ISO 16750-3-2012 pdf download.Road vehicles — Environmental conditions and testing for electrical and electronic equipment—Part 3:Mechanical loads.
This part of ISO 16750 applies to electric and electronic systems/components for road vehicles. Itdescribes the potential environmental stresses and specifies tests and requirements recommended forthe specific mounting location on/in the vehicle.
This part of ISO 16750 describes mechanical loads.
2Normative references
The following referenced documents are indispensable for the application of this document.For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenceddocument (including any amendments) applies.
ISO16750-1,Road vehicles—Environmental conditions andtesting for electricalandelectronic equipmentPart 1: General
IEC 60068-2,6,Environmental testing — Part 2-6:Testing, Test Fc: Vibration (Sinusoidal)
IEC60068-2,14,Basic environmental testing procedures—Part2-14:Tests—Test Nb:Changeof temperature
gaa-bcnrc
IEC 60068-2,64, Environmental testing —Part 2-64:Test methods —Test Fh — Vibration, broad-band
random (digital control) and guidance
IEC 60068-2,80,Environmental testing —Part 2-80:Tests —Test Fi: Vibration —Mixed mode testingIEC 60068-2-31,Environmental testing procedures — Part 2:Tests;Test Ec: Free fall,Clause 5.2
3Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16750-1 apply.
4 Tests and requirements
4.1Vibration
4.1.1 General
The vibration test methods specified consider various levels of vibration severities applicable to on-board electrical and electronic equipment. It is recommended that the vehicle manufacturer andsupplier choose the test method, the environmental temperature and vibration parameters dependingon the specific mounting location.
Following the expressions in MIL-STD please notice:
When applied properly, the environmental management and engineering processes described in this partof ISO 16750 can be of enormous value in generating confidence in the environmental worthiness andoverall durability.However, it is important to recognize that there are limitations inherent in laboratorytesting that make itimperative to use proper caution and engineeringjudgement when extrapolating theselaboratory results to results that may be obtained under actual service conditions. In many cases, real-world environmental stresses [singularly or in combination) cannot be duplicated practically or reliably intest laboratories.Therefore, users of this part ofIS0 16750 should not assume that a system or componentthat passes laboratory tests of this part of ISO 16750 would also pass field/fleet verification trials.
_“The specified values are the best estimation one can get up to the moment when results from
measurements in the car are received – but they do not replace a car measurement!”
The specified values apply to direct mounting in defined mounting locations. Using a bracket formounting can result in higher or lower loads.If the device under test (DUT) is used in the vehicle with abracket then all vibration and mechanical shock test shall be done with this bracket.
Carry out the vibration with the DUT suitably mounted on a vibration table. The mounting method(s)used shall be noted in the test report.Carry out the frequency variation by logarithmic sweeping of 0,5octave/minute for sinusoidal tests and the sinusoidal part of sine on random tests. The scope of therecommended vibration tests is to avoid malfunctions and breakage mainly due to fatigue in the field.Testing for wear has special requirements and is not covered in this part of lSO 16750.
Loads outside of the designated test frequency ranges are to be considered separately.
NOTE Deviations from the load on the DUT can result, should vibration testing be carried out according tothis part of lSO 16750on a heavy and bulky DUT, as mounting rigidity and dynamic reaction on the vibrator tableexcitation are different compared to the situation in the vehicle.This deviation can be minimized by applying theaverage control method (see Annex A).
Application of the weighted average control method according toIEC 60068-2,64 is to be agreed upon.Subject the DUT during the vibration test to the temperature cycle according to IEC 60068-2,14, withelectric operation according to diagram 1.Alternatively, a test at constant temperature may be agreed on.Operate theDUTelectricallyasindicatedinFigure 1atTmin (shortfunctionaltestaftertheDUTcompletelyreached Tmin).This functional test shall be as short as possible – only long enough to check the properperformance of the DUT.This minimizes self-heating of the DUT.Additional electrical operation of theDUT between 210 min and 410 min of the cycle (see Figure 1).ISO 16750-3 pdf download.