AS ISO 3449:2020 pdf free.Earth-moving machinery – Falling-object protective structures – Laboratory tests and performance requirements.
5.1.2 Test facility apparatus that provides a means to
a) raise the test object to the required height,
b) release it so that it drops without restraint, and
c) determine whether the FOPS enters the deflection-limiting volume (DLV) during the test.
The means of determining c) may be either 5.1.3 or 5.1.4.
5.1.3 DLV structure, placed upright and made of a material that will indicate any penetration by the FOPS — grease or other suitable material being permitted to be put on the lower surface of the FOPS cover to indicate such penetration.
The DLV structure and its location shall be in accordance with ISO 3164. The DLV structure shall be fixed firmly to the same part of the machine as the operator’s seat and shall remain there during the entire formal test period.
5.1.4 Suitable dynamic instrumentation system, with a dynamic measurement accuracy of ± 5 %, for measuring the expected deflection of the FOPS with respect to the DLV.
5.2 Test conditions
5.2.1 Test bed
The FOPS to be evaluated shall be attached to the machine structure, as it would be in actual machine use. Although a complete machine is not required, the portion on which the FOPS is mounted shall be identical to the actual structure, and the vertical stiffness of the test bed shall be not less than that of an actual machine according to 5.2.2.
5.2.2 Machine-mounted FOPS
For FOPS mounted on a machine:
— the machine may be provided with equipment or attachments as specified by the manufacturer;
— all ground-engaging tools shall be in the normal transport position;
— all suspension systems, including pneumatic tyres, shall be set at operating levels, and variable suspensions shall be in the “maximum stiffness” range;
— all cab elements, such as windows, normally removable panels or non-structural fittings, shall be removed so that they do not contribute to the strength of the FOPS.
5.3 Test procedure
5.3.1 FOPS
The test procedure shall be performed as follows, in the sequence given.
a) Place the test object on top of the FOPS, with the small end downwards for level II, at the impact location. The impact location shall touch, or be within the vertical projection of, the uppermost plane area of the DLV, as specified in the following three cases and shown in Figure 3. Major FOPS structural members that have a significant effect on FOPS deformation need to be considered according to each of these cases.
1) Where major, upper, horizontal members of the FOPS do not enter the vertical projection of the DLV on the FOPS top, select the test object impact location so as to produce the greatest deformation towards the uppermost horizontal plane of the DLV and be as close to the centroid of the FOPS structure as possible. See Figure 3 a).
2) Where major, upper, horizontal members of the FOPS do enter the vertical projection of the DLV on the FOPS upper structural member, and the covering material of all the surface areas above the DLV is the same and of uniform thickness, select the test object impact location so as to produce the greatest deformation over, partially over, or tangent with, the uppermost horizontal plane of the DLV (depending on structure), with the least possible distance from the centroid, and outside the area of any upper structural member of the FOPS. See Figure 3 b).
3) Where different materials or a different thickness are used in different areas above the DLV, subject each area to an impact test. Select the test object impact location for each area so as to produce the greatest deformation over, partially over, or tangent with, the uppermost horizontal plane of the DLV, with the least possible distance from the centroid, but outside the area of any upper structural members of the FOPS. If cut-outs in the FOPS cover are intended to be filled with devices or equipment to provide adequate protection, those devices or equipment shall be in place during the test. See Figure 3 c).
b) Raise the test object vertically to a height above the position indicated in a) of this subclause to develop energy in accordance with Clause 4 a) or b), depending on the type of FOPS being tested.
c) Release the test object so that it falls without restraint onto the FOPS.
As it is unlikely that the free fall will result in the test object hitting at the exact location and/or in the attitude according to a), the following limits are placed on deviations.
— For a level II FOPS, the initial impact of the small end of the test object shall be entirely within a circle of 200 mm radius whose centre coincides with the vertical centre line of the test object as positioned according to a).
— For a level I FOPS, the impact of the test sphere shall be entirely within a circle of 100 mm radius whose centre coincides with the vertical centre-line of the test object as positioned according to a).
— For the level II FOPS test, the first contact between the test object and the FOPS shall only be along the small end and/or the radius contiguous to that end (see Figure 2).
There is no limitation on location or attitude of subsequent impacts due to rebound.
5.3.2 Integral FOPS/ROPS
For integral FOPS/ROPS, if the same structure is used for the evaluation of both, the FOPS test according to 5.3.1 shall precede the ROPS test (see ISO 3471). The removal of impact dents or replacement of the FOPS cover is permitted.AS ISO 3449 pdf download.