1、 SAE/USCAR24-2April 2013USCAR Inflator Technical Requirements and ValidationISBN: 978-0-7680-8013-1 _ The research data, analysis, conclusion, opinions and other contents of this document are solely the product of the authors. Neither the SAE International (SAE) nor the United States Council for Aut
2、omotive Research (USCAR) certifies the compliance of any products with the requirements of nor makes any representations as to the accuracy of the contents of this document nor to its applicability for purpose. It is the sole responsibility of the user of this document to determine whether or not it
3、 is applicable for their purposes. Copyright 2013 USCAR Printed in U.S.A. All rights reserved. QUESTIONS REGARDING THIS DOCUMENT: (248) 273-2470 FAX (248) 273-2494 TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX (724) 776-0790 AEROSPACE SAE/USCAR-24 REVISION 2 Issued 2004-06 Revised 2013-04 USCAR INFL
4、ATOR TECHNICAL REQUIREMENTS AND VALIDATION SUMMARY OF CONTENTS 1. INTRODUCTION: 6 1.1 Scope: . 6 1.2 Preface Definitions: . 6 1.3 Changes to this Document: . 7 2. APPLICABLE DOCUMENTS: . 7 3. REQUIREMENTS: 8 3.1 General Requirements: . 8 3.1.1 General: . 8 3.1.2 Quality: 8 3.1.3 Production Requireme
5、nts: . 8 3.1.4 Reliability: 8 3.1.5 Heavy Metal Compounds Reporting and Recycleability Requirements: . 8 3.1.6 Informational Requirements: . 8 3.2 Functional Requirements: . 10 3.2.1 General Inflator Requirements: . 10 3.2.2 Inflator Structural Integrity: 10 3.2.3 Effluents: . 11 3.2.4 Inflator Flam
6、ing: 16 3.2.5 Autoignition, High Temperature Oven Performance/Autoignition of Heat Aged Inflators: 18 3.2.6 Sequential Test Series: . 19 3.2.7 Inflator Performance and Variability Limits: . 20 3.2.8 Propellant Stability: 22 3.2.9 Hermeticity: . 23 3.2.10 Dual Stage Inflator(s) - Additional Requireme
7、nts: . 24 4. VALIDATION: 24 4.1 Design Verification/Production Validation Report Format: 25 4.2 Deviations From Test Procedure: . 25 4.3 Design Verification Process: . 25 4.3.1 DV Program Sequence: 25 4.3.2 DV Test Plan: 26 4.4 Production Validation Process: . 26 4.4.1 PV Program Sequence: 26 4.5 Va
8、lidation Tests a) shall not leak per Section 5.2.3.1, Leak Test, b) shall Maintain a bridgewire resistance as specified in the USCAR Initiator Specification of current issue, or as approved by the Responsible Vehicle Engineering Organization. In addition those inflators deployed in a tank, or open a
9、ir: c) shall deploy as intended per Section 5.2.3.7, Closed Tank Test or Section 5.2.3.6, Open Air Test, d) should meet the tank wash requirements as indicated in the Appendix B, DV/PV Validation Test Matrix, and Section 3.2.3.3 Inflator Particulate (Tank wash derived), and e) shall meet all require
10、ments of Section 3.2.7, Inflator Performance and Variability Limits where ballistic curves are obtained. f) Shall not show any loss in the measured strength or ballistic integrity of the propellant as demonstrated by ballistic performance and/or accepted break or crush strength measurement methods o
11、f live tear down inflators. (Limited dusting that does not appreciably affect ballistic performance is excepted) 3.2.6.1 Inflator Thermal Shock Resistance: a) Expose inflators to 200 cycles of -40 C to +90 C thermal shock profile as specified in Section 5.2.4.8.1, Inflator Thermal Shock Resistance T
12、est. 3.2.6.2 Inflator Dynamic Shock Resistance: Expose inflators to the dynamic shock profile specified in Section 5.2.4.8.2, Dynamic Shock Test. 3.2.6.3 Inflator Drop Resistance: Expose Inflators to the drop environments specified in Section 5.2.4.8.6, Drop Test. 3.2.6.4 Inflator Vibration/Temperat
13、ure Resistance: a) Expose inflators to the vibration and temperature profiles specified in Section 5.2.4.8.3, Vibration - Temperature Cycle Test. 3.2.6.5 Inflator Salt Spray Resistance: Expose inflators to the salt spray profile specified in Section 5.2.4.8.5, Salt Spray Test. 3.2.6.6 Inflator Humid
14、ity Resistance: a) Expose inflators to the humidity profile specified in Section 5.2.4.8.4, Humidity Resistance Test. SAE/USCAR-24 REVISION 2 Revised 2013-04 USCAR INFLATOR TECHNICAL REQUIREMENTS AND VALIDATION - 20 - 3.2.7 Inflator Performance and Variability Limits: When Inflators are conditioned
15、per Section 5.2.3.7, Closed Tank Test of this document, placed in a closed tank filled with ambient air at room temperature and pressure, and activated using a minimum of the “All-Fire“ current of the initiator in use, the Inflator requirements of this section shall be met. 1. Closed tank inflator c
16、urves per the following shall be provided to the Responsible Vehicle Engineering Organizations by the Inflator Supplier for all validation tests: a) Baseline deployments at each temperature (full and first stage output for dual stage inflators); Scatter plots for each group with overlays of the mean
17、 curve, 3 curves and performance windows. b) Environmentally conditioned inflators deployed at each temperature; Comparison plot for each group with overlays of the mean curve and performance windows. c) Data tables showing performance against the specified windows established in Table 3.2.7.A, Infl
18、ator Variability Limits, and Table 3.2.7.B, Ballistic Variability Limits . 2. The tolerances shown in Table 3.2.7.A, Inflator Variability Limits, and Table 3.2.7.B, Ballistic Variability Limits shall be met at room temperature, hot temperature, and cold temperature by the baseline inflators full and
19、 staged output(s) ( 3 of the mean of the baseline deployment groups at each temperature, shall fall within each defined window excepting TTFG) when deployed as specified in Section 5.2.3.7, Closed Tank Test. (Refer to Appendix F for examples.) TTFG shall be evaluated based on attributes of each indi
20、vidual curve. 3. The tolerances shown in Table 3.2.7.A, Inflator Variability Limits, and Table 3.2.7.B, Ballistic Variability Limits shall be met at room temperature, hot temperature, and cold temperature by each individual inflator curve (for full and first stage deployments for dual stage inflator
21、s) after inflator exposure to environments (the individual ballistic curves of each inflator shall fall within each defined window) as specified in the Section 5, Test Requirements when deployed as specified in Section 5.2.3.7, Closed Tank Test. (Refer to Appendix F for examples.) 4. A program speci
22、fic closed tank mean curve shall be determined by the Responsible Vehicle Engineering Organizations from an appropriate baseline inflator tank deployment series such as the baseline tests of the PV or other as determined by the Responsible vehicle Engineering Organization. For dual stage inflators f
23、ull output and/or first stage output should be chosen for evaluation based on program specific needs by the Responsible vehicle Engineering Organization. Ongoing production Lot Acceptance Tests shall be measured against the tolerances determined from Table 3.2.7.A, Inflator Variability Limits, and T
24、able 3.2.7.B, Ballistic Variability Limits for the vehicle specific baseline mean curve. Each individual Lot Acceptance Tests inflator curve shall fall within each defined window. Where individual inflator curves do not fall with in each established window a minimum of fifteen additional (15) sample
25、s may, at the discretion of the manufacturer, be deployed at the temperature of the specific individual inflator in question. Not including the original sample that necessitated the additional testing, evaluate as follows. Report each occurrence to the following to the appropriate Responsible Vehicl
26、e Engineering Organizations: a) With a minimum of fifteen (15) inflators a mean curve and variability limits specific to the (15) fifteen inflators in question shall be calculated. SAE/USCAR-24 REVISION 2 Revised 2013-04 USCAR INFLATOR TECHNICAL REQUIREMENTS AND VALIDATION - 21 - b) The mean of the
27、lot in question shall not deviate from the original program acceptance mean by greater than 33% of the original acceptance gate width (or height) in the appropriate axis (time or pressure) of each gates. c) Using the mean curve and a 3 as calculated from the fifteen (15) (or greater number of inflat
28、ors) from the lot in question, the 3 shall fall within the variability windows as determined from Table 3.2.7.A, Inflator Variability Limits, and Table 3.2.7.B, Ballistic Variability Limits using those specific (15) fifteen (or greater number of) inflators. 5. Based on program specific vehicle perfo
29、rmance requirements the Responsible Vehicle Engineering Organizations may alter the program specific closed tank test tolerances to narrower or broader windows to meet their program needs. TABLE 3.2.7.A - INFLATOR VARIABILITY LIMITS Inflator Variability Parameters (for Closed Tank Tests) 3 Standard
30、Deviation and TTFG Attribute Limits Slope using the best fit line along the curve as calculated from a minimum of 9 equally spaced points from 10%-50% pressure Nominal 12.5% (To be reported as Reference only) Time to First Gas (TTFG) (attribute based only) TTFG Passenger 5ms 7ms Driver Ambient 4ms C
31、old 6ms Side 2ms 4ms Time at P=10% of peak T10% of peak t(10%of peak) (30%*t(10%of peak) ) i.e . T10 (0.3* T10) Time at P=25% of peak T25% of peak t(25%of peak) (20%*t(25%of peak) ) i.e . T25 (0.2* T25) *Pressure at P=50% of peak P50% of peak Nominal + 15% - 12.5% *Alternative T at P= 50% of peak T5
32、0% of peak t(50%of peak) (12.5%*t(50%of peak) ) i.e . T50 (0.125* T50) *Pressure at P=75% of peak P75% of peak Nominal 12.5% *Alternative T at P= 75% of peak T75% of peak t(75%of peak) (12.5%*t(75%of peak) ) i.e . T75 (0.125* T75) Time to 90% of peak pressure T90% of peak Nominal 12.5% *Alternative
33、P at T= 90% of peak P90% of peak P(90%of peak) (12.5%*P(90%of peak) ) i.e . P90 (0.125* P90) Peak pressure Pmax Nominal 10% *Evaluation of either P=50%, 75%and 90% or T at P=50% , 75% and 90% is allowed at the suppliers discretion (based on curve slope at P=50%, 75% and 90%) Only one attribute (P or
34、 T) at each percent is required to meet the criteria. The Responsible Vehicle Engineering Organizations shall have the option to waive the tolerance variability requirements if acceptable Module performance can be demonstrated across the full range of ballistic variability. The Responsible Vehicle E
35、ngineering Organizations shall be the final arbiter of acceptable inflator variability. SAE/USCAR-24 REVISION 2 Revised 2013-04 USCAR INFLATOR TECHNICAL REQUIREMENTS AND VALIDATION - 22 - TABLE 3.2.7.B - BALLISTIC VARIABILITY LIMITS 3.2.8 Propellant Stability: The Inflator Supplier shall supply test
36、 data showing that all propellants, gasses and pyrotechnic compounds contained within the inflator(s) will remain within the specified performance requirements per Section 3.2.7, Inflator Performance and Variability Limits for a minimum of a inflators target life of fifteen years. The inflator suppl
37、ier shall provide basic ESD, Friction and Shock data in the unaged and aged conditions of all propellants, gasses (if applicable) and pyrotechnic compounds contained within the inflator(s). These shall not substantially increase in sensitivity over the fifteen-year life of the inflator. With the exc
38、eption of Ammonium Nitrate containing propellants, this shall be demonstrated by the successful completion of the informational requirements of Appendix A, Pre-Source Qualification (QFS) or Bookshelving Requirements, Section IIIG a DV, and PV to this specification. Ammonium Nitrate containing propel
39、lants shall be required to undergo added stability evaluation for propellant strength and burn rate stability as agreed to by the Responsible Vehicle Engineering Organization. Pmax - 10 % Pmax -3 Pmax +3 Pmax + 10 % P r e s s u r e Time (msec) (30%)*t10% of peak Mean Baseline Trace for each temperat
40、ure (20%)*t25% of peak +15% and -12.5% at P50% of peak or use 12.5% of T50% of peak T75% or P75% of peak 12.5% TTFG T90% or P90% peak 12.5% SAE/USCAR-24 REVISION 2 Revised 2013-04 USCAR INFLATOR TECHNICAL REQUIREMENTS AND VALIDATION - 23 - 3.2.9 Hermeticity: For pyrotechnic inflators, hermeticity (l
41、eak) limits shall be defined by successful completion of an induced moisture margin study. An Induced Moisture Margin Study is defined as the purposeful introduction and equilibration of moisture into sealed inflators to determine the resulting degradation in inflator performance. The acceptable lim
42、it of maximum potential degradation in performance by induced moisture shall be less than or equal to 10% of the nominal baseline performance over the fifteen year life of the vehicle. The acceptable leak limit is calculated based on the following assumptions: 1. daily respiration of 33C, 80% RH air
43、 (Reference MIL STD 810), 2. differential pressure based on a diurnal temperature range of 38 C. (Reference MIL STD 810), 3. all water is retained (i.e. no water is expired on each cycle), 4. cycles (1 per day for 15 years), 5. instantaneous min to max temperature change, 6. hour duration at each co
44、ndition, 7. and a circular duct of the shortest possible length. The calculated leak rate shall allow less water intrusion into the inflator than is demonstrated by the Induced Moisture Margin Study to degrade the inflator performance by less than or equal to 10%. The leak rate limit shall be set at
45、 a maximum of the calculated requirement, or 1 X 10 -4 cc/atm sec., assuming 100% Helium (or equivalent), which ever is less. For stored gas inflators, hermeticity limits shall be defined by the combined fifteen year loss of less than 10% of the baseline nominal performance in a closed tank test whe
46、n taking into account, both an induced moisture margin studies for any pyrotechnics not inside the pressurized region, and the gas loss of the pressure vessel(s). The overall hermeticity limit shall be set at the resulting calculated value limiting the potential degradation of the inflator performan
47、ce over the 15 year vehicle life to less than or equal to 10%. 3.2.9.1 Leak Detection: All inflator(s) shall contain Helium or an equivalent substance which shall be detectable if a leak is present in the pressure vessel and pyrotechnic chamber per Section 5.2.3.1, Leak Test. Alternate procedures ar
48、e acceptable (i.e. bombing, etc.) where process reliability and sensitivity are demonstrated to the Responsible Vehicle Engineering Organization. 3.2.9.2 Pressurized Inflators: All stored gas pressure bearing components shall remain intact and shall not leak at a rate greater than that determined in
49、 Section 3.2.9, Hermeticity after exposure to pressure cycling per Section 5.2.4.10, Pressure Cycle Durability Test (pressurized inflation devices) and tested per Section 5.2.3.1, Leak Test. Temporary modifications to the inflator for test purposes (i.e. transducer ports, etc.), that do not affect the fundamental integri
