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The mechanical response of blast-resistant vehicles, such as Infantry Fighting Vehicles (IFVs), Mechanized Infantry Combat Vehicles (MICVs), Armored Personal Vehicles (APVs), and Mine-Resistant Ambush-Protected (MRAP) vehicles, is crucial for their effective design. When designing armored vehicles, it is important to achieve a balance between rigid designs that transmit blast forces to the troop's cabins and softer designs that prevent excessive structure deformation hazardous to the troops. This study investigates the performance of V-shaped plates at different angles under blast loading. The focus is on modeling blast effects using the Conventional Weapon (ConWep) method and the Johnson-Cook material model. The material used for V-shaped protective plates STRENX700 (S690QL) armor steel is commonly used for blast protection in Anti-Landmine (ALM) Vehicles. The blast-wave induces large deformation, erosion, high strain rates, non-linear material behavior and fragmentation. The numerical simulation results are presented in the form of vertical displacement of the central node on the protective plate, von Mises equivalent stress, and equivalent plastic strain. [ABSTRACT FROM AUTHOR]

This paper presents a comparative analysis of numerical simulations of blood flow through the left ventricle using SPH (LS-DYNA) and FVM (Ansys Fluent) solvers. Numerical simulations based on SPH and FVM methods can provide a more comprehensive understanding of cardiac blood flow patterns. In Fluent, left ventricle walls were modeled as boundary conditions with zero fluid velocity, while in the LS-DYNA software the walls were modeled with fixed particles. Boundary conditions were also prescribed on the appropriate regions (inlet, outlet, symmetry). In both programmes, inlet and outlet velocities were defined using table functions corresponding to the real cardiac cycle. For generating fluid flow in SPH, injection particles at mitral valve and deactivation planes at aortic semilunar valve were used. Numerical analysis results are given comparatively in both cases at the corresponding times. By comparing the results, it can be concluded that SPH can be efficiently used for the analysis of blood flow through the left ventricle. Although the modeling procedure, as well as the calculation itself, takes much longer to execute using SPH, this method offers possibilities such as studying FSI phenomena or tracking the movement of particles through the fluid domain. [ABSTRACT FROM AUTHOR]

The procedure for identifying concrete damage plasticity material model parameters is presented in this paper. Concrete damage plasticity material model represents a constitutive model which is based on a combination of theory of plasticity and theory of damage mechanics. This material model is often used in solving geotechnical problems due to its realistic description of mechanical behavior of concrete material. Theoretical basis of concrete damage plasticity material model and material parameters identification procedure are presented in this paper. Proposed identification procedure is applied on experimental data from uniaxial compression and tension load-unload tests taken from literature. By applying experimental data, stress-strain curve is created. Based on stress-strain load-unload curve, stress-plastic strain and stress-degradation dependences are created which are necessary for material parameters identification. Using these dependences material parameters are determined. Verification of estimated parameters is performed in PAK software package using concrete damage plasticity material model. Finite element model is created for numerical simulations of uniaxial compression and tension tests. Numerical simulation results are compared with experimental data. By comparing numerical simulation results and experimental data it can be concluded that this procedure is effective for determining concrete damage plasticity model parameters. [ABSTRACT FROM AUTHOR]

Efficient memory handling is one of the key issues that engineers and programmers face in developing software for numerical analysis such as the Finite Element Method. This method operates on huge matrices that have a large number of zero coefficients which waste memory, so it is necessary to save it and to work only with non-zero coefficients using so called "SPARSE" matrices. Analysis of two methods used for the improvement of "SPARSE" matrix creation is presented in this paper and their pseudo code is given. Comparison is made on a wide range of problem sizes. Results show that "indexing" method is superior to "dotting" method both in memory usage and in elapsed time. [ABSTRACT FROM AUTHOR]

A stress-strain history in the material of real concrete structures is usually unknown. An effect of concrete degradation is analyzed to describe how the initial degradation parameter can describe the stress-strain history. The idea is to introduce the initial damage of the structure by the degradation parameter to calculate the internal variables of the constitutive model. Six numerical examples are proposed to verify the methodology for various loading conditions. Based on the obtained results, it was shown that unknown stress-strain history could be successfully represented using the original material parameters and the initial degradation of the concrete. The stress-strain behavior of the damaged concrete is successfully simulated and essential for the structural analysis of civil engineering structures. [ABSTRACT FROM AUTHOR]