TB/T 3396.2-2015 Test methods for fastening systems of high-speed railway - Part 2: Determination for clamping force
1 Scope
This part specifies the indoor test method for fastener clamping force. This part is applicable to high-speed railway fastener systems.
2 Symbol
For the purposes of this document, the following symbols apply.
d—— Vertical displacement of the sleeper relative to the rail, in mm;
ms—— Mass of the sleeper or part of the sleeper used in the test and the fasteners assembled on it, kg;
mf—— Mass of the loading rig supported by the sleeper, kg;
P—— Vertical force acting on the rail or sleeper, kN;
P0—— Vertical force at zero displacement of the rail just when the buckle pressure is counteracted, kN;
P1—— Vertical force acting on the rail or sleeper when unloaded until the average reading of the displacement sensor is zero, kN.
3 Principle
The fastener clamping force is determined by measuring the force that disengages the rail from the rail bearing surface.
4 Test equipment
4.1 Steel rail
A short segment of rail with a length of about 0.5 m is used; its cross section is the same to that of the rail used for the assembly or assembly fatigue performance test of the fastener to be tested. The rail shall be free of peeling and floating rust on the surface.
4.2 Loading device
The loading device can apply a static vertical load of 50 kN at a loading rate of 9kN/min ~ 11 kN/min. For the benchmark test method, the load is applied to the rail; for the alternative test method, the load is applied to the loading rig supported on the sleeper.
4.3 Displacement sensor
The instrument for measuring the vertical displacement of the rail relative to the sleeper has an indication error within 0.01 mm.
Contents
Foreword i
1 Scope
2 Symbol
3 Principle
4 Test equipment
5 Test piece
6 Benchmark method test procedure
7 Alternative method test procedure
8 Test report
