Safety of Nuclear Power Plants against the Aircraft Attack

Abstract

This paper presents the nonlinear dynamic analysis of the reinforced concrete building of nuclear power plant to the aircraft impact. The dynamic load is defined in time on the base of the simulation of the airplane impact considering real stiffness, masses, direction and velocity of the flight. The dynamic response is calculated in the system ANSYS using the transient nonlinear analysis solution method. The damage of the concrete wall is evaluated in accordance with the standard NDRC considering the spalling, scabbing and perforation effects. The simple and detailed calculations of the wall damage are compared.

Numerical and Experimental Analysis of Welds in Steel Structural Element

“…Three variants of FEM mesh density (basic size of element side was 3, 2 and 1 mm, see Figs. [3][4][5] were performed for each of the model. Compare/sensitivity stress-strain analysis based on bilinear and multilinear stress-strain diagrams of basic steel material, heat-affected zone and weld material were done for each numerical model and FEM mesh density.…”

“…Numerical modeling is increasingly promoting into design practice. Using powerful computers and efficient software systems can provide valuable results, which serve to increase the reliability of the proposed support systems and elements [1] as well as to a qualitatively higher level in the design of building structures [2][3][4][5][6][7][8][9]. An important tool for mathematical modeling is particularly the Finite Element Method -FEM, whose principle is to discrete continuum to certain (finite) number of elements and the determination of calculated parameters in individual nodes.…”

Improved Element Erosion Function for Concrete-Like Materials with the SPH Method

“…In the case of the SPH method, the integration points also represent particles (one integration point per particle), while the numerical integration takes place in the form (5). This means that, in the case of both the FEM and the SPH methods, the computational requirements do not necessarily have to increase above all limits as a result of the increasing number of elements or SPH particles.…”

“…On top of that, before the execution of the simulation an assumption often has to be made regarding the type of failure that will be decisive so it is possible to select a material model at all [3]. The response of the concrete also depends on the character of the load [4][5][6][7], which makes the choice even more complicated. Generally, in the case of high-speed loading it is necessary to use a material model which takes strain rate into consideration [8][9][10].…”

Concrete Targets with Heterogeneities under Impact Loading

“…Concrete, as the mixture of a concrete additive (or aggregate for short), a cement binder, and water, does not constitute a regular structure from any perspective or at any scale; with respect to this fact, not even the behaviour of the given structures can be assumed to remain identical in all cases. The introduced randomness is further multiplied by the type of load, which is invariably comprised in structural mechanics analyses [4][5][6].…”