MIL-STD-202 Vibration Testing
The purpose of MIL-STD-202 vibration testing is to determine the effects of vibration on component parts, within the predominant frequency ranges and magnitudes encountered during field service. Most vibration encountered in field service is not of a simple harmonic nature. However, tests based on vibrations of this type have proved sufficiently useful for determining critical frequencies, and modes of vibration. This and other determined data are necessary for planning protective steps against the effects of undue vibration.
During the life cycle, vibration can cause loosening of parts or relative motion between parts in the specimen. This can produce operating characteristics, noise, wear, and physical distortion that are objectionable. Such things often result in fatigue and failure of mechanical parts.
Keystone Compliance is a vibration test lab with significant mil-std-202 vibration test experience. Our vibration laboratory and test engineers understand the nuances of the vibration profiles and vibe testing.
The following information is extremely technical in nature. It was derived from test method 201 of version G of Mil-202 vibration section. Even though the language is from mil-202g vibration, it applies to previous versions of the standard.
What is the Procedure For Mil-Std 202 Vibration Tests?
Prior to vibration testing, the specified tests or measurements shall be made. The specimens shall be mounted as specified using suitable mounting apparatus and testing fixtures. This ensures that mounting is free from resonances over the test frequency range.
The specimens shall be subjected to a simple harmonic motion having an amplitude of 0.03 inch. This results in an 0.06 inch maximum total excursion. The frequency must be varied uniformly between the approximate limits of 10 and 55 hertz (Hz). The entire frequency range, from 10 to 55 Hz and back to 10 Hz, shall be traversed in approximately 1 minute.
Unless otherwise specified, this motion shall be applied for a period of 2 hours in each of 3 mutually perpendicular directions. This results in a total of 6 hours of motion application. If applicable, this test shall be made under electrical-load conditions.
In the previous Mil-202H vibration issue of this method test certain conditions required shorter test lengths. Test conditions A and B refer to a test length of 5 hours and 2.5. This procedure language is taken directly from MIL-STD 202G. The procedure is similar to other versions of the standard including MIL-STD 202H. It complies with the prescriptions of MIL STD-810.
What are the Detailed Requirements of Mil-202G Vibration Testing?
Measurements: According to Mil-202 vibration, the specified measurements shall be made both during and after vibration. There should be details regarding tests and measurements prior to vibration included in the individual specification. The specification should also include tests and measurements that occurred during and after vibration.
If the duration of vibration is different than what was already specified it should be detailed. The direction of motion should also be detailed, if it is different than what was already specified. The method of mounting should be included in the individual specification. Lastly, if applicable, a note should be made of the electrical-load conditions.
What are the Effects of the Environment?
It is important that all tests take place in an appropriate vibration laboratory environment utilizing the proper test equipment. Vibration results in dynamic deflections of and within material. Such dynamic deflections coupled with their associated velocities and accelerations may cause or be a contributing factor to structural fatigue. It may also lead to mechanical wear of structures, assemblies, and parts.
In addition, dynamic deflections may result in impacting of elements and/or disruption of function. Some typical symptoms of problems caused by these dynamic deflections include:
- Electrical shortages
- Chafed wiring
- Excessive electrical noise
- Intermittent electrical contacts
- The loosening of fasteners and components
- The failure of components
- The migration of particles and failed components
- Particles and failed components may lodge in circuitry or mechanisms
- Optical or mechanical misalignment
- Cracked and/or broken structures
- The deformation of seals
- Fretting corrosion in bearings
This list is not intended to be comprehensive. It demonstrates a few possible problems that may arise when a component fails to meet vibration compliance standards. MIL-STD 202G and MIL-STD 202H vibration provided the appropriate guidelines for meeting these compliance test standards.
Keystone Compliance has been recognized as one of the best vibration testing labs in the country. Our capabilities include testing to commercial and military vibration testing standards. With one of the best vibration labs we use only state of the art vibration test systems. Our vibration laboratory and test engineers understand the nuances of the vibration profiles and vibe testing.
Looking to get a vibration certification for your product? Talk to our experts to develop a streamlined test plan and receive a professional and affordable quote. Work with certified vibration analysts that understand the requirements of military vibration testing standards. Contact us to learn why so many manufacturers rely on Keystone Compliance to meet their vibration testing needs.
Looking for other MIL-STD-202 compliance tests? Click on a link below to learn more about the other test methods.
- MIL-STD-202 Test Method 101 Salt Atmosphere (Corrosion)
- MIL-STD-202 Test Method 103 Humidity (solid state)
- MIL-STD-202 Test Method 104 Immersion
- MIL-STD-202 Test Method 105 Barometric Pressure
- MIL-STD-202 Test Method 106 Moisture Resistance
- MIL-STD-202 Test Method 107 Thermal Shock
- MIL-STD-202 Test Method 108 Life (at elevated ambient temperature)
- MIL-STD-202 Test Method 109 Explosion
- MIL-STD-202 Test Method 110 Sand and Dust
- MIL-STD-202 Test Method 111 Flammability (external flame)
- MIL-STD-202 Test Method 112 Seal
- MIL-STD-202 Test Method 201 Vibration
- MIL-STD-202 Test Method 203 Random Drop
- MIL-STD-202 Test Method 204 Vibration, High Frequency
- MIL-STD-202 Test Method 206 Life (rotational)
- MIL-STD-202 Test Method 207 High-Impact Shock
- MIL-STD-202 Test Method 208 Solderability
- MIL-STD-202 Test Method 209 Radiographic Inspection
- MIL-STD-202 Test Method 210 Resistance to Soldering Heat
- MIL-STD-202 Test Method 211 Terminal Strength
- MIL-STD-202 Test Method 212 Acceleration
- MIL-STD-202 Test Method 213 Shock (specified pulse)
- MIL-STD-202 Test Method 214 Random Vibration
- MIL-STD-202 Test Method 215 Resistance to Solvents
- MIL-STD-202 Test Method 216 Resistance to Solder Wave Heat
- MIL-STD-202 Test Method 217 Particle Impact Noise Detection
- MIL-STD-202 Test Method 301 Dielectric Withstanding Voltage
- MIL-STD-202 Test Method 302 Insulation Resistance
- MIL-STD-202 Test Method 303 DC Resistance
- MIL-STD-202 Test Method 304 Resistance-Temperature Characteristic
- MIL-STD-202 Test Method 305 Capacitance
- MIL-STD-202 Test Method 306 Quality Factor
- MIL-STD-202 Test Method 307 Contact Resistance
- MIL-STD-202 Test Method 308 Current-Noise Test for Fixed Resistors
- MIL-STD-202 Test Method 309 Voltage Coefficient of Resistance Determination Procedure
- MIL-STD-202 Test Method 310 Contact-Chatter Monitoring
- MIL-STD-202 Test Method 311 Life, Low Level Switching
- MIL-STD-202 Test Method 312 Intermediate Current Switching