ISO 22074-8:2022 pdf download – Railway infrastructure — Rail fastening systems — Part 8: Test method for vertical stiffness.
6 Test procedures for pads 6.1 Static test procedure for pads 6.1.1 Principle A force is applied normal to the test pad and the displacement is measured. 6.1.2 Apparatus 6.1.2.1 Controlled temperature test area, area of the laboratory where the test is conducted, maintained at (25 ± 5) °C. Where pads are to be used at other ambient temperatures, additional tests shall be performed in a temperature-controlled chamber, if required by the purchaser, at one or more of the following temperatures: (−30 ± 3) °C, (−20 ± 3) °C, (−10 ± 3) °C, (0 ± 3) °C and (50 ± 3) °C. Additional test temperatures may be agreed between the manufacturer and the purchaser. 6.1.2.2 Metal plate, rigid, larger than the load distribution plate. 6.1.2.3 Load distribution plate, rectangular upper load distribution, made from metal 10 mm minimum thickness, with smooth, rounded edges, such that the load distribution plate does not damage the pad under test. The dimensions of the plate depend on the type of pad being tested as follows: — Rail pads: the same width as the foot of the rail used for the repeated loading test (see ISO 22074-4) and a length of 210 mm. Alternatively, a short length of rail, at least 210 mm long, may be used instead of the upper load distribution plate and upper metal plate. — Baseplate pads: the same width and length as the maximum rectangular area within the part of the baseplate transmitting the load to the pad in the fastening assembly. When the pad is supported in use over a limited area, a lower load distribution plate, of the same dimensions as the part of the pad which would be actively supported in the fastening assembly, is also required. NOTE 1 For tests on continuous pads used in slab track a length of pad of 150 mm is used. NOTE 2 If the metal plate described in 6.1.2.2 matches the size of the upper load distribution plate, the load distribution plate can be omitted. 6.1.2.4 Abrasive cloth, with grit size P120 to P400 (ISO 6344-1) in unworn condition, the dimensions of each sheet being not less than the full area of the pad to be tested. 6.1.2.5 Actuator capable of applying a force of (F SPmax + 10 %) kN through a spherical seating. NOTE Typically, the maximum force is 120 kN.
6.1.2.6 Displacement-measuring instruments
a) If contacting displacement-measuring instruments are used, they shall conform with ISO 9513.
b) If non-contacting displacement-measuring instruments are used, they shall be calibrated to ensure that they can measure the displacement of the metal plate relative to the base as required in 6.1.3.
ISO 22074-8:2022 pdf download – Railway infrastructure — Rail fastening systems — Part 8: Test method for vertical stiffness
