OS-C501

Offshore Standard DNV-OS-C501, November 2013
Sec.13 Definitions, abbreviations & figures – Page 177
Table 13-1 Terms (Continued)
Failure mechanism 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 failures. Failure mechanisms are specific to material type.
Failure mode
state of inability to perform a normal function, or an event causing an undesirable or
adverse condition, e.g. violation of functional requirement, loss of component or system
function, or deterioration of functional capability to such an extent that the safety of the
unit, personnel or environment is significantly reduced.
Failure probability probability of failure during a specified time interval such as the design life of a structure.
Failure type
failure types are based on safety margin, intrinsic to a given failure mechanism. A
distinction is made between catastrophic and progressive failures, and between failures
with or without reserve capacity during failure.
Failure
a state of inability to perform a normal function, or an event causing an undesirable or
averse condition, e.g. violation of functional requirement, loss of component or system
function, or deterioration of functional capability to such an extent that the safety of the
unit, personnel or environment is significantly reduced.
Fatigue
in materials or structures, the cumulative and irreversible damage incurred by cyclic or
static application of mechanical and or thermal loads in given environments.
Fibre Reinforced Plastic a general term polymeric composite reinforced by fibres.
(FRP)
Fibre
single filament, rolled or formed in one direction, and used as the principal constituent of
woven or non-woven composite materials.
Filament
the smallest unit of a fibrous material. The basic units formed during drawing and spinning,
which are gathered into strands of fibre. It is a continuous discrete fibre with an effective
diameter in the range of few micrometers depending on the source.
Functional requirement a functional requirement is defined as a requirement that the global structure has to fulfil.
Glass Fibre Reinforced general term polymeric composite reinforced by glass fibres.
Plastic (GRP)
Homogeneous
descriptive term for a material of uniform composition throughout. A medium that has no
internal physical boundaries.
Inspection
activities, such as, measuring, examination, testing, gauging one or more characteristic of
a product or a service, and comparing the results with specified requirements to determine
conformity.
Installation
operation related to setting up a system, components or parts.
Interface
boundary or transition zone between constituent materials, such as the fibre/matrix
interface, or the boundary between plies of a laminate or layers of a sandwich structure.
Boundary between different materials in a joint. An interface can also be the area where
two components or parts touch each other.
Lamina (Laminae) same as ply (plural of lamina).
Laminate
layers of a plies bonded together to form a single structure. Also the process to build a
laminate.
Laminate ply
one layer of a laminated product.
Layer
a single ply of lay up or laminate.
Limit State
state beyond which the structure fails to meet a particular functional requirement. A
functional requirement can be related to various limit states depending on the modes of
failure mode. Two limit state categories are considered in the standard.
Load effect
effect of a single load or combination of loads on the system, such as stress, strain,
deformation, displacement, acceleration, etc.
Load factor
partial safety factor by which the characteristic load is multiplied to obtain the design load.
Load effect factor partial safety factor by which the characteristic load effect is multiplied to obtain the design
load effect.
Load
assembly of concentrated or distributed forces acting on a structure (direct loads), or cause
of imposed or constrained deformations in a structure (indirect loads).
Local buckling
unstable displacement of a sub-structural part, such as a lamina, face or cell caused by
excessive compression and or shear.
Manufacturer
the party, which manufactures or supplies equipment to perform the duties specified by the
Contractor
Matrix
the cured resin or polymer material in which the fibre system is imbedded in a ply or
laminate.
Monolithic structure laminate consisting uniquely of composites materials except core materials; also called
single-skin structure.
Off-axis
not coincident with the symmetry axis; also called off-angle.
On-axis
coincident with the symmetry axis; also called on-angle.
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