Vibration Test Fixtures – A Reason For Concern

vibration test fixtures
vibration test fixtures

The Importance of  Vibration Test Fixtures

For most projects, the design of vibration test fixtures is often left to the last minute.  Regardless of your industry, vibration testing is one of the most important tools in product test and evaluation.  A well designed fixture will provide ample rigidity to prevent resonances that can result in product over test.  It will help provide confidence that the vibration encountered by the unit under test is representative of the required spectrum.

Using you own

Using your own vibration test fixture as opposed to using one from a test facility has many benefits.  Fixtures laying around test labs are often drilled out and adapted for any number or customers’ immediate requirements.  If retesting is required, having your own fixture assures you of a more repeatable test regardless of the test facility you may use.  The same fixtures can also be used for shock testing where rigidity and strength are requirements.  Using vibration test fixtures in environmental chamber tests for can facilitate proper orientation of equipment and prevent accidental damage to interconnected test items during removal from the chamber.

Designing your Fixture

Rigidity is the major consideration in vibration fixture design.  A microscopic deflection in any part of the fixture can result in alarming resonances and nulls.  Aluminum is an excellent material for vibration test fixtures as it provides the required rigidity while minimizing weight.  The US Government’s Department of Defense has substantial research available for US Companies to use for designing a vibration test fixture.

Consider the intended orientations of test items and provide mounting holes for test items so that they can be easily installed and removed.  Time goes by quickly in the lab.  Use through-bolt for mounting the test item as threads in the fixture will fatigue over time. Provide ample through holes for mounting the fixture to the test equipment, especially if you plan to conduct multi-axis (X,Y,Z) testing.

Validate your Fixture

Before using your vibration fixture in testing it is beneficial to perform a resonance scan  to check for any unwanted responses.  This is accomplished by attaching multiple accelerometers to the fixture, and sending low-level random signals that cover the frequency range of your intended test.

CVG Strategy Experts

Our experts at CVG Strategy have extensive experience in Environmental/Dynamic and EMI/EMC testing for a number of industries and products, both military and commercial.  CVG Strategy specializes in Independent Developmental Testing and Evaluation including development of Test Plans, Test Procedures, Test Witnessing and Troubleshooting.

CVG Strategy is a consultancy offering coaching, mentoring, training and program development focused on areas including Business Process Improvement, ITAR and Export Compliance, Cyber Security and Quality Management Systems.

Test Witnessing Adds Value to your Evaluation Program

Test Witnessing

The importance of Test Witnessing is often overlooked by many engineering teams.

Effective test witnessing of each individual product test or during a product test program is the best way to maximize the value returned on investment.  Testing can be expensive.  It is important to get maximum value for your company’s investment.

If a product fails during a test, how do you know if it was a true product failure or actually the result of an overtest or undertest condition at the test lab if you are not present?

Product testing for commercial or military products requires a considerable investment in time and money.  Getting the most out of product testing involves more than a report with a pass/fail status.

Test witnessing is often applied when a thorough independent evaluation of a product is required.  Proper test witnessing ensures that test procedures are performed as specified and that any deviations or anomalies are avoided and mitigated where possible.  When failures are encountered, extensive data recovery, determination of possible overtest, and troubleshooting possible causes of failure are invaluable, if you are onsite and able to take action.Test Witnessing

In the lab setting, time is a precious commodity.  Delays due to lack of preparedness, quirky UUT (Unit Under Test) operating issues and vague test procedures are common and can be addressed by having a test witness at the lab.  During the course of a test program sometimes quick decisions must be made to seek alternatives when lab equipment becomes unavailable.  Having a test witness work with lab personnel ensures that your product is tested to your documented requirements and performed on schedule.

Test witnessing requires an in-depth familiarity with standards, detailed knowledge of the required and appropriate test procedures, and an understanding of test lab protocols and dynamics.  It also requires extensive recordkeeping over and above that performed by lab personnel.  This is not limited to Environmental/Dynamic testing but also applies to EMI/EMC testing where experience in detecting anomalies in equipment operation during susceptibility testing is critical.  In this area the effective use of lab time in troubleshooting of emission testing failures for sources and possible solutions is also essential.

Product testing is a valuable tool to verify and validate a system or component’s ability to perform as required throughout its life cycle.  As such it should be witnessed by people experienced in the methodologies and strategies to guarantee optimal results.  CVG Strategy has expert test witness specialists available to help our customers through testing and evaluation programs.

CVG Strategy Experts

Our experts at CVG Strategy have extensive experience in Environmental/Dynamic and EMI/EMC testing for a number of industries and products, both military and commercial.  CVG Strategy specializes in Independent Developmental Testing and Evaluation including the development of Test Plans, Test Procedures, Test Witnessing, and Troubleshooting.

CVG Strategy is a consultancy offering coaching, mentoring, training and program development focused on areas including Business Process Improvement, ITAR and Export Compliance, Cyber Security and Quality Management Systems.

Susceptibility EMI/EMC Testing – Strategies

EMI EMC Susceptibility

EMI EMC Susceptibility testing is the first and most important test in any program.

There have been frequent examples of product failures due to EMI EMC susceptibility issues in the news of late.  Failures like these can result in property damage, loss of life, product recall, and huge fines.  Toyota and Honda have recently had incidents with unwanted vehicle acceleration and braking that may have been caused by EMI EMC susceptibility problems.  Pacemakers have been linked to EMI EMC susceptibility faults that can cause a number of undesired symptoms to patients. Medical and Automotive industries, of course, are not alone. Avionics, communications systems, and military systems all share the same concerns of EMI EMC susceptibility.

As we surround ourselves with electronic devices, the threat that systems we rely on are at risk of failing to an extent which is irreversible and potentially fatal should give pause to designers of these devices.

This inherent liability of manufacturing electronic products in today’s market increases the importance of EMI/EMC, and ESD testing.  The role of testing can no longer be limited to achieving compliance to governmental regulations or customer flow downs but must be an important part of Developmental and Operational Testing & Evaluation.

The development of an overall test strategy in the early stages of product development and an understanding of the tests to be performed will help to identify potential areas of concern soon enough to be avoided or solved before they can derail scheduling.

EMI-EMC SusceptibilityResources should also be allotted for development of off-chamber equipment to simulate peripheral components and appropriately engage the equipment under test in a manner that will reflect performance of the product in the field.  This simulation equipment can also aid in monitoring during susceptibility testing and troubleshooting during emissions testing where transient susceptibility events can be difficult to observe and capture.  EMI EMC susceptibility is a challenge for everyone.

CVG Strategy Experts

Our experts at CVG Strategy have extensive experience in Environmental/Dynamic and EMI/EMC testing for a number of industries and products, both military and commercial.  CVG Strategy specializes in Independent Developmental Testing and Evaluation including development of Test Plans, Test Procedures, Test Witnessing and Troubleshooting.

CVG Strategy is a consultancy offering coaching, mentoring, training and program development focused on areas including Business Process Improvement, ITAR and Export Compliance, Cyber Security and Quality Management Systems.

Product Test Standards and Specifications

product test standards

Using Product Test Standards to Develop a Test and Evaluation Program

There is a seemingly endless amount of product test standards and specifications.   These documents set criteria for compliance, provide guidance for evaluation, and sometimes assist in the development of analysis and test programs of both consumer products and military products.  They are all constantly evolving as new revisions are released periodically.

Not all Product Test Standards and Specifications are Equal

Some product test standards offer very clear and concise parameters for product evaluation.  Other test standards can be vague in the details of their requirements.  The quality of writing and organization can also greatly vary.  Many have annexes and appendices full of extremely in depth information that can clarify a test’s methodologies and intents.

product test standards

Each product test standard should be treated by the reader as unique as to its perspective and purpose.  MIL-STD-810H for example places a huge emphasis on tailoring parameters of test methods to reflect the environmental stresses the product to be tested will encounter throughout its life cycle.  This perspective is not as applicable to standards for compliance where strict parameters and procedures are required.This can present a challenge to managers of test programs,

especially those who are working with a product that is being released to new markets.  Allocating the time and resources to grasp the entirety of required test procedures can be daunting.  Test laboratories can provide guidance but it is beyond their scope to advocate management strategies to best establish programs fit for your product.  Test laboratories cannot give recommendations on product test standards and still remain an independent evaluating body.

Regular attendance of seminars can greatly aid in developing the required insights into a standards intricacies.  Engaging a competent third party to develop product test and evaluation programs would be of great value when entering into new markets, especially if a company is transitioning from commercial to military applications.

CVG Strategy Experts

Our experts at CVG Strategy have extensive experience in Environmental/Dynamic and EMI/EMC testing for a number of industries and products, both military and commercial.  CVG Strategy specializes in Independent Developmental Testing and Evaluation including development of Test Plans, Test Procedures, Test Witnessing and Troubleshooting.

CVG Strategy is a consultancy offering coaching, mentoring, training and program development focused on areas including Business Process Improvement, ITAR and Export Compliance, Cyber Security and Quality Management Systems

EDC Volunteer of the Year Award 2010 Kevin Gholston

Community

Florida’s Space Coast EDC Volunteer of the Year Award 2010 – Kevin M. Gholston

In August 2006, Kevin Gholston joined the Economic Development Commission of Florida’s Space Coast as an investor.  His first assignment was to chair the Industry Advisory Council leading its initiative to reach Brevard Public Schools High School Children to educate them on careers in manufacturing.  In 2009 he transferred to Chair the Ad Valorem Tax Abatement Council. 

During his tenure, the committee has reviewed over 50 applications for expansion or relocation, fulfilling the State of Florida statutory requirement as the citizen board to review and recommend to the Brevard County Commission.

The Brevard County Commision was reviewing its relationship with the EDC in the spring of 2010, and Kevin assisted the effort to show the business community support for the EDC.  This is when he gave his “Pennies” Speech to the Commissioners, and a portion of this speech is shown in the attached video.  It was all about a mason jar of pennies and the total number of pennies: 268 ($2.68). 

Kevin explained that this was what each citizen’s contribution was through the Brevard County Commission annually.  He believe it was worth it and should be continued.  Kevin Gholston received the EDC Volunteer of the Year Award 2010 for the Economic Development Commission of Florida’s Space Coast in 2010 for his dedication and hard work supporting economic development in Brevard County, Florida.

Kevin is Vice President of CVG Strategy, a consultancy that helps local businesses reach their potential.  They provide expertise in Quality Management Systems, Product Test and Evaluation, Export Compliance, and Cybersecurity.  Kevin has been instrumental in bringing his skills to work by consistently adding value to his customers.  This dedication to excellence has been the trademark of companies he has worked with in Florida and beyond.

EDC Volunteer of the Year Award