Full scale testing

(1) Full scale testing may be carried out under actual operating conditions, or in a testing facility with the test load components applied by hydraulic or other methods of control.

(2) The conditions for manufacturing the structure should be as for component testing in C.3.1.

(3) The loads applied should not exceed the nominal loads.

(4) Where the service loads vary in a random manner between limits they should be represented by an equivalent series of loads agreed between the supplier and the purchaser.

(5) Alternatively, the test load(s) should equal the unfactored load(s).

(6) The application of loads to the sample should reproduce exactly the application conditions expected for the structure or component in service.

(7) Testing should continue until fracture occurs or until the sample is incapable of resisting the full test load because of damage sustained.

(8) The number of applications of test load(s) to failure should be accurately counted and recorded with observations of the progressive development of cracks.

C.3.3 Acceptance

(1) The criterion for acceptance depends upon whether the structure is required to give a safe life performance or damage tolerance performance . See a and b below:

a) For acceptance of a safe life design the life to failure determined by test, adjusted to take account of the number of test results available, should not be less than the design life as defined in 2.2 as follows:

where

Tl is the design life (in cycles) Tm is the mean life to failure (in cycles)

F is a factor dependent upon the effective number of test results available, as defined in table C.l.

Table C.l: Fatigue test factor F

Results of tests

Number of samples tested

1

2

4

6

8

9

10

100

Identical samples all tested to failure. All samples failed, factors on log mean assuming population standard deviation as log 0,176

3,80

3,12

2,73

2,55

2,48

2,44

2,40

2,09

Identical samples all tested simultaneously. First sample to fail with population standard deviation assumed as log 0,176

3,80

2,67

2,01

1,75

1,60

1,54

1,54

0,91

b) Acceptance of a damage tolerance design is dependent upon the life of a crack reaching a size which could be detected by a method of inspection which can be applied in service. It also depends on the rate of growth of the crack, critical crack length considerations, and the implications for the residual safety of the structure and the costs of repair.

(2) Criteria for factoring the measured life and for acceptance will vary from one application to another and should be agreed with the engineer responsible for acceptance.

C.4 Crack growth data

Guidance on derivation of crack growth data is given in Annex B.

C.5 Reporting

(1) At the conclusion of any testing performed in accordance with this section a type test certificate should be compiled containing the following information:

a) name and address of the test house;

b) accreditation reference of the test facility (where appropriate);

d) name(s) of witnesses;

e) description of sample tested, by means of:

1) reference to serial number where appropriate; or

2) reference to drawing numbers) where appropriate; or

3) description with sketches or diagrams; or

4) photographs;

f) description of load systems applied including references to other European Standards where appropriate;

g) record of load applications and measured reactions to loading, i.e. deflection, strain, life;

h) summary of loads and deformations and stress at critical acceptance points;

i) record of endurance and mode of failure;

j) record of locations of observations by reference to (e 2-4) above;

k) notes of any observed behaviour relevant to the safety or serviceability of the object under test, e.g. nature and location of cracking in fatigue test;

1) record of environmental conditions at time of testing where relevant;

m) statement of validation authority for all measuring equipment used;

n) definition of purpose or objectives of test;

o) statement of compliance or non-compliance with relevant acceptance criteria as appropriate; p) record of names and status of persons responsible for testing and issuing of report; q) report serial number and date of issue.

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