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2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2012 SAE International All rights reserved. No part of this pub
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4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2961_201201SURFACEVEHICLERECOMMENDEDPRACTICEJ2961 JAN2012 Issued 2012-01 Linear Imp
5、act Test for Passenger Airbag Modules Component Evaluation RATIONALEProvide a repeatable test methodology that can be used for evaluating the component performance of Passenger Airbag Modules.TABLE OF CONTENTS 1. OBJECTIVE 32. REFERENCES 32.1 Applicable Documents 32.1.1 SAE Publications . 33. DEFINI
6、TIONS . 34. GENERAL TEST REQUIREMENTS . 54.1 Test Facility . 54.2 Safety Requirements 54.3 Equipment List 55. EQUIPMENT SPECIFICATION 65.1 Linear Impactor . 65.2 Instrumentation . 75.3 Body Block 85.4 Anvil. 95.5 Test Fixture . 106. TEST EXECUTION . 106.1 Test Setup . 106.2 Camera Setup . 127. DATA
7、ACQUISITION 137.1 Data Acquisition System . 137.2 Data Processing 13SAE J2961 Issued JAN2012 Page 2 of 20 8. DATA REPORTING 148.1 Explanation of items in the “Results and Calculated Airbag Characteristics” section 158.1.1 “Measured Airbag Penetration” . 158.1.2 “Absorbed Energy prior to bottom out”
8、. 158.1.3 “Acceleration Elastic Slope” 158.1.4 “Acceleration Plastic Limit” 168.1.5 “Calculated versus Measured Energy Deviation” . 168.1.6 “Calculated versus Measured Displacement Deviation” . 168.1.7 “Calculated Plastic G versus Peak G Deviation” 168.2 Explanation of items in “Measurement Quality
9、Check” section 168.2.1 “Velocity deviation” 168.2.2 “Displacement deviation” 168.3 Other Information 169. NOTES 179.1 Marginal Indicia . 17APPENDIX A PRESSURE TRANSDUCER SELECTION . 18APPENDIX B PRESSURE TAP INSTALLATION GUIDELINES . 19FIGURE 1 COORDINATE SYSTEM USED IN THIS TEST PROCEDURE . 4FIGURE
10、 2 TEST ANVIL POSITIONING OPTIONS DEPENDING ON IMPACTOR ORIENTATION . 7FIGURE 3 BODY BLOCK DIMENSIONS . 9FIGURE 4 RECOMMENDED IP MOUNTING AND WINDSHIELD ADJUSTMENT CAPABILITY 10FIGURE 5 DETERMINATION OF THE ZERO DISPLACEMENT POINT FOR THE BODY BLOCK. 11FIGURE 6 RECOMMENDED HIGH SPEED CAMERA VIEWS .
11、12FIGURE 7 PRESSURE DATA PROCESSING TECHNIQUE 14FIGURE 8 EXAMPLE OF A TYPICAL TEST REPORT FORMAT . 15FIGURE B1 INTERNAL PRESSURE TUBE REQUIRED ON SOME MODULES 19FIGURE B2 EXTENSION TUBE ATTACHED DIRECTLY TO AIRBAG 20TABLE 1 PASSENGER AIRBAG MODULE CLASSIFICATION 3TABLE 2 SUMMARY OF MEASUREMENT UNITS
12、 USED IN THE PROCEDURE 4TABLE 3 DETERMINATION OF THE TRIGGER POINT FOR AIRBAG DEPLOYMENT BASEDON PASSENGER AIRBAG CLASSIFICATION 11TABLE A1 TYPICAL PRESSURE TRANSDUCER SPECIFICATIONS . 18SAE J2961 Issued JAN2012 Page 3 of 20 1. OBJECTIVE This SAE Recommended Practice describes a method to be used wh
13、en performing linear impact testing for the benchmarking of Passenger Airbag (PAB) modules. The results obtained from the linear impact tests will be used to verify design requirements and/ or specifications, and for other engineering purposes such as module performance comparisons, and/ or correlat
14、ion to CAE models. The objective of this testing is to obtain the loading and unloading elastic slopes and the plastic limit for the passenger airbag module. The purpose for this procedure is to describe recommended test methods to ensure, to the extent possible, reliable and reproducible test resul
15、ts. Performance limits or acceptance criteria are not established as they are typically defined based on specific vehicle design requirements and/or manufacturer specifications. It is intended to be a general procedure for repetitive testing and suggests only general guidelines for the safe conduct
16、of tests and reliable data correlation. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE Internat
17、ional, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.SAE J211-1 Instrumentation for Impact Test - Part 1 - Electronic Instrumentation SAE J211-2 Instrumentation for Impact Test - Part 2: Photographic Instrument
18、ation SAE J1538 Glossary of Automotive Inflatable Restraint Systems 3. DEFINITIONS 3.1 PAB SIZE CLASSIFICATION: For the purpose of this test procedure, PAB modules have been divided into four classes as shown in Table 1. The test method outlined in this SAE Recommended Practice applies to PAB module
19、s of Class III and Class IV. TABLE 1 - PASSENGER AIRBAG MODULE CLASSIFICATION CLASS I CLASS II CLASS III CLASS IV Bag Volume (L) V 40 40 110 Coverage Head Only Head test warning system (i.e., siren and/or light); and personal safety equipment (PSE) such as eye protection, gloves, hearing protection,
20、 respirators, and grounding straps, if required. Proper written safety procedures should be followed in accordance with standard ordinance and pyrotechnic industry practice. All applicable OSHA safety standards must be followed.4.3 Equipment List The equipment will typically consist of the following
21、 basic components: a. Mounting Fixture (Anvil) The physical structure to which the module is mounted for the test, and those portions of the actual vehicle that directly influence the applicable performance of the module or the outcome of the test. b. Body Block provides a loading surface for the PA
22、B module c. Linearly guided impactor propels the body block into the deployed PABd. Accelerometer to measure the acceleration characteristics of the body block e. Displacement measurement shall be recorded using a non-contact displacement sensor.f. Data Acquisition System - Records and displays test
23、 data, such as the internal bag and/or inflator pressure versus time results, and temperature versus time of the module components during conditioning, when applicable g. High-Speed Video Equipment h. Lighting System - Intensity matched to video specifications and desired capture rate. i. Deployment
24、 Source - Provides the proper stimulus to actuate the inflator j. Strobe Light - To denote time zero on high-speed video for use during analysis k. Pressure Transducer (optional) - Measures the pressures inside the bag and/or inflator SAE J2961 Issued JAN2012 Page 6 of 20 5. EQUIPMENT SPECIFICATION
25、5.1 Linear Impactor This test requires a linearly guided impactor that meets the following specifications: Must be able to propel the body at the required velocity (4.5 m/s, 6.7 m/s, and 7.7 m/s) within 0.1 m/s. Must be able to linearly guide the body block through its full stroke while allowing no
26、more than 10 mm deflection under a radial load of 50 kg, and with a coefficient of friction 0.3. (0.3 is standard for linear impact bearing material). Must have sufficient stroke to allow the impactor to have achieved the target impact speed prior to reaching the target trigger distance “Do” (per Ta
27、ble 2 in Section 6). Must contain some means for triggering the deployment of the PAB module when the body block is at distance “Do“ (per Table 2 in Section 6) within 5 mm away from first contact with the IP. Must include a rigidly constructed positioning system that can align the impactor laterally
28、 (Y-dimension) with the geometric center of the module opening, and parallel with the vehicles longitudinal centerline. Vertical and lateral positioning is described later in this specification. Maintain a gap of 40 mm (5 mm) between the anvils simulated windshield and the body block to ensure no co
29、ntact is made during the test and the air bag is not pinched between the body block and the wind-screen. Must be able to align impactor at a 15 degree (1 degree) downward with the anvil by either 1 rotating the impactor 15 degrees from the horizontal or 2 rotating the anvil. Both options are shown i
30、n Figure 2. SAE J2961 Issued JAN2012 Page 7 of 20 40 mm (s5mm)15 (s1 deg)ssOption 1Rotate Impactor 15ofrom the horizontal.40 mm (s5mm)15 (s1)Option 2Rotate Anvil 15ofrom the horizontal.FIGURE 2 - TEST ANVIL POSITIONING OPTIONS DEPENDING ON IMPACTOR ORIENTATION In cases where the PAB interacts with t
31、he occupant lap during deployment a means of simulating the occupant lap should be provided. The material used should be such that it can be pushed out of the way with minimal force so that it will not affect the energy absorption characteristic of the PAB measured in the test. 5.2 Instrumentation D
32、isplacement measurement shall be recorded using a non-contact displacement sensor with an accuracy of at least 1.0 mm (one example is to utilize an IES Model 2098 (belt motion sensor). Displacement measurement shall be defined as “gap” measurement where zero (0) gap is contact with the I.P. Accelera
33、tion measurements to be made in accordance with SAE J211/1 or ISO 6487. Accelerometers should be rated for 500 to 2000 g peak acceleration. SAE J2961 Issued JAN2012 Page 8 of 20 A pressure transducer may be utilized to measure pressure inside the airbag. Recommended pressure transducer specification
34、s are provided in Appendix A. All transducers, instrumentation, and data filters (analog and digital) shall be selected per SAE J211. o The pressure transducer and “extension tube,” when used, should be mounted in a location clear from the unfolding bag, with the pressure inlet located in an area of
35、 reduced gas flow within the module to minimize the “Venturi” effect on the measured pressure. Caution must be observed during interpretation of all module pressure data due to the dynamic variation of pressure during cover opening and bag fill. Guidelines for installing pressure taps in the various
36、 airbag module configurations are provided in Appendix B. o Where practicable, pressure transducers used for comparison testing should be standardized. Results from different transducer types or models may vary significantlyespecially when measuring short duration pressure pulses such as those produ
37、ced during airbag deployment door break-out. The break-out pressure reading will also be affected by pick-up tube diameter, length, and material variations. Longer and/or more flexible tubes will have a damping effect on the data similar to filtering. o The dynamic range of the pressure transducer m
38、ust be compatible with the temperature and pressure expected from the test. A means of calibrating the pressure transducers prior to testing shall be provided. Pressure transducer calibrations shall be conducted regularly and calibration results recorded. Refer to the transducer manufacturers recomm
39、ended procedure for calibrations. See Appendix A for recommended performance specifications. 5.3 Body Block Total guided mass: 35 kg 0.1 kg. Dimensions (Figure 3): The airbag interface surface shape is defined below (dimensions in mm), with the torso contact surface defined by the flat surface 250 m
40、m wide x 700 mm tall. Debur and break all sharp edges and corners. Reinforce and ballast as needed to attach it to the impactor guide system, achieve desired mass, and keep it from deforming during these impact tests, or as result of contact with a rigid instrument panel fixture. To control friction
41、 between the airbag and body block, cover impactor contact surface with black 2 in Gaffer tape (one example is Shurtape model 2 inch P/N PC-628). Overlapping each row of tape 10 mm (3 mm). SAE J2961 Issued JAN2012 Page 9 of 20 FIGURE 3 - BODY BLOCK DIMENSIONS 5.4 Anvil The IP mounting surface must b
42、e capable of adjustment in the vertical, lateral, and/or longitudinal direction, as necessary, to achieve the necessary relationship between the impactor and the IP (Figure 4). The windshield plate angle must be adjustable to simulate the angle of the vehicle in the subject vehicle. Rigidly construc
43、ted shall have a minimum 500 Hz first mode natural frequency to ensure that the vibration of the fixture does not affect the data up to 100 Hz. SAE J2961 Issued JAN2012 Page 10 of 20 FIGURE 4 - RECOMMENDED IP MOUNTING AND WINDSHIELD ADJUSTMENT CAPABILITY 5.5 Test Fixture The IP fixture shall be moun
44、ted to the Anvil such that the position and orientation of the module relative to the simulated windshield is accommodated. Two options can be used for representing the IP: 1. A I.P. from the subject vehicle can be used. The I.P. and supporting structure shall be rigidly attached to the anvil to pro
45、perly support the PAB module. 2. A generic I.P. fixture can be used which simulates the subject vehicles I.P. surface with the P.A.B. mounting structure.6. TEST EXECUTION 6.1 Test Setup Fabricate the module mounting fixture to properly locate/orient the module within the generic IP fixture Set PAB t
46、o Windshield vertical distance (Figure 5), from center of airbag opening to windshield, to match that of the subject vehicle. Set the Windshield angle to match that of the subject vehicle. At Contact with the IP, establish 40 mm minimum gap between the anvil and the Body Block (Figure 5). Contact wi
47、th the IP is 0 mm (“Point of Origin” in Figure 5). Determine the starting distance of the Body Block to the IP (“Do” distance + free stroke distance + stroke needed to attain the impact speed per Figure 5 and Table 3).SAE J2961 Issued JAN2012 Page 11 of 20 “Do” = Body Block-to-IP Distance at PAB T=0
48、 (trigger distance) 40 5 mm Cushion Depth (mm) Vertical Distance (mm) Point of Origin15oFIGURE 5 - DETERMINATION OF THE ZERO DISPLACEMENT POINT FOR THE BODY BLOCK TABLE 3 - DETERMINATION OF THE TRIGGER POINT FOR AIRBAG DEPLOYMENT BASED ON PASSENGER AIRBAG CLASSIFICATION CLASS III CLASS IV Bag Volume
49、 (L) 80 110 Coverage Head & Thorax (belted) Head & Thorax (unbelted) Trigger Distance “Do” 530 mm (+45/-0 mm)* 575 mm (+45/-0 mm)* Body Block Mass (kg) 35 35 * The target distance for Doshould be used whenever possible. The Doused can be increased up to 45 mm if needed to avoid excessive premature PAB engagement. The value used for Domust
