Robust and efficient non-linear SSI with Code_Aster and Miss3D
by A. Nieto-Ferro, G. Devesa et N. Greffet, EDF R&D / AMA
The chaining of Code_Aster and MISS3D, which requires the use of the command CALC_MISS), relies on a BEM-FEM coupling approach. It allows to take into account soil-structure interaction (SSI) in dynamic calculations for seismic analysis. However, this approach is based on a frequency domain resolution and therefore, only linear problems can be solved so far.
The new hybrid Laplace-time domain approach (HLTA), which is also available within the command CALC_MISS and which also uses the soil impedance computed with MISS3D in the frequency domain, allows to perform nonlinear transient calculations with DYNA_NON_LINE. This research work, carried out in the framework of a PhD, has been supervised by the Ecole Centrale Paris, EDF R&D and LaMSID.
In addition to the new test case MISS03, the HLTA has been validated on an industrial-type case, based on the SMART benchmark (asymmetric model of reinforced concrete building, ¼ scale, which was tested on the vibrating table AZALEE at CEA Saclay).
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In the thin shell FEM numerical model, nonlinearities are due to both damaging behaviour of concrete and plasticity of steels. A linear stratified soil with realistic properties is considered. Then, the solution obtained with the HLTA is compared to a full-FEM solution where the soil domain is meshed until bedrock (in our case 130 m depth). Two different positions of the FEM-BEM interface have been tested, one on the free-surface and the other, embedded into the ground (this case would correspond to the inclusion of nonlinearities in a bounded area located under the floor).
Assuming the full-FEM solution as the reference, encouraging results on response spectra (SRO) and on damage assessment at the end of the considered seismic loading are obtained.
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REFERENCES
[1] A. Nieto Ferro, D. Clouteau, N. Greffet, G. Devésa, On a Hybrid Laplace-Time Domain Approach to Dynamic Interaction Problems. European Journal of Computational Mechanics, 2012.
DOI:10.1080/17797179.2012.731254