Vibration Testing for military compliance is a crucial aspect for products aiming to serve in military applications. To ensure that these products can endure a severe military environment, they must undergo rigorous testing at a state-of-the-art vibration testing lab. This process involves defining the environmental life cycle that the product will encounter and then developing and executing a qualification test plan based on specific military standards. Completing these tests and documenting them in a detailed report is integral to achieving military compliance.

Why Perform Military Compliance Vibration Testing?

Military compliance vibration testing is especially crucial for military products integrated into complex and costly systems, where failure can lead to significant consequences. The principle reasons for executing this testing include the following:

1. Ruggedizing Your Product:  Testing your product to a military standard vibration profile will ensure that it can withstand harsh vibration exposures that it would experience throughout its life cycle.
2. Evaluating Performance: Military compliance vibration testing ensures that items will perform properly under harsh vibration conditions.  If your component does not function properly, it could cause a failure of a complicated system. 
3. Reducing Maintenance and Preventing Field Failures:  A robust product will have less or no field failures, reduce downtime and maintenance which is critical for military applications. 

Focusing specifically on vibration testing for military compliance, this article delves into various military standards that are vital in evaluating a product’s durability and ruggedness. These include MIL-STD-167, MIL-STD-202, MIL-STD-750, MIL-STD-810, and MIL-STD-883, each with their specific testing methods for a range of environmental conditions including sinusoidal and random vibration testing.

• MIL-STD-167 Department of Defense Test Method Standard – Mechanical Vibrations of Shipboard Equipment
• MIL-STD-202 Department of Defense Test Method Standard for Electronic and Electrical Component Parts
• MIL-STD-750 Test Methods for Semiconductor Devices
• MIL-STD-810 Department of Defense Test Method Standard for Environmental Engineering Considerations and Laboratory Tests
• MIL-STD-883 Department of Defense Test Method Standard for Microcircuits

MIL-STD-167 applies to equipment installed on Navy ships with conventionally shafted propulsion.  MIL-STD-167-1 covers mechanical vibrations caused by unbalanced rotating components of Naval shipboard equipment.  MIL-STD-167-2 is for mechanical vibrations from reciprocating machinery and lateral, longitudinal vibrations of propulsion systems and shafting. 

MIL-STD-202 establishes uniform methods for testing electronic and electrical component parts.  MIL-STD-202 defines component parts to include capacitors, resistors, switches, relays, transformers, inductors, etc.  This standard is intended to apply only to small component parts, weighing less than 300 pounds or having a root mean square test voltage up to 50,000 volts. 

MIL-STD-750 is intended to apply only to testing semiconductor devices.  Semiconductor devices include such items as transistors, diodes, voltage regulators, rectifiers, tunnel diodes, and other related parts.

Contact DES, where precision meets passion for excellence.

MIL Standard 810 Testing: The DES Commitment

MIL-STD-810, known for its stringent requirements, is crucial for products intended for military use, and at DES, we ensure that these products meet and exceed these rigorous standards.

Our approach to MIL Standard 810 testing is comprehensive and meticulous. We understand that each product has its unique set of challenges and requirements. Therefore, our testing process is not just about meeting the basic compliance standards; it’s about thoroughly understanding the product’s lifecycle and the environmental stresses it will endure.

Our state-of-the-art facilities are equipped to conduct the methods under MIL-STD-810H, ensuring that we cover a wide range of environmental conditions. From high and low temperatures to shock and vibration, our tests are designed to mimic the harsh conditions that products will face in real-world military environments. This thorough testing not only ensures compliance but also aids in enhancing the product’s design and durability.

Choosing DES for MIL Standard 810 testing and all other military compliance testing means partnering with a team that values precision, quality, and customer satisfaction above all else. Our experience and expertise in this field make us a trusted partner for numerous manufacturers, from small component producers to large-scale military equipment manufacturers.

Contact Delserro Engineering Solutions today to learn more about our MIL Standard 810 testing services and how we can assist in bringing your products to the highest standards of military readiness and reliability.

MIL Standard 883: Advanced Testing for Microelectronics

As mentioned in the previous list, MIL-STD-883 is critical for the testing of microelectronics used in military applications. This Department of Defense Test Method Standard for Microcircuits is essential for ensuring that microelectronic devices can withstand the demanding conditions of military use. MIL-STD-883 encompasses a comprehensive suite of test procedures tailored to assess the robustness and reliability of various microelectronic devices, including monolithic, multichip, film, and hybrid microcircuits, as well as microcircuit arrays and their constituent elements.

The standard plays a pivotal role in validating the endurance of microelectronics in extreme environmental conditions. This includes evaluating their performance under conditions of extreme temperature, vibration, and other stress factors that are commonly encountered in military environments.

For manufacturers and designers of microelectronic devices, adhering to MIL-STD-883 is not just about compliance; it’s about guaranteeing the highest levels of performance and reliability of their products in some of the most challenging conditions. This is especially crucial given the increasing complexity and miniaturization of electronic components in military hardware.

Delserro Engineering Solutions (DES) provides comprehensive testing services to ensure compliance with MIL-STD-883. Our advanced testing capabilities help manufacturers navigate the complexities of MIL-STD-883, offering the assurance that their microelectronics meet all necessary military specifications. With our state-of-the-art facilities and technical expertise, we are equipped to handle the rigorous testing requirements of MIL-STD-883, delivering results that manufacturers can trust for their high-performance microelectronic products.

Vibration Testing Lab: Cutting-Edge Solutions by DES

At Delserro Engineering Solutions (DES), our state-of-the-art vibration testing lab is equipped to provide comprehensive solutions for military compliance. Understanding the criticality of these tests for military applications, we offer advanced testing procedures that replicate the exact conditions products will face in the field.

Moreover, DES recognizes the importance of customizing vibration testing to meet the specific requirements of each product and its intended use. Whether it’s testing for land and sea vehicles, aircraft, helicopters, or ground transport, we tailor our vibration testing procedures to ensure the most relevant and rigorous evaluation.

Our expertise extends beyond just executing standard tests. We work closely with our clients to develop comprehensive test plans that not only meet the required standards but also provide valuable insights into product performance and potential areas for enhancement. This approach helps in identifying and rectifying deficiencies early in the design process, saving time and costs, and ultimately leading to a more robust and reliable product.

With DES’s vibration testing lab, clients can expect not just testing, but a partnership that focuses on enhancing the quality and durability of their products. Reach out to us to discuss how we can assist in fulfilling your military vibration testing requirements with our cutting-edge solutions and expert guidance.

Contact DES today to discuss your vibration testing lab requirements.

If you want to learn more about vibration testing, please read these related blog articles:

MIL-STD-810 Vibration Testing Overview

MIL-STD-810: Vibration Testing Category 4 – Truck/Trailer – Secured Cargo

MIL-STD-810: Vibration Testing Category 9 – Aircraft – Helicopter

MIL-STD-810: Vibration Testing Category 7 – Aircraft – Jet

MIL-STD-810: Vibration Testing Category 8 – Aircraft – Propeller

MIL-STD-810: Vibration Testing Category 12 – Fixed Wing Jet Aircraft

MIL-STD-810: Vibration Testing Category 15 – Aircraft Stores

MIL-STD-810: Vibration Testing Category 20 – Ground Vehicles – Ground Mobile

MIL-STD-810: Vibration Testing Category 24 – Minimum Integrity Tests (MIT)

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Electrical connectors are ubiquitous components in the world of electronics, serving as the vital links that enable seamless communication and power transmission within electronic systems. In today’s rapidly advancing technological landscape, ensuring the integrity and reliability of electrical connectors is of paramount importance. Some are exposed to harsh vibration environments such as automotive, aerospace, military, missiles, and rockets. 

A failure or intermittent connection can cause a fault, malfunction, or a system shutdown in a complicated electronic system.  These demanding applications leave no room for error, as even a minor fault or intermittent connection can lead to catastrophic consequences, including system failures, malfunctions, or complete shutdowns. Electrical connector testing includes shock testing, mechanical load testing, and vibration testing, among others.

In this article, we will review the methodologies and standards for effective electrical connector testing in vibrating environments.

Mixed Mode, Random and Sinusoidal Vibration Testing of Electrical Connectors

Electrical connector vibration tests mimic real-world scenarios. Understanding how connectors perform under these complex conditions is crucial for designing robust systems.

How is Electrical Connector Vibration Testing performed?

The specific tests performed on electrical connectors include random, mixed mode, and sinusoidal vibration testing. (See below for links to other blog articles that explain more about the types of vibrations.)  The test equipment consists of an electrodynamic shaker that has an armature or head which produces the required excitations.  A computerized controller sends the precise vibration signals to an amplifier which boosts the signals to drive the shaker head. 

Accelerometers are used to measure the test vibrations and to provide feedback to the controller.  The connectors are mounted to a rigid test fixture that is attached to the armature, a slip table or head expander.  Proper test fixture design is important so that resonances do not occur.  Also, proper mounting of the connectors is important to ensure they are supported sufficiently, and that relative motion does not occur due to poor mounting. 

The vibration test is run at specified frequencies, amplitudes, durations according to the chosen military, automotive, aerospace, etc. specifications.  During the test, the connectors are monitored for discontinuities using an event detector that can monitor discontinuities as quickly as 0.1 microseconds.  After testing is completed, the connectors are inspected for wear and failures. 

DES will promptly deliver a detailed test report that includes the customer’s name and address, the test dates, a summary of the test procedure, equipment & measuring system calibration information, operational test data, test observations & results, color pictures of the vibration test setup and color pictures of any failures. 

Why Perform Electrical Connector Vibration Testing?

The reasons behind subjecting electrical connectors to such rigorous testing are multifaceted. As mentioned above, it helps in identifying potential issues that could lead to field failures and in the development of connectors that can maintain performance in challenging settings. More specific reasons include the following: 

1. Evaluating Performance and Reliability: Vibration testing assesses how well electrical connectors perform and maintain their reliability in diverse vibration environments.
2. Detecting Discontinuities: The testing procedure aims to identify if electrical discontinuities occur when connectors are subjected to typical usage vibrations.
3. Preventing Field Failures: By simulating real-world conditions, it aids in the prevention of field failures caused by issues like fretting fatigue, plating wear, cracks, broken wires, intermittent discontinuities, or loose components.
4. Developing Robust Connectors: Vibration testing is instrumental in the development of stronger and more robust connectors suitable for demanding applications in sectors such as automotive, military, and space industries.

EIA-364-28 and other Electrical Contractor Vibration Test Standards

Adherence to industry standards is paramount when performing electrical connector testing in vibration environments. These standards provide comprehensive guidelines and procedures for conducting rigorous testing. They emanate from a variety of organizations such as the EIA-364-28 standard from the Electronics Industries Alliance. Here are some of the prominent standards employed in the evaluation of electrical connectors’ vibrational resilience:

• EIA-364-28 – Vibration Test Procedure for Electrical Connectors and Sockets
• GMW 3191 – Automotive Connector Test and Validation Specification
• MIL-STD-1344A, Method 2005 – Military Standard, Test Methods for Electrical Connectors
• SAE USCAR-2 – Performance Specification for Automotive Electrical Connector Systems

Precision-Driven Electrical Connector Testing

If you want to learn more about vibration testing, please read these related blog articles:

• Sinusoidal and Random Vibration Testing Primer
• Mixed Mode: Sine on Random Vibration Testing
• High G Level Random Vibration Test
• Extreme Combined Temperature & Vibration Testing

DES has the experience and equipment to perform accurate, repeatable testing of electrical connectors in our controlled, world class accredited lab.  We excel at designing and making customized setups and fixtures.  Contact DES today to discuss your electrical connector vibration testing requirements.

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• MIL-STD 810, Method 516, Shock Testing Overview 
• MIL-STD 810, Method 516, Shock Testing Procedure I – Functional Shock
• MIL-STD 810, Method 516, Shock Testing Procedure II – Transportation Shock

Procedure III is used to determine what shock conditions will cause a product to stop operating, degrade or fail.  The shock magnitudes are systematically increased until a problem occurs.  This procedure can be also performed using environmental temperature conditioning.

This article will assume that the fragility shocks expected to be encountered by the product are not complex transients.  Therefore, the trapezoidal classical shock pulse, as defined in Figure 516.7-11 and Table 516.7-V from MIL-STD-810, Method 516 would be used for Fragility testing.

Figure 516.7-11. Trapezoidal shock pulse configuration and tolerance limits (for use when shock response spectrum analysis capability is not available in Procedure III – Fragility)

Note 1: Am is dependent upon drop height “h.”

Note 2: “h” is the drop height in SI: m (in) and g=9.81 m/s2(386.09 in/sec2)

Table 516.7-V. Trapezoidal pulse parameters

T_D corresponds to the period of the first mounted natural frequency of the item.  During fragility testing, T_D is held constant.  Determination of the fragility level is accomplished by starting at low levels of shock magnitude (A_m) and then proceeding to increase the shock magnitude until:

1. Failure or degradation of the unit occurs.
2. A predefined test goal is reached without failure of the unit under test.
3. A critical level of shock is reached whereby increasing the magnitude will cause a failure at a higher level of shock.

An analysis of the product should be performed prior to testing to:

• estimate its anticipated fragility level
• establish a low starting shock level
• estimate the first mode mounted frequency of the materiel in order to specify the pulse duration T_D.

The product is normally tested in an un packaged, non-operational condition.  The typical procedure when using the trapezoidal classical shock pulse is to first perform calibration shocks using a mass similar in size, weight and center of gravity (CG) of the unit to be tested.  Once the desired shock requirements are met with the calibration mass, the mass is removed and the product to be tested is installed on the shock test machine or fixture.

Operation of the test item and inspection for visual damage is performed before/after each shock.  If testing along more than one axis is required, then testing in the next axis should be completed before proceeding to the next higher shock magnitude.

For more information on Shock Testing or other testing services, contact DES or call 610.253.6637.

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High G Level Random Vibration Profile

Operating the vibration shaker at these levels is difficult because fixture resonances can create control problems causing the test to abort.  First a suitable fixture had to be designed by DES.  Then DES analyzed the fixture using FEA to make sure that it would not have significant resonances below 2000 Hz.  After the fixture was manufactured, it was first tested without product on the shaker to verify its performance.  The fixture performed as designed and did not have any significant resonances that would be imparted into the product under test or cause control problems.  The next step was to mount the product to the fixture and perform the high g level random vibration test.  During the vibration test, the part had to be electrically monitored for operation.  The well designed product passed the test and the customer was very satisfied with the test results and DES’s capabilities.  For more information on Vibration Testing or other testing services, contact DES or call 610.253.6637.

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Meeting these requirements separately would alone be a challenge for any lab.  Meeting these requirements concurrently requires specialized equipment and test setup.  Good insulation is an obvious concern for this test.  The lab must ensure that heat isn’t transferred to the armature of the shaker or else costly damage can occur to the shaker system.  Extreme temperature accelerometers are also necessary if a lab wants to obtain accurate acceleration data.  DES was able to perform this test with successful results and overcome the challenges associated by utilizing their combined temperature and vibration chamber, Figure 1.

For more information on Combined Temperature and Vibration Testing or other testing services, contact DES or call 610.253.6637.

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Vibration Testing Articles

MIL-STD-810 Vibration Testing Overview

MIL-STD-810: Vibration Testing Category 4 – Truck/Trailer – Secured Cargo

MIL-STD-810: Vibration Testing Category 9 – Aircraft – Helicopter

MIL-STD-810: Vibration Testing Category 7 – Aircraft – Jet

MIL-STD-810: Vibration Testing Category 8 – Aircraft – Propeller

MIL-STD-810: Vibration Testing Category 12 – Fixed Wing Jet Aircraft

MIL-STD-810: Vibration Testing Category 15 – Aircraft Stores

MIL-STD-810: Vibration Testing Category 20 – Ground Vehicles – Ground Mobile

Minimum Integrity Testing

MIL-STD-810 Method 514.7, Annex E offers alternative supplemental product vibration testing services. One of which is referred to as minimum integrity testing (MIT). The MIT can be used as a baseline test for materiel either in the early stages of product design or where environmental vibration is unknown. MIT is designed to provide reasonable assurance that materiel can withstand installation/removal, transportation, handling, etc. MIT cannot be used for qualification. Tailored test methods are preferred over MIT.

Figures 1 and 2 show the vibration profiles outlined for MIT in Method 514.7, Annex E. Figure 1 is a random vibration profile for general use, while Figure 2 is a sinusoidal vibration profile for helicopter material. They were not developed from application environments.

The material under test should be hard mounted to a fixture. These vibration tests should not be applied through vibration isolation. The MIT should not be applied to large material because unnecessarily high loads could be induced in mounting and chassis structures, while higher frequency vibrations at subassemblies are low. In cases where the material is large, the MIT should be applied to subassemblies. The maximum test weight of a materiel or subassembly should be approximately 36 kg (80 lb) when using MIT.

According to MIL-STD-810G w/Change 1, experience has shown that materiel that withstands these exposures typically functions satisfactorily in the field. Failure to pass an MIT does not imply that the materiel will fail in its service environment. Failure to function subsequent to exposure to an MIT test should serve as grounds to make an attempt to define the test environment and make an effort at developing a tailored test.

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MIL-STD-810 Vibration Testing Overview

MIL-STD-810: Vibration Testing Category 4 – Truck/Trailer – Secured Cargo

MIL-STD-810: Vibration Testing Category 9 – Aircraft – Helicopter

MIL-STD-810: Vibration Testing Category 7 – Aircraft – Jet

MIL-STD-810: Vibration Testing Category 8 – Aircraft – Propeller

MIL-STD-810: Vibration Testing Category 12 – Fixed Wing Jet Aircraft

MIL-STD-810: Vibration Testing Category 15 – Aircraft Stores

Category 20 of Method 514.7 Vibration testing details the vibration profile of ground mobile environments which features a broadband of random vibration with peaks and valleys.  The peaks and valleys represent a number of different factors including but not limited to differential road terrain, vehicle speed, structural characteristics and suspension.  For tracked vehicles, MIL-STD-810G recommends that testing use a random-on-random vibration strategy.  Figure 1 illustrates a representative plot of a tracked vehicle vibration profile.  The vibration test durations are determined from the Life Cycle Environment Profile.

To learn more about our vibration testing services, please feel free to contact us with your inquiry. Feel free to explore our site to learn about our full line of product testing services, and the product testing standards that we can help our clients with.

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MIL-STD-810 Vibration Testing Overview

MIL-STD-810: Vibration Testing Category 4 – Truck/Trailer – Secured Cargo

MIL-STD-810: Vibration Testing Category 9 – Aircraft – Helicopter

MIL-STD-810: Vibration Testing Category 7 – Aircraft – Jet

MIL-STD-810: Vibration Testing Category 8 – Aircraft – Propeller

MIL-STD-810: Vibration Testing Category 12 – Fixed Wing Jet Aircraft

Category 15 of Method 514.7 Vibration testing describes the different vibratory environments aircraft stores may experience in an aircraft.  Three environments are detailed in category 15; captive flight – external carriage, captive flight – internal carriage and free flight.

Captive flight – external carriage include stores carried externally on a jet aircraft.  The overall vibration profile arises from four sources; engine noise, in-flight aerodynamic turbulence, vibration transmitted through attaching structures and internal store vibration.  Engine noise is highest at the boundary layer of the exhaust jet plume.  At this point there is turbulence between the exhaust air and ambient air and is at its maximum during takeoff.  In-flight aerodynamic turbulence do not greatly affect overall store vibration, however, they may cause other structures such as tailfins to produce vibrations that are then transmitted to the store.  These vibrations, as it states in category 15 of method 514.7, are a “low frequency system” and are often characterized as buffet vibration, Figure 2.  “Buffet vibration is typically concentrated between 10 and 50 Hz” and “is dominated by store structural resonances.”  Finally stores are also susceptible to internal vibration from elements such as rotating machinery.

Captive flight – internal carriages generally don’t experience harsh vibration levels unless the bay is opened during flight.  “This event is referred to as a cavity resonance and results in high levels of turbulence inside the bay.”  This vibration is characterized as a wide band spectrum with high spikes across it.  Low frequency spikes (<100 Hz) are not expected to be of issue for most stores, however, high frequency spikes can be very dangerous.

Free flight vibration will typically be experienced by stores that are deployed from the aircraft.  Free flight vibration is comprised of engine noise vibration, onboard vibration and varying turbulence similar to that of captive flight.

Figure 1 below, shows the profile for store vibration exposure on jet aircrafts.  Figure 2 shows the vibration profile for buffet vibration response.  W0, W1 and W2 in Figures 1 and 2 are calculated from rather complicated tables and formulas within Category 15.  The vibration testing durations are determined from the Life Cycle Environment Profile.

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MIL-STD-810 Vibration Testing Overview

MIL-STD-810: Vibration Testing Category 4 – Truck/Trailer – Secured Cargo

MIL-STD-810: Vibration Testing Category 9 – Aircraft – Helicopter

MIL-STD-810: Vibration Testing Category 7 – Aircraft – Jet

MIL-STD-810: Vibration Testing Category 8 – Aircraft – Propeller

Category 12 of Method 514.7 Vibration testing begins the operational vibration exposure section (Annex D) of Method 514.7 and defines the tests necessary for products to operate in and survive vibration environments.  Category 12 outlines the vibration environment for products installed in fixed wing jet aircrafts (except if said product is engine-mounted).  The vibration environment of installed products in fixed wing jet aircrafts is made up of 4 components; airframe structural response, jet noise and aerodynamically induced vibration, cavity noise induced vibration, material induced vibration.

Airframe structural response dynamics are from the response of flexible airframe structures to typical events such as take-off and landing impacts.  Jet noise and aerodynamically induced vibration are determined primarily by altitude and speed where jet noise dominates over subsonic speeds at lower altitudes and transonic speeds at higher altitudes.  Aerodynamically induced vibration typically dominates at transonic speeds at lower altitudes and supersonic speeds at any altitude.  Cavity noise induced vibration is caused by openings in the aircraft skin where external airflow is allowed to pass through.

As you can imagine, the fluctuating pressures produce turbulent airflow causing vibration to the surrounding parts.  Finally material induced vibration is any vibration that is created from surrounding product operation.  Examples are motors, pumps and gear boxes.

Figure 1 illustrates the typical vibration profile for products installed in fixed wing jet aircraft.  The parameters of the plot are calculated using equations outlined below in Table 1.  Typical test durations are 1 hour per axis for endurance testing or 5 to 10 minutes per axis to demonstrate that products will operate acceptably in these environments.

To learn how Delserro Engineering Solutions can help you test for exposure issues in your product through our vibration testing services, or our range of dynamic testing services, please contact us today.

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MIL-STD-810 Vibration Testing Overview

MIL-STD-810: Vibration Testing Category 4 – Truck/Trailer – Secured Cargo

MIL-STD-810: Vibration Testing Category 9 – Aircraft – Helicopter

MIL-STD-810: Vibration Testing Category 7 – Aircraft – Jet

Category 8 of Method 514.7 simulates the vibration environment for cargo carried in propeller aircraft.  The vibration environment generated from propeller aircraft are dominated by high amplitude approximately sinusoidal spikes at propeller passage frequency and harmonics.  Lower level wide band random vibration is also present due to air flow over the aircraft.  Collectively, these phenomena are superimposed to create the vibration profile for cargo carried on propeller aircraft resulting in a Mixed Mode Vibration Test.

Figure 1 and Table 1 show the vibration profile for this environmental condition.  The test durations are obtained from the products life cycle environment or one hour per axis if the duration is unknown.

To learn more about our vibration testing services, please feel free to contact us with your inquiry. Feel free to explore our site to learn about our full line of product testing services, and the test standards that we can help our clients with.

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