Section Structural Analysis

5.1 General

5.2 Geometric imperfections

SECTION 5. STRUCTURAL ANALYSIS C5.1 General

Structural analysis is the process of determination of the effects of actions (forces, impressed strain) in terms of tensional states or strain on a geometrically and mechanically defined structure.

The analysis implies a preliminary idealisation of the structure, based on more or less refined assumptions of behaviour. There are four types of idealisations:

- linear elastic behaviour that assumes, for analysis, uncracked cross sections and perfect elasticity. The design procedures for linear analysis are given in [5.4-EC2];

- linear elastic behaviour with limited redistribution [5.5-EC2]. It is a design (not analysis) procedure based on mixed assumptions, derived from both the linear and non-linear analysis.

- plastic behaviour. Its kinematic approach [5.6-EC2], assumes at ultimate limit state the transformation of the structure in a mechanism through the formation of plastic hinges; in its static approach, the structure is represented by compressed and tensioned elements (strut and tie model);

- non linear behaviour, that takes into account, for increasing actions, cracking, plastification of reinforcement steel beyond yielding, and plasticization of compressed concrete. The design procedures for non-linear analysis are given in [5.7-EC2];

The rules in the EN are technically rather similar to those in the ENV. However, the discontinuities mentioned above have been removed, and the rules have been coordinated between EC2, EC3 and EC4, see 5.2.5. The EN rules are not repeated here.

C5.2. Geometric imperfection 5.2.1 Symbols

Parameter

Symbol

C omment

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