ANNEX

CONTENTS
PART II
CHAPTER II

Lower 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 lower legform impactor for the bumper tests shall be in ‘free flight’ at the moment of impact. The impactor shall be released to free flight at such a distance from the vehicle that the test results are not influenced by contact of the impactor with the propulsion system during rebound of the impactor.
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 3.1.1.1 and 3.2.1.1 of Annex I of the Directive 2003/102/EC are fulfilled.
3.2.
A minimum of three lower legform to bumper tests shall be carried out, one each to the middle and the outer thirds of the bumper at positions judged to be the most likely to cause injury. Tests shall be to different types of structure, where they vary throughout the area to be assessed. The selected test points shall be a minimum of 132 mm apart, and a minimum of 66 mm inside the defined corners of the bumper. These minimum distances are to be set with a flexible tape held tautly along the outer surface of the vehicle. The positions tested by the laboratories shall be indicated in the test report.
3.3.
Manufacturers might 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 lower legform impactor shall consist of two foam covered rigid segments, representing femur (upper leg) and tibia (lower leg), joined by a deformable, simulated knee joint. The overall length of the impactor shall be 926 ± 5 mm, having a required test mass of 13,4 ± 0,2 kg and comply with Section 4 of this Chapter and Figure 1 of this Part. Brackets, pulleys, etc. attached to the impactor for the purpose of launching it, may extend the dimensions shown in Figure 1.
3.4.1.2.
Transducers shall be fitted to measure knee bending angle and knee shearing displacement. One uni-axial accelerometer shall be fitted to the non-impacted side of the tibia, close to the knee joint, with its sensitive axis in the impact direction.
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 50° for the knee bending angle, 10 mm for the shearing displacement and 500 g for the acceleration. This does not require that the impactor itself be able to physically bend and shear to these angles and displacements.
3.4.1.4.
The impactor shall meet the performance requirements specified in Section 2 of Appendix I, and shall be fitted with deformable knee elements from the same batch as those used in the certification tests. The impactor shall also be fitted with foam cut from one of up to four consecutive sheets of Confor™ foam flesh material produced from the same batch of manufacture (cut from one block or bun of foam), provided that foam from one of these sheets was used in the dynamic certification test and the individual weights of these sheets are within ± 2 % of the weight of the sheet used in the certification test. The certified impactor may be used for a maximum of 20 impacts before re-certification. With each test new plastically deformable knee elements should be used. 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 impactor shall be mounted, propelled and released as defined in paragraphs 2.1 and 2.2.
3.4.2.

Test procedure
3.4.2.1.
The state of the vehicle or subsystem shall comply with the requirements of Chapter I of this Part. The stabilised temperature of the test apparatus and the vehicle or subsystem shall be 20 °C ± 4 °C.
3.4.2.2.
Tests shall be made to the bumper between the corners to locations defined in point 3.2.
3.4.2.3.
The direction of the impact velocity vector shall be in the horizontal plane and parallel to the longitudinal vertical plane of the vehicle. The tolerance for the direction of the velocity vector in the horizontal plane and in the longitudinal plane shall be ± 2° at the time of first contact.
The axis of the impactor shall be perpendicular to the horizontal plane with a tolerance of ± 2° in the lateral and longitudinal plane. The horizontal, longitudinal and lateral planes are orthogonal to each other (see Figure 3).
3.4.2.4.
The bottom of the impactor shall be at ground reference level at the time of first contact with the bumper (see Figure 2), with a ± 10 mm tolerance.
When setting the height of the propulsion system, an allowance must be made for the influence of gravity during the period of free flight of the impactor.
At the time of first contact the impactor shall have the intended orientation about its vertical axis, for the correct operation of its knee joint, with a tolerance of ± 5° (see Figure 3).
3.4.2.5.
At the time of first contact the centre line of the impactor shall be within a ± 10 mm tolerance to the selected impact location.
3.4.2.6.
During contact between the impactor and the vehicle, the impactor shall not contact the ground or any object which is not part of the vehicle.
3.4.2.7.
The impact velocity of the impactor when striking the bumper shall be 11,1 ± 0,2 m/s. The effect of gravity shall be taken into account when the impact velocity is obtained from measurements taken before the time of first contact.
4.

Lower Legform impactor
4.1.
The diameter of the femur and tibia shall be 70 ± 1 mm and both shall be covered by foam ‘flesh’ and skin. The foam flesh shall be 25 mm thick Confor™ foam type CF-45. The skin shall be made of neoprene foam, faced with ½ mm thick nylon cloth both sides, with an overall thickness of 6 mm.
4.2.
The ‘centre of the knee’ is defined as the point about which the knee effectively bends.
The ‘femur’ is defined as all components or parts of components (including flesh, skin covering, damper, instrumentation and brackets, pulleys, etc. attached to the impactor for the purpose of launching it) above the level of the centre of the knee.
The ‘tibia’ is defined as all components or parts of components (including flesh, skin covering, instrumentation and brackets, pulleys, etc. attached to the impactor for the purpose of launching it) below the level of the centre of the knee. Note that the tibia as defined includes allowances for the mass etc. of the foot.
4.3.
The total mass of the femur and tibia shall be 8,6 ± 0,1 kg and 4,8 ± 0,1 kg respectively, and the total mass of the impactor shall be 13,4 ± 0,2 kg.
The centre of gravity of the femur and tibia shall be 217 ± 10 mm and 233 ± 10 mm from the centre of the knee respectively.
The moment of inertia of the femur and tibia, about a horizontal axis through the respective centre of gravity and perpendicular to the direction of impact, shall be 0,127 ± 0,010 kg/m2 and 0,120 ± 0,010 kg/m2 respectively.
4.4.
A uniaxial accelerometer shall be mounted on the non-impacted side of the tibia, 66 ± 5 mm below the knee joint centre, with its sensitive axis in the direction of impact.
4.5.
The impactor shall be instrumented to measure the bending angle and the shearing displacement between femur and tibia.
4.6.
A damper shall be fitted to the shear displacement system and may be mounted at any point on the rear face of the impactor or internally. The damper properties shall be such that the impactor meets both the static and dynamic shear displacement requirements and prevents excessive vibrations of the shear displacement system.
Figure 1

Lower legform impactor with skin and foam covering
Figure 2

Lower legform to bumper tests for complete vehicle in normal ride attitude (left) and for complete vehicle or sub-system mounted on supports (right)
Figure 3

Tolerances of angles for the lower legform impactor at the time of first impact