ANNEX

CONTENTS
PART II
CHAPTER III

Upper legform to bumper tests
1.

Scope
This test procedure is applicable to requirements under both Section 3.1 and Section 3.2 of Annex I of the Directive 2003/102/EC.
2.

General
2.1.
The upper legform impactor for the bumper test shall be mounted to the propulsion system, by a torque limiting joint, to prevent large off centre loads damaging the guidance system. The guidance system shall be fitted with low friction guides, insensitive to off-axis loading, that allow the impactor to move only in the specified direction of impact, when in contact with the vehicle. The guides shall prevent motion in other directions including rotation about any axis.
2.2.
The impactor may be propelled by an air, spring or hydraulic gun, or by other means that can be shown to give the same result.
3.

Specification of the test
3.1.
The purpose of the test is to ensure that the requirements given in paragraphs 3.1.1.2 and 3.2.1.2 of Annex I of the Directive 2003/102/EC are fulfilled.
3.2.
Upper legform to bumper tests shall be carried out to test positions selected in paragraph 3.2, Chapter II of this Part, if the lower bumper height at the test position is more than 500 mm and the manufacturer elects to perform an upper legform test instead of a lower legform test. In exceptional cases, and only with regard to the test procedure applicable under point 3.1.1.2 of Annex I of the Directive, manufacturers may apply for a derogation concerning the application of this alternative test to vehicles with a lower bumper height of less that 500 mm.
3.3.
Manufacturers may apply for derogation concerning an exemption zone for a removable towing hook.
3.4.

Test method
3.4.1.

Test apparatus
3.4.1.1.
The upper legform impactor shall be rigid, foam covered at the impact side, and 350 ± 5 mm long and comply with Section 4 of this Chapter and Figure 4a of this Part.
3.4.1.2.
Two load transducers shall be fitted to measure individually the forces applied at either end of the upper legform impactor, plus strain gauges measuring bending moments at the centre of the upper legform impactor and at positions 50 mm either side of the centre line, see Figure 4a.
3.4.1.3.
The instrumentation response value CFC, as defined in ISO 6487:2000, shall be 180 for all transducers. The CAC response values, as defined in ISO 6487:2000, shall be 10 kN for the force transducers and 1 000 Nm for the bending moment measurements.
3.4.1.4.
The upper legform impactor shall meet the performance requirements specified in Section 3 of Appendix I, and shall be fitted with foam cut from the sheet of material used for the dynamic certification test. The certified impactor may be used for a maximum of 20 impacts before re-certification (this limit does not apply to propulsion or guidance components). The impactor shall also be re-certified if more than one year has elapsed since the previous certification or if any impactor transducer output, in any impact, has exceeded the specified CAC.
3.4.1.5.
The upper legform impactor shall be mounted and propelled as specified in points 2.1 and 2.2.
3.4.2.

Test procedure
3.4.2.1.
The state of the vehicle or sub-system shall comply with the requirements of Chapter I of this Part. The stabilised temperature of the test apparatus and the vehicle or sub-system shall be 20 °C ± 4 °C.
3.4.2.2.
Tests shall be made to the bumper between the corners to locations defined in paragraph 3.2.
3.4.2.3.
The direction of impact shall be parallel to the longitudinal axis of the vehicle, with the axis of the upper legform vertical at the time of first contact. The tolerance to these directions is ± 2°. At the time of first contact the impactor centre line shall be midway between the upper bumper reference line and the lower bumper reference line with a ± 10 mm tolerance and laterally with the selected impact location with a tolerance of ± 10 mm.
3.4.2.4.
The impact velocity of the upper legform impactor when striking the bumper shall be 11,1 ± 0,2 m/s.
4.

Upper legform impactor
4.1.
The total mass of the upper legform impactor including those propulsion and guidance components which are effectively part of the impactor during the impact shall be 9,5 kg ± 0,1 kg. The upper legform impactor mass may be adjusted from this value by up to ± 1 kg, provided the required impact velocity is also changed using the formula:
V = sqrt((1 170)/M)
where
V
- impact velocity (m/s)
M
- mass (kg), measured to an accuracy of better than ± 1 %
4.2.
The total mass of the front member and other components in front of the load transducer assemblies, together with those parts of the load transducer assemblies in front of the active elements, but excluding the foam and skin, shall be 1,95 ± 0,05 kg.
4.3.
The foam shall be two sheets of 25 mm thick Confor TM foam type CF-45. The skin shall be a 1,5 mm thick fibre reinforced rubber sheet. The foam and rubber skin together shall weigh 0,6 ± 0,1 kg (this excludes any reinforcement, mountings, etc. which are used to attach the rear edges of the rubber skin to the rear member). The foam and rubber skin shall be folded back towards the rear, with the rubber skin attached via spacers to the rear member so that the sides of the rubber skin are held parallel. The foam shall be of such a size and shape that an adequate gap is maintained between the foam and components behind the front member, to avoid significant load paths between the foam and these components.
4.4.
The front member shall be strain gauged to measure bending moments in three positions, as shown in Figure 4a, each using a separate channel. The strain gauges are located on the impactor on the back of the front member. The two outer strain gauges are located 50 ± 1 mm from the impactor's symmetrical axis. The middle strain gauge is located on the symmetrical axis with a ± 1 mm tolerance.
4.5.
The torque limiting joint shall be set so that the longitudinal axis of the front member is perpendicular to the axis of the guidance system, with a tolerance of ± 2°, with the joint friction torque set to a minimum of 650 Nm.
4.6.
The centre of gravity of those parts of the impactor which are effectively forward of the torque limiting joint, including any weights fitted, shall lie on the longitudinal centre line of the impactor, with a tolerance of ± 10 mm.
4.7.
The length between the load transducer centre lines shall be 310 ± 1 mm and the front member diameter shall be 50 ± 1 mm.
Figure 4a

Upper legform impactor