scholarly journals Comparison of Numerical Simulation Techniques of Ballistic Ceramics under Projectile Impact Conditions

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 18
Author(s):  
Pawel Zochowski ◽  
Marcin Bajkowski ◽  
Roman Grygoruk ◽  
Mariusz Magier ◽  
Wojciech Burian ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Hybrid Method ◽  
Experimental Tests ◽  
Failure Criteria ◽  
Ceramic Tiles ◽  
Projectile Impact ◽  
Backing Plate ◽  
Composite Armor ◽  
Steel Composite

This article presents an analysis of the effectiveness of available numerical techniques in mapping the characteristic behavior of ballistic ceramics under projectile impact conditions. As part of the work, the ballistic tests were performed on the layered ceramic/steel composite armor and tested with the 7.62 × 39 mm, armor-piercing incendiary (API) BZ projectile. The experimental tests were then mapped using computer simulations. In numerical analyses, four different techniques were used to describe cubic ceramic tiles Al2O3 placed on the ARMOX 500T steel backing plate, i.e.,: the Finite Element Method without Erosion (FEM), Finite Element with erosion (FEM + Erosion), Smoothed Particles Hydrodynamics (SPH) and a hybrid method that converts finite elements to SPH particles after exceeding the defined failure criteria (FEM to SPH conversion). The effectiveness of the individual methods was compared in terms of quality (mapping of characteristic phenomena occurring during the penetration process), quantity (bulge height of the backing plate) and time needed to complete the calculations. On the basis of the results of the experiments and numerical simulations, it was noticed that the most accurate reproduction of the phenomenon of ballistic impact of AP projectiles on ceramic/steel composite armor can be obtained by using a hybrid method, incorporating the conversion of finite elements into SPH particles. This method should be used in cases where accuracy of the results is more important than the time required to complete the calculations. In other situations where the purpose of the calculation is not to determine, for example, the exact value of penetration depth but only to observe a certain trend, the FEM method with defined erosion criteria (variant 2), which is more than 10 times faster, can be successfully used.

scholarly journals Experimental and numerical investigation of the effect of interlayer on the damage formation in a ceramic/composite armor at a low projectile velocity

2016 ◽  
Vol 30 (1) ◽  
pp. 88-106 ◽  
Author(s):  
A Tasdemirci ◽  
G Tunusoglu
Keyword(s):  
Stress Wave ◽  
High Stress ◽  
Test System ◽  
Wave Transmission ◽  
Front Face ◽  
Low Velocity ◽  
Projectile Impact ◽  
Backing Plate ◽  
Composite Armor ◽  
The Impact

The damage formation in a multilayered armor system without and with an interlayer (rubber, Teflon, and aluminum foam) between the front face ceramic layer and the composite backing plate were investigated experimentally and numerically. The projectile impact tests were performed in a low-velocity projectile impact test system and the numerical studies were implemented using the nonlinear finite element code LS-DYNA. The results of numerical simulations showed that the stress wave transmission to the composite backing plate decreased significantly in Teflon and foam interlayer armor configurations. Similar to without interlayer configuration, the rubber interlayer configuration led to the passage of relatively high stress waves to the composite backing plate. This was mainly attributed to the increased rubber interlayer impedance during the impact event. The numerical results of reduced stress wave transmission to the backing plate and the increased damage formation in the ceramic front face layer with the use of Teflon and foam interlayer was further confirmed experimentally.

scholarly journals Calculations of Electrodynamic Forces in Three-Phase Asymmetric Busbar System with the Use of FEM

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5477
Author(s):  
Michał Szulborski ◽  
Sebastian Łapczyński ◽  
Łukasz Kolimas ◽  
Łukasz Kozarek ◽  
Desire Dauphin Rasolomampionona
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Mechanical Strength ◽  
Natural Frequency ◽  
Power Grid ◽  
Experimental Tests ◽  
Three Phase ◽  
Electrodynamic Forces ◽  
Selection Of

Proper busbar selection based on analytical calculations is of great importance in terms of power grid functioning and its safe usage. Experimental tests concerning busbars are very expensive and difficult to be executed. Therefore, the great advantage for setting the valid parameters for busbar systems components are analytical calculations supported by FEM (finite element method) modelling and analysis. Determining electrodynamic forces in busbar systems tends to be crucial with regard to subsidiary, dependent parameters. In this paper analytical calculations of asymmetric three-phase busbar system were carried out. Key parameters, like maximal electrodynamic forces value, mechanical strength value, busbar natural frequency, etc., were calculated. Calculations were conducted with an ANSYS model of a parallel asymmetric busbar system, which confirmed the obtained results. Moreover, showing that a model based on finite elements tends to be very helpful in the selection of unusually-shaped busbars in various electrotechnical applications, like switchgear.

Finite element investigation of fibre-reinforced concrete deck slabs without internal steel reinforcement

1994 ◽  
Vol 21 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Leon D. Wegner ◽  
Aftab A. Mufti
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Plain Concrete ◽  
Experimental Tests ◽  
Failure Criteria ◽  
Steel Reinforcement ◽  
Nonlinear Finite Element ◽  
Fibre Reinforced Concrete ◽  
Deck Slabs ◽  
Failure Loads

Experimental tests on half-scale models have demonstrated that polypropylene-fibre-reinforced concrete (PFRC) bridge deck slabs completely devoid of conventional steel reinforcement will fail by punching shear under concentrated loads considerably greater than those specified for design, provided the top flanges of the supporting girders are adequately restrained from moving laterally. Similar models were analyzed using nonlinear finite element techniques in order to reproduce experimentally observed load–deflection behaviours and failure loads. Commonly available concrete failure criteria for plain concrete was incorporated into the material model used for the PFRC deck slab. Results of the finite element analyses are presented. It is shown that while predicted load–deflection paths were less than satisfactory, accurate predictions of failure loads were achieved, but only after considerable tuning of various modelling parameters. Key words: nonlinear finite element method, bridge decks, fibre-reinforced concrete.

Analysis of Stiffened Plates Using the Boundary Element and Finite Element Hybrid Method

1991 ◽  
Author(s):  
Hui-Ru Shih ◽  
Roger C. Duffield
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Boundary Element ◽  
Hybrid Method ◽  
Plate Boundary ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Compatibility Conditions ◽  
Integral Equation Formulation ◽  
Bending Problems

Abstract The boundary element and finite element hybrid method, based on a combination of unstiffened plate boundary element method and stiffener finite elements, is employed for static analysis of concentrically stiffened plates subjected to transverse loading. The integral equation formulation and its boundary element solution procedures for bending of a unstiffened plate are briefly reviewed. The algorithm which permits coupling of the unstiffened plate boundary elements with the beam (stiffener) finite elements is presented. The numerical implementations of the equilibrium and compatibility conditions along the interface between the plate and its stiffener are given in detail. Numerical examples illustrate the accuracy as well as the capability of the proposed method to determine the solution of stiffened plate bending problems.

scholarly journals A New Mixed Functional-probabilistic Approach for Finite Element Accuracy

2020 ◽  
Vol 20 (4) ◽  
pp. 799-813
Author(s):  
Joël Chaskalovic ◽  
Franck Assous
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Asymptotic Relation ◽  
Probabilistic Approach ◽  
Random Variable ◽  
High Order ◽  
Relative Accuracy ◽  
The Difference ◽  
New Perspective

AbstractThe aim of this paper is to provide a new perspective on finite element accuracy. Starting from a geometrical reading of the Bramble–Hilbert lemma, we recall the two probabilistic laws we got in previous works that estimate the relative accuracy, considered as a random variable, between two finite elements {P_{k}} and {P_{m}} ({k<m}). Then we analyze the asymptotic relation between these two probabilistic laws when the difference {m-k} goes to infinity. New insights which qualify the relative accuracy in the case of high order finite elements are also obtained.

scholarly journals Snow fence load on a house roof with tiles

2018 ◽  
Vol 184 ◽  
pp. 02001
Author(s):  
Cornel Cătălin GavrilĂ ◽  
Mihai -Tiberiu LateŞ
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Final Part ◽  
Ceramic Tiles ◽  
Element Analysis ◽  
Snow Fence ◽  
The Finite Element Analysis ◽  
Virtual Modeling ◽  
General Aspects

Virtual modeling of mechanical structures, using computer performant software, is largely used in many fields. The paper presents some aspects regarding the loads on a snow fence mountig system, placed on a house roof with ceramic tiles. First, there are presented some general aspects of the snow fence types and mounting systems used. Then, there are Then there are presented the aspects about virtual modeling of these parts, using CATIA software. Also, there are presented some aspects about the Finite Element Analysis, respectively the results of this. In the paper final part, there are presented the conclusion.

DISCRETE COMPACTNESS FOR p AND hp 2D EDGE FINITE ELEMENTS

2003 ◽  
Vol 13 (11) ◽  
pp. 1673-1687 ◽  
Author(s):  
DANIELE BOFFI ◽  
LESZEK DEMKOWICZ ◽  
MARTIN COSTABEL
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Model Problem ◽  
Finite Element Approximation ◽  
Stability Estimate ◽  
Element Approximation ◽  
Dimensional Model ◽  
Compactness Property ◽  
One Dimensional ◽  
Discrete Compactness

In this paper we discuss the hp edge finite element approximation of the Maxwell cavity eigenproblem. We address the main arguments for the proof of the discrete compactness property. The proof is based on a conjectured L2 stability estimate for the involved polynomial spaces which has been verified numerically for p≤15 and illustrated with the corresponding one dimensional model problem.

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