Serguei Potapov

A robust SPH formulation for solids

The smoothed particle hydrodynamics method such as other meshless methods is a very efficient numerical method for some types of modelling such as fracturing of solids. This technique, initially developed for fluid or gas, was extended to solids but it suffers from severe instability problems. The origins of these instabilities have been identified by the SPH community and solutions were developed to remove them. An overview of the different proposed techniques is presented. Among them it appears that for solids the use of the total Lagrangian formulation is the most simple and valuable solution. In the same time stress points can be added to this new formulation in order to improve accuracy and convergence rate despite an increase in computational cost.

Simulation of the depressurisation occuring at the beginning of a LOCA in a 4-loop PWR

The safety analysis of Pressurised Water Reactors (PWR) is based on the assessment of the consequences of a hypothetical Loss of Coolant Accident (LOCA). The accident supposes that a break occurs on a pipe of the primary circuit. A depressurisation wave propagates from the break through the entire primary circuit, then the circuit empties progressively in diphasic regime. This study focuses on the phase of depressurisation happening during the first milliseconds following the break opening. The geometry of the primary circuit is simplified and represented with a pipe-model to be able to simulate the accident in the entire circuit. The reactor is supposed to work in operating conditions when the accident takes place. After a brief presentation of the geometry and the numerical model, the hydraulic consequences of the LOCA are analysed.

Modeling of the depressurisation induced by a pipe rupture in the primary circuit of a nuclear plant

The safety analysis of Pressurised Water Reactors is based on the assessment of the consequences of a hypothetical Loss Of Coolant Accident. The accident supposes that a break occurs on a pipe of the primary circuit. A depressurisation wave propagates from the break through the entire primary circuit, then the circuit empties progressively in diphasic regime. The geometry of the primary circuit is simplified and represented with a pipe-model to be able to simulate the accident in the entire circuit. After a presentation of the geometry and the numerical model, the hydraulic consequences of the LOCA are analysed.

Mixed DEM/FEM Modeling of Advanced Damage in Reinforced Concrete Structures

AbstractThis paper aims to present a mixed, or combined, numerical approach to modeling advanced degradation and predicting failure in reinforced concrete (RC) structures. The discrete-element meth...