1、 _ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising ther
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4、70 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J3095_201606 SURFACE VEHICLE RECOMMENDED PRACTICE J3095 JUN2016 Issued 2016-06 L
5、inear Impactor Calibration Procedure RATIONALE Linear impactor tests have been used for decades to create dynamic performance data of occupant protection materials and safety systems. This data is generally used for comparative purposes, to compute energy management capability, and as input to mathe
6、matical models and computer simulations. There are also examples of linear impact tests used for vehicle component certification such as the FMVSS 226 Ejection Mitigation test used by NHTSA. Linear impactor test result variability is a problem that can be traced to many sources. One source of variab
7、ility in the FMVSS 226 linear impactor test is associated with the characteristics of the impactor itself. A calibration procedure for the linear impactor is needed to reduce the variability associated with it. This document establishes a standard for linear impactor performance that will ensure a l
8、evel of test accuracy, repeatability, and reproducibility. No such standard exists today, resulting in a complete lack of these elements among the various laboratories and institutions that regularly utilize linear impact test methods. 1. SCOPE This recommended practice provides a procedure for meas
9、uring quantitatively the physical characteristics of linear impactors that are believed to effect impact test accuracy, repeatability, and reproducibility. Suggested values and tolerance are also provided for specific applications of linear impactor testing (i.e. Ejection Mitigation tests, Head form
10、 Impact tests, Body Block tests). Two functional groups of linear impactors are considered, those whose function is related primarily to displacement and those related to measuring acceleration or force. 1.1 Purpose The purpose of this SAE Recommended Practice is to establish sufficient calibration
11、of the linear impactor test device so that results of similar tests conducted at different facilities can be compared. The linear impactor test device can be one of several types, such as those used for FMVSS 226 and Euro NCAP upper leg impactor. 1.2 Objective The primary objective of this linear ca
12、libration test procedure is to reduce variability associated with the linear impactor test device between test facilities. SAE INTERNATIONAL J3095 JUN2016 Page 2 of 11 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein.
13、Unless otherwise specified, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. Evans, N.C., Leigh, M.J.,
14、 “FMVSS 226 Ejection Mitigation: A Review,” SAE Technical Paper 2013-01-0469, 2013, doi: 10.4271/2013-01-0469 Heading, M., Stein, D., Dix, J., “Effects of Headroom Friction to Ejection Mitigation Testing,” SAE Technical Paper 2014-01-0533, 2014, doi:10.4271/2014-01-0533. Sharma, M, et al, “Instrumen
15、t Panel Head Form Impact Test: Effects of Different Impactors Phase-In Reporting Requirements; Incorporation by Reference Federal Register, Vol. 78, No. 174, Part II, 49 CFR Part 571, Federal Motor Vehicle Safety Standards; Ejection Mitigation, Final Rule, September 9, 2013 FMVSS 226 Ejection Mitiga
16、tion FMVSS 203 Laboratory Test Procedure FMVSS 201 Laboratory Test Procedure SAE INTERNATIONAL J3095 JUN2016 Page 3 of 11 2.1.3 Other publications Bhattaharjee, S., Chaka, M., Elkins, W., foster, M., Panoff, S., Stiyer, M., “Linear Inverse and Pendulum Calibration Evaluation,” presented at Pedestria
17、n Protection Flex-Pli, 5thTR-RUCC, July 30, 2012. ECE Global Registry, Article 6 of the Agreement Concerning the Establishing of Global Technical Regulations for Wheeled Vehicles, Equipment and Parts Which Can Be Fitted and/or Be Used on Wheeled Vehicle, Addendum, Global technical regulation No.1 “D
18、oor Locks and Door Retention Components (ECE/TRANS/132 and Corr.1),” Geneva, June 25, 1998. ECE Global Registry, Article 6 of the Agreement Concerning the Establishing of Global Technical Regulations for Wheeled Vehicles, Equipment and Parts Which Can Be Fitted and/or Be Used on Wheeled Vehicle, Add
19、endum, Global technical regulation No.1 “Door Locks and Door Retention Components (ECE/TRANS/132 and Corr.1),” ECE/Trans/180/add.1, April 1, 2005. Ferguson, S., “FMVSS No. 226 Ejection Mitigation, Final Rule,” Presentation at the 2ndMeeting of the Pole Side Impact GTR, Brussels, Belgium, March 3-4,
20、2011. GTR No.9 Heidon Shinto Scientific Co., Ltd, Tribogear General Catalogue, 2015. http:/www.heidon.co.jp/ Kett Online Store: Products, Handheld Friction Analyzers Tribometers, May 15, 2015. Laboratory Safety Training Manual http:/www.mae.virginia.edu/NewMAE/wp-content/uploads/2010/12/Safety_Train
21、ing_Manual.pdf Liu Qi, Xia Yong, Zhou Qing, “Friction Effects in Pedestrian Headform Impacts with Engine Hoods,” Tsinghua Science and Technology, ISSN 1007-0214, 13/18 pp631-638, Vol 14, Number 5, October 2009. Microsys Brochure, “Ejection Mitigation (FMVSS 226) the impactor appliance is in the orie
22、ntation defined by the reference testing procedure relative to the article being tested. (See example in Figure 1). 3.11 Reference Velocity Impact velocity specified in the reference testing procedure. 3.12 Reference Mass Mass of impactor appliance previously specified by the reference testing proce
23、dure. SAE INTERNATIONAL J3095 JUN2016 Page 5 of 11Figure 1 - Example linear impactor setup 4. LINEAR IMPACTOR FACILITY 4.1 Linear Impactor Site, General The linear impactor test site should encompass sufficient area to provide accommodations for the linear impactor fixture, various photographic/vide
24、o equipment, and a protected observation area. 4.1.1 Allowances for precise positioning of photographic/video equipment should be made, both on-board and off board. 4.2 Linear Impactor A linear impactor facility suitable for testing of passenger cars, light trucks, and vans should have the character
25、istics listed as follows: Stabilized humidity of 40 30 percent Stabilized temperature of 20 4 C 4.3 Protective Measures Protective measures consistent with the example laboratory safety training manual in the reference section should be taken to ensure the safety of test personnel and observers. 5.
26、CALIBRATION PROCEDURES The procedure described below is a generalized procedure that can be applied to the range of linear impactor applications currently in use. The specific parameters associated with each application have been defined in Section 6. 5.1 Measurement of Radial Deflection and Frictio
27、n Characteristics The static force used in the following tests to measure radial deflection and friction force was determined through computer modeling to be a typical radial force on an impactor appliance during actual testing. The results of this testing can be used to approximate the energy absor
28、bed by friction as a percentage of the total kinetic energy intended for the test. 5.1.1 With the impactor in “setup” position, extend the impactor to Distance “C” (minimum available stroke) as described in Figure 3. SAE INTERNATIONAL J3095 JUN2016 Page 6 of 11 5.1.2 Push on center of the impactor a
29、ppliance in a direction parallel to the axis of motion, using a constant rate of 50.8 (10) mm per second (2.0 (0.5) inches per second), while using a suitable load cell to record the forces (N) needed start, and to maintain that motion over a stroke of at least 200 (+/-2) mm. Using a suitable data r
30、ecording system (with 100 Hz minimum sampling rate), record the maximum force needed to start motion in Table 1 as “F1(s)” in column (+Z), and record the nominal (average) force needed to maintain motion in Table 1 as “F1(d)” in column (+Z), and the standard deviation “F1(dev)” in column (+Z). Run a
31、 total of five tests (4 repeat tests) and record the data in Table 1. 5.1.3 Return the impactor to the extended position as in 5.1.1. 5.1.4 Measure the vertical distance between the bottom surface of the impactor appliance quasi and a fixed horizontal plane. 5.1.5 Hang a mass or 100 (1) kg from the
32、back face of the impactor appliance as shown in Figure 2. 5.1.6 Measure the vertical distance between the bottom surface of the impactor appliance quasi and a fixed horizontal plane. 5.1.7 Record the difference between 5.1.4 and 5.1.6 as “Radial Deflection” (D) in the (+Z) column of Table 1. 5.1.8 P
33、ush on center of the impactor appliance in a direction parallel to the axis of motion, using a constant rate of 50 (+/- 10) mm per second (2.0 (0.5) inches per second), while using a suitable load cell to record the forces (N) needed start, and to maintain that motion over a stroke of at least 200 (
34、2) mm. Using a suitable data recording system (with 100 Hz minimum sampling rate), record the maximum force needed to start motion in Table 1 as F1(s) in column (+Z), and record the nominal force needed to maintain motion in Table 1 as “F2(d)” in column (+Z), and the standard deviation F2(dev) in co
35、lumn (+Z). Run a total of five tests (4 repeat tests) and record the data in Table 1. 5.1.9 Remove the impactor from its base, rotate the entire device clockwise 90 degrees (looking at the back of the head-form), and re-secure it to the base (may need additional fixture). 5.1.10 Repeat steps 5.1.1 t
36、hrough 5.1.8 to obtain the +X direction radial deflection and friction data. 5.1.11 Remove the impactor from its base, rotate the entire device clockwise another 90 degrees (now 180 degrees from “setup”), and re-secure it to the base (may need additional fixture). 5.1.12 Repeat steps 5.1.1 through 5
37、.1.8 to obtain the - Z direction radial deflection and friction data. 5.1.13 Remove the impactor from its base, rotate the entire device clockwise another 90 degrees (now 270 degrees from setup position), and re-secure it to the base (may need additional fixture). 5.1.14 Repeat steps 5.1.1 through 5
38、.1.8 to obtain the -X direction radial deflection and friction data. SAE INTERNATIONAL J3095 JUN2016 Page 7 of 11Figure 2 - Mass application to linear impactor 5.2 Impact Velocity, Timing, and Excursion Measurement: 5.2.1 Perform calibration tests as needed to determine the setup parameters needed t
39、o achieve impact speeds of 16 km/h, 20 km/h, and 24 km/h (or speeds consistent with reference test procedure plus 25% for due diligence). Record impactor displacement data during these tests for determining stroke requirements (see below). 5.2.2 Determine the impactor stroke needed to obtain the imp
40、act speed of 16 km/h from the speed calibrations performed in 5.2.1. This distance will be referred to as Distance “A”. 5.2.3 With the impactor in the setup position and a suitable anvil provided, prepare a calibration pad as follows (see Figure 3): 5.2.3.1 Mount a suitable energy absorbing material
41、 (able to absorb full KE of the impactor) to the anvil such that it will be contacted by the impactor appliance at a stroke distance 400 mm past Distance “A” (per 5.2.2). The material should be of sufficient initial stiffness such that initial contact by the impactor can be determined by examining t
42、he impactor accelerometer data. If no such material is available, mount a contact switch that will accurately indicate the time at which the impactor appliance reaches that position. 5.2.3.2 Mount a wood splint (of sufficient strength and stiffness to create a discernable change in the impactor appl
43、iance acceleration data) to the anvil so it is supported only at its ends, and so that it will be contacted by the impactor appliance at a stroke distance 200 mm before impactor appliance contact with the energy absorber mounted per 5.2.3.1. As an alternative to the wood splint, a contact switch cou
44、ld be used to indicate when the impactor appliance reaches that position. This information is needed to determine the time interval between T=0 (signal to fire the impactor) and theoretical contact with the test article. This data also provides an independent means to verify the accuracy of the disp
45、lacement measurement particularly with impactor systems that rely on double integration of the acceleration to obtain displacement data (if the difference in computed displacement between time of contact with Plane “B” and time of contact with Plane “C” is 200 mm the system is accurate). SAE INTERNA
46、TIONAL J3095 JUN2016 Page 8 of 115.2.4 Conduct five (5) tests using this setup at this speed. Compute the appropriate responses and document the results in Table 2. 5.2.5 Repeat 5.2.3 through 5.2.4 for the 20 km/hr impact speed (may need to adjust Distance “A” for this velocity). 5.2.6 Repeat 5.2.3
47、through 5.2.4 for the 24 km/hr impact speed (may need to adjust Distance “A” for this velocity). Figure 3 - Impact velocity, timing, and excursion measurement setup 5.3 Impactor Positioning Accuracy If the positioning of the impactor is not infinitely adjustable within its vertical and lateral adjus
48、tment range, indicate the increment of adjustment in Table 2. 5.4 Impactor Mass Indicate the actual total moving mass of the linear impact and impactor appliance to the nearest 0.01 kg in Table 2. SAE INTERNATIONAL J3095 JUN2016 Page 9 of 11 Table 1 - Impactor Friction DataRun +X -X +Z -Z MaxRadial
49、Deflection D 1 0102030405010203040501020304050Table 2 - Impactor Performance DataTarget Speed Measured Data Units Run 1 Run 2 Run 3 Run 4 Run 5 Average Std. Deviation*Pressure kPa 0.00 0.00Max Velocity km/h 0.00 0.00Stroke at Max Velocity mm 0.00 0.00*Time at Max Velocity sec 0.00 0.00Velocity at 1st Contact km/h 0.00 0.00*Stroke at 1st Contact mm 0.00 0.00*Time at 1st Contact sec 0.00 0.00Velocity at 2nd Conta
