Modélisation des structures sensibles aux effets du second ordre

Abstract : This report is part of the objective to adapt the Eurocodes to the scaffolding and shoring structures, aim of the collaboration between the SFECE and the University of Lorraine. A short presentation of the SFECE is carried out in the first part of this report. Both an appropriate model and assumptions that reflect the behavior of the structure are necessary to design a structure. The stresses can be determined by analyzing the first or the second order according to the effects of the deformation of the structure. Indeed when the effects of the deformation increase the effects of loads, it is necessary to take them into account and so to carry out a second order analysis. The Eurocode 3 defines the critical coefficient cr which enables to determine the analysis method: first or second order. We can see that for low rigidity structures such as the scaffolding and shoring structures the critical coefficient cr is often lower than 3. So the imperfections generate significant second order effects which must be taken into account. The main issue is to define the imperfections and the method to take them into account in the analysis. We can differentiate two different approaches: -conventional methods based on the definition of both a global imperfection and a local imperfection -alternative methods based on a single imperfection of same shape that the deformed critical of the structure. Thus in the second part of this report the different methods to define the imperfections will be presented. Then, in the next part, we will compare these methods thanks to the study of a frame structure. This will allow to know the advantages and the drawbacks of each methods and thus to know the method that best reflects the behavior of the structure. After the study of the way to take into account the imperfections, we will determine the way to analyze structures. We will compare the different structural damage requirements suggested by the Eurocode 3. We will also search a method that enables to substitute for the establishment of an initial imperfection, both a safe and reasonable assessment of the structural damage. We will study a vertically loaded structure in the fourth part and a vertically and horizontally loaded structure in the fifth part. Thus, we will define different structural damage requirements that reflect the real damage of a structure with a safety margin.
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Master thesis
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https://hal.univ-lorraine.fr/hal-02346423
Contributor : Charlotte Mercier <>
Submitted on : Tuesday, November 5, 2019 - 9:08:01 AM
Last modification on : Wednesday, November 6, 2019 - 1:47:12 AM

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  • HAL Id : hal-02346423, version 1

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C. Mercier. Modélisation des structures sensibles aux effets du second ordre. Structures. 2016. ⟨hal-02346423⟩

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