SAE J972 pdf download
SAE J972 pdf download.Moving Rigid Barrier Collision Tests.
1. Collision tests are conducted on automotive vehicles to obtain infomiation of value in evaluation of structural integrity and in reducing the lisk of occupant injuries. The deformation resulting from a moving rigid barrier impact is more severe at a given speed than that produced by using an actual vehicle, but is more readily reproducible than that occurring during vehicle to vehicle impacts. The purpose of this SAE Recommended Practice is to establish sufficlent standardization of such moving barriers and moving barrier collision methods so that results of tests conducted at different facilities may be compared,
2. References
21 Applicable Publications—The following publications form a part of the specification to the extent specified herein. Unless otherwise indicated the latest revision of SA publications shall apply.
2.1.1 SAE PUBLICATION—Available from SAE. 400 Commonwealth Drive, Warrendale, PA 15096-0001.
SAE J21 1 -1—Instrumentation for Impact Tests—Part 1: Electronic Instrumentation
SAE J21 1 -2—Instrumentation for Impact Tests—Part 1: Photographic Instrumentation
2.1.2 FMVSS PUWCATI0N—Available from the Superintendent of Documents, U. S. Government Printing Office, Mail Stop: SSOP. Washington. DC 20402-9320.
FMVSS 301
3. ObjectIves—The primary obec1ive of this document is to detine test procedures for impacts which will result in a simulation of forces and deformations experienced during a vehicle crash. Standardized procedures allow evaluation of vehicle structural loads and deflections, occupant loads and dynamics, photographic, video, and post-collision observations of pertinent areas or events which are useful in establishing design crileria,
4. Crash Test Facility
4.1 Test Site, General—The test site shall be of sufficient area to provide accommodations for the test vehicle, various photographic equipment, a protected observer area, and provisions for accelerating the moving barrier to the desired velocity.
4.1.1 The Immediate crash sde shall be level.
4.1.2 The approach road and the surface at the immediate crash site shall be paved.
4.1.3 Allowances for proper positioning of photographic equipment should be made.
4.1.4 Allowances should be made for post impact motion of both the test vehicle and the moving barrier.
4.1.5 Document guide ra andior steering inputs and location and direction of application.
4.2 Approach—The type of approach required depends upon the technique employed to obtain the desired impact velocity of the moving barrier. A practical approach is level, straight, and of sufficient length to permit the moving barrier to be towed along a rail guidance system with the impacts occurring after the moving barrier is released from me tow force and released from guidance at the end of the rail.
4.3 Barrier—Two rigid impact surfaces are used: the flat surface described in 4.3.2 for rear and side impact tests and the contoured surface described in 4.3.3. generally used for school bus testing. These two surfaces are attachable to the front end of a common carriage as shown In Figure 1.
4.3.1.2 The total mass shall be 1814 kg ± 23kg. The mass distribution shall be: front axle, 55% t 10%, and rear axle, 45% ± 10% g 407 kg ± 10 kg at each rear wheel and 500 kg ± 10kg at each front wheel.
4.3.1.3 II shall have a braking device capable 01 stopping It.
4.3.1.4 Track width of 1524 mm ± 30 mm. front and rear axles.
4.3.1,5 Wheel base of 3048mm ± 50mm.
• 43.1.6 Pneumatic tires on all wheels, P205-75 Ri 5, or equivalent, inflated to 207 kPa.
4.3.1.7 The center of gravity shall be located at:
X = 1372 mm ± 40 mm rearward of the front wheel axis
V — at the longitudinal-vertical plane of symmetry ±5 mm
Z — 401 mm ± 13 mm above ground
4.3.2 REAR AND SIDE IMPAcT TESTiNG—The impact surface of the barrier is a vertical rigid flat rectangle 1524 mm high and 1981 mm wide with its lower edge horizontal and 127 mm ± 13 mm from the ground. The impact surface is covered with 19 mm thick plywood.
4.3.3 CONTOURED MOVING BARRIER IMPACT TESTING—A contoured impact surface 629 mm high and 1981 mm wide shall be attached to the carriage as shown in Figure 2. The impact surface Is not covered with plywood. Ground clearance to the lower edge of the impact surface shall be 133 mm ± 13 mm. The contoured moving barrier assembly shall have a moment of inertia about the center of gravity as follows:
5. Methodology
5.1 General—Even when simplified by using moving barriers, vehicle collisions are very complex and careful controls of impact parameters must be exercised. Paragraphs 5.1.1, 5.1.2, 5.1.3, 5.1.4. arid 5.1.5 shall be followed for every moving barrier test, with the addition of those in 5.2 or 5.3 for the specific type of test under consideration.
5.1.1 The moving barrier shall impact the test vehicle while moving at essentially a constant velocity. The impact velocity chosen will depend upon the object of the test or the specific energy levels desired.
5.1.2 The moving barrier shall be braked within 5 ms following an initial separation from the impacted vehicle to preclude subsequent impacts.
5.1.3 The test vehicle shall be stationary with its parking brake off and the transmission in neutral.
5.1.4 All doors on the test vehicle shall be closed and locked.
5.1.5 Position of windows during test will be contingent on test objectives.
