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Performance characteristics EN 10080:2005 - Mechanical properties

EN 10080:2005 Performance characteristics - Mechanical properties 

General

According standard EN 10080:2005 the characteristic value is (unless otherwise indicated) the lower or upper limit of the statistical tolerance interval at which there is a 90 % probability (1 - α = 0,90) that 95 % (p = 0,95) or 90 % (p = 0,90) of the values are at or above this lower limit, or are at or below this upper limit respectively (see Tables below). This definition refers to the long term quality level of production.

Conditions of testing

The conditions of testing should be as specified in this kind of Table:

Manufacturing and delivery conditions of the product	Conditions of testing (test pieces)
Produced in straight lengths by hot rolling	As delivered a or aged b
Produced in straight lengths by cold working	Aged b
Produced as coil and delivered de-coiled	Aged b
Produced and delivered as coil	Straightened and aged b
Welded fabric	Aged a, b, c
Lattice girders	Aged a, b, c
a Aged in the case of dispute. b Aged means: Heating of the test piece to 100 °C, maintaining at this temperature ± 10 °C for a period of 1 h 0 15 + min and then cooling in still air to room temperature. The method of heating is left to the discretion of the manufacturer. c Or as delivered when the constituents are produced in straight lengths by hot rolling.

Tensile properties 

The specified values for the tensile properties (Re , Rm / Re , Agt , and where relevant Re,act. / Re,nom.) shall be the corresponding specified characteristic value with p = 0,95 for Re , and p = 0,90 for Agt , Rm/Re , and Re,act./Re,nom. 

The values Re and Rm shall be calculated using the nominal cross-sectional area of the product. 

For yield strength (Re) the upper yield strength (ReH) shall apply. If a yield phenomenon is not present, the 0,2 % proof strength (Rp0,2) shall be determined.

Shear force of welded or clamped joints

Welded fabric 

The specified value of the shear force of welded joints in welded fabric, Fs , shall be a minimum value. The specified minimum value of Fs shall not be less than 0,25×R e×An , where Re is the specified characteristic yield strength, and An is the nominal cross-sectional area of either: 

a) the larger wire at the joint in a single wire welded fabric, 

b) one of the twin wires in a twin wire welded fabric (twin wires in one direction).

Lattice girders

Welded joints

The specified value for the shear force of a weld point in a lattice girder, Fw , shall be a minimum value. The specified minimum value of Fw shall not be less than

F w ≥ 0,25 × R e,Ch × A Ch or F w ≥ 0,6 × R e,Di × A Di

whichever is the lower.

For the evaluation of the test result for the shear force it is necessary to record how many weld points have been loaded and failed in the same moment.

Clamped joints

Clamped joints are only used for joining the lower chord and the diagonals. The specified value for the shear force of a clamped joint in lattice girders, F d , shall be a minimum value. The specified minimum value of F d shall not be less than

Fd ≥ 0,25 × Re,Di × ADi

Fatigue strength

If submitted to axial force controlled fatigue testing in the fluctuating tension range, the product shall withstand the specified number(s) of stress cycles. The stress shall vary sinusoidally, over the specified range of stress 2σa , from the specified σmax.

Suitability for bending

Suitability for bending shall be determined by the bend and/or rebend test.

The bend test, if required, shall be performed according to EN ISO 15630-1, with a minimum angle of bend of 180°.

After testing the products shall show neither rupture nor cracks visible to a person of normal or corrected vision. The mandrel diameter specified for the bend test shall not exceed the relevant maximum diameter specified in Table below.

Table — Mandrel diameter for the bend test

Nominal diameter d mm	Mandrel diameter max.
≤ 16	3 d
> 16	6 d

The re-bend test, if required, shall be performed according to EN ISO 15630-1.

Test pieces shall be bent through a minimum angle of 90° around a mandrel having a diameter not exceeding the relevant maximum diameter specified in Table below, aged and then bent back by at least 20°.

After the test the specimen shall show no sign of fracture or cracks visible to a person of normal or corrected vision.

Table — Mandrel diameter for the re-bend test

Nominal diameter d mm	Mandrel diameter max.
≤ 16	5 d
> 16 ≤ 25	8 d
> 25	10 d

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