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F.8.7.1 All teams must include an Impact Attenuator Data (IAD) report as part of the SES.
F.8.7.2 Impact Attenuator Functional Requirements
These are not test requirements
a. Decelerates the vehicle at a rate not exceeding 20 g average and 40 g peak
b. Energy absorbed must meet or exceed 7350 J When:
Total mass of Vehicle is 300 kg
Impact velocity is 7.0 m/s
F.8.7.3 When using the standard Impact Attenuator, the IAD Report must meet the following:
a. Test data will not be submitted
b. All other requirements of this section must be included.
c. Photos of the actual attenuator must be included
d. Evidence that the Standard IA meets the design criteria provided in the Standard Impact Attenuator specification must be appended to the report. This may be a receipt or packing slip from the supplier.
F.8.7.4 The Impact Attenuator Data Report when NOT using the Standard Impact Attenuator must include:
a. Test data that proves that the Impact Attenuator Assembly meets the functional requirements
b. Calculations showing how the reported absorbed energy and decelerations have been derived.
c. A schematic of the test method.
d. Photos of the attenuator, annotated with the height of the attenuator before and after testing.
F.8.7.5 Impact Attenuator Test Setup
a. During any test, the Impact Attenuator must be attached to the Anti Intrusion Plate using the intended vehicle attachment method.
b. The Impact Attenuator Assembly must be attached to a structurally representative section of the intended chassis.
The test fixture must have equivalent strength and stiffness to a baseline front bulkhead.
A solid block of material in the shape of the front bulkhead is not “structurally representative”.
c. There must be 50 mm minimum clearance rearwards of the Anti Intrusion Plate to the test fixture.
d. No part of the Anti Intrusion Plate may permanently deflect more than 25 mm beyond the position of the Anti Intrusion Plate before the test.
The 25 mm spacing represents the front bulkhead support and insures that the plate does not intrude excessively into the cockpit.
a. Dynamic testing (sled, pendulum, drop tower, etc.) of the Impact Attenuator must be conducted at a dedicated test facility. This facility may be part of the University, but must be supervised by professional staff or the University faculty. Teams must not construct their own dynamic test apparatus.
b. Quasi-static testing may be performed by teams using their University’s facilities/equipment, but teams are advised to exercise due care when performing all tests.
F.8.7.7 Test Analysis
a. When using acceleration data from the dynamic test, the average deceleration must be calculated based on the raw unfiltered data.
b. If peaks above the 40 g limit are present in the data, a Channel Filter Class (CFC) 60 (100Hz) filter per SAE Recommended Practice J211 “Instrumentation for Impact Test”, or a 100 Hz, 3rd order, low pass Butterworth (-3dB at 100 Hz) filter may be applied.