scholarly journals Small Caliber Bulletproof Test of Warships’ Hulls

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3848
Author(s):  
Radosław Kiciński ◽  
Andrzej Kubit
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Method Simulation ◽  
Material Model ◽  
Experimental Results ◽  
Material Constants ◽  
Steel Core ◽  
Calculation Results ◽  
Simulation Results

The article presents the characteristics of 1.3964 steel and the results of firing a 7.62 mm projectile with a steel core. A simplified Johnson–Cook material model for steel and projectile was used. Then, a FEM (finite element method) simulation was prepared to calibrate the material constants and boundary conditions necessary to be used in simulations of the entire hull model. It was checked how projectile modeling affects the FEM calculation results. After obtaining the simulation results consistent with the experimental results, using the model of a modern minehunter, the resistance of the ship’s hull to penetration by a small-caliber projectile was tested.

scholarly journals EFFECT OF FLAT AND HEMISPHERICALLY ENDED CYLINDER BIRD MODEL WITH FINITE ELEMENT MODELLING OF BIRD STRIKE

2019 ◽  
Vol 17 (1) ◽  
pp. 41
Author(s):  
Endah Yuniarti
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Modelling ◽  
Model Simulation ◽  
Material Model ◽  
Stagnation Pressure ◽  
Bird Strike ◽  
Element Modelling ◽  
Element Simulation ◽  
Simulation Results

This research studies influence of bird model on impact pressures during bird strike, namely Hugoniot and Stagnation pressure through initial modelling by numerical simulations using finite element method. Finite element simulation of bird strike have primarily modelled the bird as either a flat or hemispherically ended cylinder. The geometry is simulated with different L/D ratio, 1.4, 1.6, 1.8 and 2.0. Elastic-plastic hydrodynamic material model is used in simulation. Bird model simulation are using lagrangian method and initial velocities are 100, 200 and 300 m/s. Simulation results of hemispherically ended cylinder bird models show variation of L/D ratio provide Hugoniot pressure 10-19 times higher than stagnation pressure in L/D = 1.4, 8-18 times in L/D = 1.6, 9-17 times in L/D = 1.8 and 4-16 times in L/D = 2. The Hugoniot pressure shows a lower value at an L/D ratio of 1.6 compared to other ratios and the Stagnation pressure is higher at L/D ratio 2. As for cylindrical bird model show variation of L/D ratio provide Hugoniot pressure 35-38 times higher than stagnation pressure in L/D = 1.4, 30-47 times in L/D = 1.6, 31-52 times in L/D = 1.8 and 28-48 times in L/D = 2. The Hugoniot pressure shows a lower value at an L/D ratio of 1.4 and 1.6 compared to other ratios and the Stagnation pressure is higher at L/D ratio 2.

Ultraprecision Glass Molding Press for Microgrooves with Different Pitch Sizes

2013 ◽  
Vol 7 (6) ◽  
pp. 678-685 ◽  
Author(s):  
Ryuichi Kobayashi ◽  
◽  
Tianfeng Zhou ◽  
Keita Shimada ◽  
Masayoshi Mizutani ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Glass Surface ◽  
Fem Simulation ◽  
Experimental Results ◽  
Experimental Conditions ◽  
Glass Molding ◽  
Periodic Microstructures ◽  
Simulation Results ◽  
Efficient Manufacturing

Glass molding press is an efficient manufacturing technology to fabricate microstructures on glass. To optimize the experimental conditions for precision replication of periodic microstructures with different pitch sizes, Finite Element Method (FEM) simulation and experiments were carried out to study the glass molding press process. First, the effects of the change in pitch size on stress and geometrical replicating accuracy were evaluated. Thereafter, glass molding experiments were carried out to form microstructures on the glass surface, and the molded microstructures were measured. By comparing the simulation results with experimental results, the FEM simulation was experimentally verified, and the optimal machining conditions were obtained and discussed.

Dynamic Analysis of an Unsymmetrical Rotor Supported by Oil Film Bearing

2003 ◽  
Author(s):  
Zhansheng Liu ◽  
Senlin Huang ◽  
Jiexian Su ◽  
Songbo Xia
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Dynamic Analysis ◽  
Dynamic Characteristic ◽  
Experimental Results ◽  
Oil Film ◽  
Oil Whirl ◽  
Element Method

Unsymmetrical rotor is a type of rotor widely used in engineering, which has different characteristic from symmetrical rotor and is less stable especially. With application to finite element method and Newmark-β method, dynamic characteristic of symmetrical rotor and three types of unsymmetrical rotor are investigated. The numerical and experimental results show that, in the same boundary conditions, speeds of oil whirl and whip are decreasing with the increase of stiffness asymmetry, and become less stable.

Integrated Flow Analysis During Filling and Post-Filling Stage of Semiconductor Encapsulation

1999 ◽  
Vol 122 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Sejin Han ◽  
K. K. Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Flow Analysis ◽  
Rectangular Cavity ◽  
Experimental Results ◽  
Molding Compound ◽  
Filling Stage ◽  
Semiconductor Chip ◽  
Simulation Results ◽  
Good Agreement

In this paper, flow during the filling and post-filling stages in semiconductor chip encapsulation has been analyzed. A finite-element method based on the Hele-Shaw approximation is used for the flow analysis in the chip cavity. The compressibility of the epoxy-molding compound has been considered to analyze the post-filling stage. The model has been verified by comparing resulting predictions with experimental results. Specifically, pressure has been measured in a rectangular cavity and compared with simulation results. The calculated and experimental results show good agreement. [S1043-7398(00)00101-8]

Performance Evaluation and Prediction of Escalator Structure Using FEM-Based Analysis

2013 ◽  
Vol 819 ◽  
pp. 59-64 ◽  
Author(s):  
Jian Cai Zhao ◽  
Xi Chen ◽  
Ze Yu Zhao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Performance Evaluation ◽  
Numerical Calculation ◽  
Experimental Results ◽  
Calculation Results ◽  
Study Performance ◽  
Element Method

The paper applied Finite Element Method (FEM) to study performance of escalator structure. A case study is given to demonstrate the method of the FEM. To validate the results of FEM, some experiments were conducted. The results show that all the test samples meet the requirements of the truss, and the experimental results verify the numerical calculation results.

Application of the Finite Element Method in Screening of Body Turn up Heights for Radial Truck Tires

2001 ◽  
Vol 29 (3) ◽  
pp. 186-196 ◽  
Author(s):  
X. Yan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Material Model ◽  
The Finite Element Method ◽  
Truck Tires ◽  
Contact Constraint ◽  
Nonlinear Mechanical ◽  
Critical Regions ◽  
Constraint Method ◽  
Element Method

Abstract A method is described to predict relative body turn up endurance of radial truck tires using the finite element method. The elastomers in the tire were simulated by incompressible elements for which the nonlinear mechanical properties were described by the Mooney-Rivlin model. The belt, carcass, and bead were modeled by an equivalent orthotropic material model. The contact constraint of a radial tire structure with a flat foundation and rigid rim was treated using the variable constraint method. Three groups of tires with different body turn up heights under inflation and static footprint loading were analyzed by using the finite element method. Based on the detail analysis for stress analysis parameters in the critical regions in the tires, the relative body turn up edge endurance was predicted.

Tire Cornering Simulation Using an Explicit Finite Element Analysis Code

1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Test System ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
Element Method

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.

Upon Impact Numerical Modeling of Foam Materials

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Boundary Conditions ◽  
General Character ◽  
Foam Material ◽  
Various Boundary Conditions ◽  
Specific Behaviour

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.

scholarly journals Shape Sensing of a Complex Aeronautical Structure with Inverse Finite Element Method

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1388
Author(s):  
Daniele Oboe ◽  
Luca Colombo ◽  
Claudio Sbarufatti ◽  
Marco Giglio
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Strain Field ◽  
Element Analysis ◽  
Inverse Finite Element Method ◽  
Shape Sensing ◽  
Definition Of ◽  
High Level ◽  
Element Method

The inverse Finite Element Method (iFEM) is receiving more attention for shape sensing due to its independence from the material properties and the external load. However, a proper definition of the model geometry with its boundary conditions is required, together with the acquisition of the structure’s strain field with optimized sensor networks. The iFEM model definition is not trivial in the case of complex structures, in particular, if sensors are not applied on the whole structure allowing just a partial definition of the input strain field. To overcome this issue, this research proposes a simplified iFEM model in which the geometrical complexity is reduced and boundary conditions are tuned with the superimposition of the effects to behave as the real structure. The procedure is assessed for a complex aeronautical structure, where the reference displacement field is first computed in a numerical framework with input strains coming from a direct finite element analysis, confirming the effectiveness of the iFEM based on a simplified geometry. Finally, the model is fed with experimentally acquired strain measurements and the performance of the method is assessed in presence of a high level of uncertainty.

scholarly journals Finite Element Method modeling of Additive Manufactured Compressor Wheel

2021 ◽  
Author(s):  
Márton Tamás Birosz ◽  
Mátyás Andó ◽  
Sudhanraj Jeganmohan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Method Simulation ◽  
Element Model ◽  
Tensile Tests ◽  
Raw Material ◽  
Isotropic Hardening ◽  
Compressor Wheel ◽  
Material Extrusion ◽  
Element Method

AbstractDesigning components is a complex task, which depends on the component function, the raw material, and the production technology. In the case of rotating parts with higher RPM, the creep and orientation are essential material properties. The PLA components made with the material extrusion process are more resistant than VeroWhite (material jetting) and behave similarly to weakly cross-linked elastomers. Also, based on the tensile tests, Young’s modulus shows minimal anisotropy. Multilinear isotropic hardening and modified time hardening models are used to create the finite element model. Based on the measurements, the finite element method simulation was identified. The deformation in the compressor wheel during rotation became definable. It was concluded that the strain of the compressor wheel manufactured with material extrusion technology is not significant.

Sign in / Sign up

Export Citation Format

Share Document