url("//cdn2.editmysite.com/fonts/SQ_Market/sqmarket-medium.woff") format("woff"); These material assemblies are either installed in, or transported by wheeled or tracked vehicles. "Mobile Site" This fact means that in a world filled with energy and movement, vibrations or the oscillating responses of objects when moved from a position of rest are the norm. Secured Cargo. ); SAE J2380 (2013): It provides a test procedure for characterizing the effect of long-term, road-induced vibration on the performance and service life of electric vehicle batteries. font-style: normal; It is also applied to the free flight phases of ground or sea-launched missiles. conditions. //-->. Vibration tests are performed to: Develop materiel to function in and withstand the vibration exposures of a life cycle including synergistic effects of other environmental factors, materiel duty cycle, and maintenance. It is a method of testing that allows us to calculate the natural frequencies (modes), modal masses, modal damping ratios and mode shapes of a test structure. Recommended troubleshooting procedure. VIBRATION ANALYSIS PROCEDURE A vibratory system is a dynamic one for which the variables such as the excitations (inputs) and responses (outputs) are time dependent. From sub-atomic particles all the way up to skyscrapers, internal movements and motions resulting from the absorption of energy make all objects vibrate to some degree. It is good practice to completely understand the reason for conducting the test. esting and Commissioning Procedure For Motors // Photo by TECO Middle East (TME) The measurements shall be carried out with an instrument conforming to ISO 2954 (10-1000 Hz frequency range). Rotary Vibration Test Procedures We perform the rotary vibration test on a mechanical rotary vibration machine. Difficulties encountered usually concentrate on the differences between sinusoidal vibration (sine testing) and random vibration testing. if (document.readystate === 'complete') { What is the Test Item Configuration? Our capabilities include testing to commercial and military vibration testing standards. This procedure is used to test material that is not secured to the carrying vehicle. Often truck random vibration profiles are testing in conjunction with aircraft profiles to represent transport before and after air transport. This creates a simulation of both the vibration environment and the dynamic response of the test material to the environment. document.addEventListener('DOMContentLoaded', function() { In addition, elastic structural interactions with propulsion systems and flight control systems can produce low-frequency, high-deflection flight instabilities. Procedure III is an alternative for ground transportation. Vibration is most commonly measured using a ceramic piezoelectric sensor or accelerometer. Create your own unique website with customizable templates. There has always been some confusion concerning the various tests offered to the vibration testing engineer by the vibration test labs. Loose Cargo. Potentially, such testing can include all environmental factors related to wheeled vehicle transport, including: vibe testing, shock, temperature, humidity, pressure, etc. Prepare your individual measurement system components to be clean, neat, orderly and ready for installation. When this occurs, allowances should be provided in the test setup, and in the vibration excitation system, to account for this. Here we are going to deal only with impact hammer testing. Part 2, PROCEDURES, covers measurement procedures of sound and vibration testing for building systems. The random vibration test profiles are executed in all three axes for a duration ranging from 9 minutes to 38 hours. This test will determine reliability of the tested specimen and ensure it will operate as intended in real-world situations. Get Started APPENDIX F. VIBRATION TESTING PROCEDURE Appendix F. SPS-F-1 of 14 VIBRATION PERFORMANCE TESTING. This is commonly done using either impact hammer testing or shaker testing. Therefore, it is necessary to conduct on-machine vibration testing and analysis to assess its relationship with the sampling frequency, scanning parameters, and filtration operations in postprocessing. It aids in defining the vibration environments that material may be exposed to throughout a life cycle. Vibration analysis is defined as a process for measuring the vibration levels and frequencies of machinery and then using that information to analyze how healthy the machines and their components are. This motion takes place in a vertical plane. The norm describes the test procedure for airborne equipment. Mil-810 vibration is the standard for conducting vibration laboratory tests. Before a product or machinery can be used in its intended environment, it needs to go through the vibration testing procedure. Procedure I is not applied to fixed wing aircraft carriage or free flight phases. Other configuration modifications of the shipment are also considered. Procedure 3H: Performance Test for Products or Packaged-Products in Mechanically Handled Bulk Transport Containers Basic Requirements: atmospheric conditioning, random vibration and shock testing. }); Ensure the test item configuration includes appropriate numbers and groupings of items. } The basic information required to conduct a vibration test is listed below: Know what structural mode shapes will be present in testing your new itemKnow what frequency range  you anticipate  measuringKnow what “G” level amplitude you anticipate measuringKnow what environmental conditions the test will be conducted withinSelect the correct sensor technologies to use in your test programDetermine the most useful style of sensor mounting and cable routing to useKnow what methods of data acquisition and data reduction will be usedPrepare your individual measurement system components to be clean, neat, orderly and ready for installation. var windowHref = window.location.href || ''; } Vibration test procedure features A vibration test can reproduce movements during load and unload, vibrations in the vehicle and horizontal accelerations/decelerations incurred in transport by road, plain, train or sea damage and deform packaging … Procedure IV of mil-std 810 vibration uses standard vibration laboratory exciters, or shakers. A structural vibration test on a new design is the premise of the test we are discussing. The test conductor should make all attempts to discuss this information with the design team. font-weight: 500; Choose what specific exciters to use in the shaker testing based on the size and mass of test items and fixtures. Vibration Analysis ¾All machines vibrate ¾The vibration ‘signature’ changes as the condition changes. Vibration Testing For vibration testing, you need • an excitation source • a device to measure the response • a digital signal processor to analyze the system response i) Excitation sources Typically either instrumented hammers or shakers are used. Shakers are chosen based on the size and mass of test items and fixtures. Accelerometers are full-contact transducers typically mounted directly on high-frequency elements, such as rolling-element bearings, gearboxes, or spinning blades. In this test, the cargo is free to bounce, scuff and collide with other cargo, and the sides of the vehicle. Create your own unique website with customizable templates. Anytime a piece of machinery is running, it is makin… It also applies to previous versions of the standard including MIL-STD 810G random vibration. The test item is supported by a test frame independent of the shaker table. if (document.cookie.match(/(^|;)\s*is_mobile=1/)) { The test item is configured for each test as it will be in the corresponding life cycle phase. Random vibration is also more realistic than sinusoidal vibration testing, because random simultaneously includes all the forcing src: Carrying vehicles include trucks, trailers, or tracked vehicles and is not secured to the carrying vehicle. Therefore, various parameters of the test, the test environment, the instrumentation setup, instrumentation calibration, data collection, data reduction and data analysis are extremely critical to conducting a viable test program. In this procedure, the specified vehicle type is used to provide the mechanical excitation to the test material. The previous procedures are used for other portions of the store’s life cycle as needed. The basic information required to conduct a vibration test is listed below: Know what structural mode shapes will be present in testing your new item, Know what “G” level amplitude you anticipate measuring, Know what environmental conditions the test will be conducted within, Select the correct sensor technologies to use in your test program, Determine the most useful style of sensor mounting and cable routing to use, Know what methods of data acquisition and data reduction will be used. This procedure is applicable to large assemblies or groupings that form a high proportion of vehicle mass. This should happen at a frequency of 5 Hz. Acoustic Testing. Vibration Testing Rocket boosters and spacecraft are subject to intense acoustic environments during launch, which induce high levels of vibration in structural elements and equipment. Packages will be subjected to a total of 14,200 vibratory impacts. Octave and fractional octave bands have been used for several decades now in the characterization of acoustic energy in various applications. With the motor at normal operating temperature, the vibration velocity shall not exceed 2.8 mm/s RMS, or 4 mm/s PEAK, in any direction. APPENDICES. An acoustic test, or acoustic testing, has changed over the years. if (windowHref.indexOf('?') This procedure is directly from MIL-STD 810H, but is accurate for previous versions including MIL-810G vibration. It is good practice to completely understand the reason for conducting the test. ¾Vibration analysis can … 8.0 Vibration: Aircraft type dependent test checks the effects of vibration and the equipment's ability to operate during all vibration scenarios. 9.0 Explosion proofness: These tests subject the test article to an environment under vacuum, with a gaseous mixture of combustibles. Consider the frequency range required,and the force, acceleration, velocity, and displacement required. The test surfaces may include designed test tracks, typical highways, or specific highways between given points. In cases representing transportation, all packing, shoring, and padding are duplicated in the vibration test lab. This procedure applies to ground vehicles as well as fixed and rotary wing aircraft. This method is limited to consideration of one mechanical degree-of-freedom at a time. This is often also known as Modal Testing. Sensor location is important as the new design has not been tested before. Simulation of the environment used for Procedure II, requires use of a package tester. This includes synergistic effects of other environmental factors, material duty cycle, and maintenance. Random testing is the key testing method for this kind of application. You can diagnose a vibration problem in two steps. This enables driving the test item directly, or through a fixture. url("//cdn2.editmysite.com/fonts/SQ_Market/sqmarket-medium.woff2") format("woff2"), From instrument panels to seats inside the car and from air-bag sensors to fuel injection pumps in the engine compartment, many automotive components are being tested to precise vibration patterns and levels. vibration test procedure It is good practice to completely understand the reason for conducting the test. "    " + For this procedure, the test item is secured to a fixture or a vibration exciter, and vibration is applied to the test item as an input. It is also applied to free flight portions of the environmental life cycles of all aircraft stores. For best results, ensure the package tester is large enough to accommodate the dimensions and weight of specific test items. The transportation configuration may be different for different modes of transportation. Generally, measured vibration data is not used to define this test, but it is often acquired during this test. This test replicates the repetitive impact environment incurred by cargo transported under these conditions. } else { This procedure is applied to fixed wing aircraft carriage. This procedure assumes no relative motion between the vehicle cargo deck, or cargo compartment and the... Stacked Cargo. There is considerable information that can be obtained from reference books, vibration societies, and the search for information on the web. Stacking or bundling of sets or groups of material items may affect the vibration transmitted to individual items. Such information will help determine the proper location of sensors so that they will be responsive to the structure vibration amplitudes. This procedure applies to not just 810H random vibration. It is also applicable to material that forms an integral part of the vehicle. @font-face { This procedure is directly from MIL-STD 810H, but is accurate for previous versions including MIL-STD-810G vibration. This applies directly to material that is tied down or secured. Set up the vibration table for an acceleration at a specific level, in a way that the sample to be tested separates from the table causing repetitive shocks. Some typical symptoms of problems caused by vibration are: This procedure is used to test material that is being transported as secured cargo or deployed for use on a vehicle. Customers, end users or manufacturers who incorporate a component into an assembly, often define vibration test specifications and procedures themselves. Vibration test profiles . This test method establishes procedures for determining the effect of sinusoidal vibration, within the specified frequency range, on switch contacts, mounting hardware, adhered component parts, solder or heat stakes, tactile devices, and cable or ribbon interconnects associated with a membrane switch or membrane switch assembly. This package tester should impart a 25.4 mm, or 1.0 inch, peak-to-peak, circular synchronous motion to the table. Test II: Loose Cargo Transportation This condition applies to material/products “to be carried in/on trucks, trailers, or tracked vehicles and not secured to (tied down in) the carrying vehicle. The general vibration includes random vibration. Strike a tuning fork and the soundyou will hear would be of a single sinusoidal wave produced at a specificfrequency. document.write( The response of a vibrating system generally depends on the initial conditions as well as the external excitations. windowHref += '&'; The vehicle is then driven over the test surface in a manner that reproduces the transportation or service conditions. While the inner-workings and formulas used to calculate various forms of vibration can get complicated, it all starts with using an accelerometer to measure vibration. Vibration is then applied to the test item as an input at the fixture/test item interface. } else { Therefore, various parameters of the test, the test environment, the instrumentation setup, instrumentation calibration, data collection, data reduction and data analysis are extremely critical to conducting a viable test program. The most realistic alternative for truck, trailer, or other ground transportation requires the transportation vehicle and a full cargo load. Dynamic deflections may cause impact to elements and/or disruption of function. All final vibration readings used for acceptance will be taken with the machinery under operating/loaded conditions. //