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design values

P(1) The design value Xd of a material property is generally defined as

Ym where

Ym is the partial safety factor for the material property, given in 2.3.3.2 and 2.3.4. In 4.3.5, other definitions apply.

P(2) Design values for the material properties, geometrical data and effects of actions, when relevant, shall be used to determine the design resistance Rd from:

(3) The design value Rd may be determined from tests. Guidance is given in

2.2.4 Geometrical data

P(1) Design values of geometrical data describing the structure are generally represented by their nominal values:

P(2) In some cases the geometrical design values are defined by:

The values of %a are given in the appropriate clauses.

(3) For imperfections to be adopted in the global analysis of the structure, see sections 2.5.1.3 and 4.3.5.4. 2.2.5 Load arrangements and load cases7)

P(1) A load arrangement identifies the position, magnitude and direction of a free action.

P(2) A load case identifies compatible load arrangements, sets of deformations and imperfections considered for a particular verification.

2.3 Design requirements

2.3.1 General

P(1) It shall be verified that no relevant limit state is exceeded. P(2) All relevant design situations and load cases shall be considered

P(3) Possible deviations from the assumed directions or positions of actions shall be considered. P(4) Calculations shall be performed using appropriate design models (supplemented, if necessary, by tests) involving all relevant variables. The models shall be sufficiently precise to predict the structural behaviour, commensurate with the standard of workmanship likely to be achieved, and with the reliability of the information on which the design is based.

2.3.2 Ultimate limit states

2.3.2.1 Verification conditions

P(1) When considering a limit state of static equilibrium or of gross displacements or deformations of the structure, it shall be verified that,

where Ed,dst and Ed,stb are the design effects of destabilizing and stabilizing actions, respectively.

P(2) When considering a limit state of rupture or excessive deformation of a section, member or connection (fatigue excluded) it shall be verified that:

where Sd is the design value of an internal force or moment (or of a respective vector of several internal forces or moments) and Rd is the corresponding design resistance, associating all structural properties with the respective design values (see 2.5.3).

P(3) When considering a limit state of transformation of the structure into a mechanism, it shall be verified that a mechanism does not occur unless actions exceed their design values — associating all structural properties with the respective design values.

P(4) When considering a limit state of stability induced by second-order effects it shall be verified that instability does not occur unless actions exceed their design values — associating all structural properties with the respective design values. In addition, sections shall be verified according to P(2) above. P(5) When considering a limit state of rupture induced by fatigue it shall be verified that

where Dd is the design value of the damage indicator: see Part E.

2.3.2.2 Combinations of actions

P(1) For each load case, design values Ed for the effects of actions shall be determined from combination rules involving design values of actions as identified by Table 2.1.

7 Detailed rules on load arrangements and load cases are given in will be found in the Eurocode 1, Bases of Design and Actions on Structures.

Table 2.1 — Design values for actions for use in the combination of actions

Design situation

Permanent actions Gd

Variable Actions

Accidental actions

Ad

One with its Others with their characteristic value combination value

Persistent and Transient

Accidentala

YGGk YGAGk

YqQk ?oYqQk ?1Qk ?2Qk

YAAk (if Ad is not specified directly)

a If not specified differently elsewhere.

P(2) The design values of Table 2.1 shall be combined using the following expressions (given in symbolic form)8)

— Persistent and transient design situations for verifications other than those relating to fatigue or prestressing (fundamental combinations):

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