OS-C501

Offshore Standard DNV-OS-C501, November 2013
Sec.6 Failure mechanisms and design criteria – Page 97
SECTION 6 FAILURE MECHANISMS AND DESIGN CRITERIA
1 Mechanisms of failure
1.1 General
1.1.1 A mechanism of failure is the underlying phenomenon at the material level that determines the mode of
failure. Depending on its level of severity a mechanism of failure can lead to various failure modes. For
example, matrix cracking can lead to seepage of a fluid through the laminate or lead to fracture depending on
the severity of the cracks. Failure mechanism can be regarded as the cause of failure and failure mode as the
effect. The failure terminology used in this standard is shown in Figure 6-1.
Guidance note:
Local and global failure shall be distinguished. On a material level, failure tends to be local, i.e. over an area of a few
cm 2 , or even less. This local failure may have global consequences immediately, or after some growth with time. In
some cases, the local failure does not grow and does not have any global consequences and does not effect any of the
design requirements of the structure. In such a case local failure may be acceptable.
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1.1.2 Only failure mechanisms that are related to critical failure modes, as identified in Sec.3 should be
considered.
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