OS-C501

Offshore Standard DNV-OS-C501, November 2013
Sec.4 Materials - laminates – Page 65
7.5.2 If the temperature has locally exceeded the Tg of the component it is very likely that permanent damage
has been made to the component in that area.
7.5.3 If the temperature remained locally under Tg damage may be introduced due to overloads from other
parts of the structure.
8 Qualification of material properties
8.1 Introduction
8.1.1 All material properties needed to describe the performance of a component shall be documented.
8.1.2 As a general principal, material properties should be obtained form test results of laminates that represent
the laminates of the component as closely as possible.
Guidance note:
If laminates are used on pipes, it is recommended to obtain material data from tubular specimens.
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8.1.3 Material properties may be documented by the following methods:
— direct measurements
— qualification against representative data
— qualification against manufacturers data
— qualification against data from the open literature
— qualification by component testing.
8.1.4 Each individual material property may be qualified by any of the different methods.
8.1.5 Which data can be used for qualification depends mainly on two aspects:
— data obtained from laminates that are similar to the laminates used in the component
— data obtained from reputable sources.
8.2 General test requirements
8.2.1 All relevant information about the material tested, the test method, and the test conditions shall
accompany test results. The information requested in [1.2] shall be provided.
8.2.2 Static test results shall be reported as mean, standard deviation, coefficient of variation, and number of
test specimens. The characteristic values of static tests shall be calculated as described in [2.4].
8.2.3 Long-term test results shall be reported as mean regression curve, standard deviation with respect to time
or cycles, number of test specimen, range of test time or number of cycles. Test points shall be spread out
relatively evenly over the logarithmic test period. The characteristic values of long-term tests shall be
calculated as described in [3.11].
8.3 Selection of material qualification method
8.3.1 The test results shall apply to the laminates used in the component to be designed and built. Test results
are only applicable if the test laminate and the component laminate are similar enough that the test results are
valid or conservative for the actual component.
8.3.2 If the material is the same as an already tested material no further testing is required. The same material
means:
— same fibres, same weave or fabric from the same producer
— same matrix system (same resin, curing agent and fillers)
— similar production process, as defined in [6.2.2].
8.3.3 If the material is similar to an already tested material qualification against a representative material may
be carried out. Requirements for similarity are given in [8.6], requirements for representative data are given in
[8.5].
8.3.4 Direct measurements as described in [8.4] shall be carried out if [8.3.2] or [8.3.3] cannot be applied.
8.4 Direct measurement
8.4.1 The various properties of a composite may be measured directly for a particular material. Data will be
valid for that particular material that was tested. The material shall be characterised as required in [1.2].
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