aluminium in commercial vehicles - European Aluminium Association

62 EUROPEAN ALUMINIUM ASSOCIATION ALUMINIUM IN COMMERCIAL VEHICLES CHAPTER VI
5. Limit state design
5.1. Philosophy
Limit state design and partial
safety factor method are the
methods that the new design
standards are based on. In
Europe the EN 19xx standards
are the basis for this method for
EN 1990 Eurocode – Basis for structural design
EN 1991 Eurocode 1 – Actions on structures. All parts
EN 1999 Eurocode 9 – Design of aluminium structures
EN 1990 gives the partial safety
factor on loads and rules for
combination of loads to give the
different action effects.
5.2. What is the ultimate
limit state
The ultimate limit state is the
condition where the safety of the
structure is calculated. A structure
shall not collapse and design
in accordance with the ultimate
limit state shall avoid structural
failure.
The partial safety factor for the
resistance (γ ) shall take care of
M
EN 1991 gives the characteristic
loads for structures and buildings
such as self weight, live loads,
wind loads, snow loads, traffic
loads etc.
the scattering of the strength
properties and the geometry of
the cross section. For connections
the partial safety factor
shall in addition take care of
uncertainties in the welds and in
the bolts and bolt configuration.
The partial safety factor for the
load effects (γ ) shall take care of
F
the scattering of the determination
of the loads and the probability
in the combination of dif-
all structural materials in civil
engineering. For aluminium the
actual standards are:
EN 1999 gives the design rules
for aluminium structures.
ferent loads. The partial safety
factor is different for the different
types of loads, their certainty
and how they are combined.
Dead loads (i.e. self weight of
structure) have a low partial safety
factor while the live load (i.e.
all forces that are variable during
operation, e.g. weight of goods,
road vibrations etc…) has a higher
partial safety factor.