Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

# Application of the Generalized Nonlinear Constitutive Law to Hollow-Core Slabs

Version 1 : Received: 28 July 2021 / Approved: 29 July 2021 / Online: 29 July 2021 (16:11:28 CEST)

How to cite: Staszak, N.; Garbowski, T.; Ksit, B. Application of the Generalized Nonlinear Constitutive Law to Hollow-Core Slabs. Preprints 2021, 2021070672 (doi: 10.20944/preprints202107.0672.v1). Staszak, N.; Garbowski, T.; Ksit, B. Application of the Generalized Nonlinear Constitutive Law to Hollow-Core Slabs. Preprints 2021, 2021070672 (doi: 10.20944/preprints202107.0672.v1).

## Abstract

The non-linear analysis of hollow-core concrete slabs requires the use of advanced numerical techniques, proper constitutive models both for concrete and steel as well as particular computational skills. If prestressing, cracking, crack opening, material softening, etc. are also to be taken into account, then the computational task can far exceed the capabilities of an ordinary engineer. In order for the calculations to be carried out in a traditional design office, simplified calculation methods are needed. Preferably based on the linear finite element (FE) method with a simple approach that takes into account material nonlinearities. In this paper the simplified analysis of hollow-core slabs based on the generalized nonlinear constitutive law is presented. In the proposed method a simple decomposition of the traditional iterative linear finite element analysis and the non-linear algebraic analysis of the plate cross-section is used. Through independent analysis of the plate cross-section in different deformation states, a degraded plate stiffness can be obtained, which allows iterative update of displacements and rotations in the nodes of the FE model. Which in turn allows to update the deformation state and then correct translations and rotations in the nodes again. The results obtained from the full detailed 3D nonlinear FEM model and from the proposed approach are compared for different slab cross-sections. The obtained results from both models are consistent.

## Keywords

generalized nonlinear constitutive law; finite element analysis; nonlinear materials; composite structures

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