration test practice
- Interpreting and implementing standards, e.g. MIL-STD-810
- Equalization before testing; methods and limits
- Electronic protection for test items and shaker system
- Simultaneous multaxis vibration testing fixed spelling
- Intense acoustic noise testing
Combined environment (CERT) testing; reliability tests, e.g.MIL-STD-781 Environmental stress screening (ESS) of electronics hardware production
- Development of ESS techniques into the 21st century
Highly accelerated life testing (HALT), environmental stress screening (ESS) and highly accelerated stress screening (HASS) of electronics hardware production.
- Single vs. multi-axis vibration.
- Pneumatic repetitive-shock (RS) machines.
- Acoustic excitation of printed wiring boards (PWB).
Vibration and shock test fixtures; fixtures for stress screening
- Recommended designs, materials, fabrication methods
- Experimental evaluation before use
- Practical limits: transverse motion; specimen size and weight
- Where to put the control accelerometer, and why
Accommodating oversized loads
- Table expanders
- Slip plates and alternatives
Instrumentation for measuring shock in service and during tests
- Sensors, readouts, errors
Shock spectrum analysis; shock response spectrum
Shock testing standards and methods
Witnessing of tests
Course summary; optional final examination; award of certificates
To contact Steve send an email to firstname.lastname@example.org
Steve Brenner has been working in the field of environmental simulation and reliability testing for over 35 years. Commencing about 20 years ago, he became an independent consultant, and is one of ERI’s most sought-after teachers of short courses.
Beginning in the late sixties with reliability and design verification testing on the Lunar Module, the Space Shuttle in the eighties, to semiconductor manufacturing equipment in the nineties, Mr. Brenner has always been involved with the latest techniques for verifying equipment integrity through testing.
Mr. Brenner began his career as an Environmental test engineer with Grumman Aerospace Corporation in New York, worked as design verification and reliability engineer for the Air Force, an Environmental Test Engineer for Lockheed Missiles and Space company, and spent 18 years with Kaiser Electronics in San Jose, where he managed the Environmental Test Lab and was involved with the design of hardware intended for severe environments.
Mr. Brenner has been working as a consultant in the reliability testing field since 1996. His client base includes American and European companies with products:
- Automated test equipment
- Airborne displays
- Network equipment
- Medical equipment
- Semiconductor manufacturing equipment
- Aircraft instrumentation
- Ruggedized commercial electronic products (COTS)
- Fiber Optics components and systems
- Theme Park Rides
Mr. Brenner’s experience includes the entire range of climatic and dynamic testing, including HALT, HASS and long term reliability testing. He teaches several ERI courses each year, USA and abroad. In 2006 he and Wayne Tustin co-authored “Where to place the vibration test control accelerometer?”, which is available upon request.
Equipment Reliability Institute (ERI) offers specialized technical short course training in Shock and Vibration Testing, Climatics Testing and MIL-STD-810 Testing. Testing classes are applicable to all commercial, military and aerospace requirements.
Military Standard 810 (MIL-STD 810) @NTS Chicago March 27-30, 2023
Fundamentals of Random Vibration and Shock Testing @NTS Silicon Valley, CA November 7-9, 2023