Real-time calculation of the initial angle of projection for fragments in cylindrical warheads

2021 ◽  
pp. 154851292098267
Author(s):  
David Felix ◽  
Ian Colwill ◽  
Paul Harris
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Initial Angle ◽  
Element Analysis ◽  
Cylindrical Casing ◽  
Time Calculation ◽  
Projection Angle ◽  
Computationally Intensive ◽  
Improved Accuracy ◽  
Speed And Accuracy

This paper presents an improvement in the speed and accuracy of calculating the initial angle of projection of fragments for exploding cylindrical shells. It is a fast tool that can be used by designers, where existing approaches, such as computationally intensive Finite Element Analysis, are preventively slow. An enhanced Taylor equation is presented using available experimental data and the effect of the changing shape of the warhead’s cylindrical casing on the fragment’s initial projection angle. The resulting equation is computationally fast as it uses uncomplicated equations and provides improved accuracy for estimating a fragment’s initial angle of projection in comparison to existing work.

Computer Modeling of a Tire under Cornering Loads

1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves
Keyword(s):  
Finite Element Analysis ◽  
Geometric Approach ◽  
Lateral Force ◽  
Slip Angle ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Slip Effects ◽  
Improved Accuracy ◽  
Nonlinear Geometric ◽  
Good Agreement

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.

Three Approaches for Managing Stiffness in Origami-Inspired Mechanisms

2018 ◽  
Author(s):  
Alden Yellowhorse ◽  
Larry L. Howell
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Engineering Applications ◽  
Element Analysis ◽  
Advantages And Disadvantages ◽  
Large Size ◽  
Selection For

Ensuring that deployable mechanisms are sufficiently rigid is a major challenge due to their large size relative to their mass. This paper examines three basic types of stiffener that can be applied to light, origami-inspired structures to manage their stiffness. These stiffeners are modeled analytically to enable prediction and optimization of their behavior. The results obtained from this analysis are compared to results from a finite-element analysis and experimental data. After verifying these models, the advantages and disadvantages of each stiffener type are considered. This comparison will facilitate stiffener selection for future engineering applications.

Validation of Nitinol SMA Characteristics Using Finite Element Analysis and Closed Form Solutions

2013 ◽  
Vol 856 ◽  
pp. 147-152
Author(s):  
S.H. Adarsh ◽  
U.S. Mallikarjun
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Closed Form ◽  
Closed Form Solution ◽  
Form Solution ◽  
Fe Analysis ◽  
Element Analysis ◽  
Complex Behaviour ◽  
Closed Form Solutions

Shape Memory Alloys (SMA) are promising materials for actuation in space applications, because of the relatively large deformations and forces that they offer. However, their complex behaviour and interaction of several physical domains (electrical, thermal and mechanical), the study of SMA behaviour is a challenging field. Present work aims at correlating the Finite Element (FE) analysis of SMA with closed form solutions and experimental data. Though sufficient literature is available on closed form solution of SMA, not much detail is available on the Finite element Analysis. In the present work an attempt is made for characterization of SMA through solving the governing equations by established closed form solution, and finally correlating FE results with these data. Extensive experiments were conducted on 0.3mm diameter NiTinol SMA wire at various temperatures and stress conditions and these results were compared with FE analysis conducted using MSC.Marc. A comparison of results from finite element analysis with the experimental data exhibits fairly good agreement.

Direct Comparison of Some Recent Rubber Elasticity Models

2000 ◽  
Vol 73 (2) ◽  
pp. 366-384 ◽  
Author(s):  
D. J. Seibert ◽  
N. Schöche
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Element Analysis ◽  
Material Parameters ◽  
Complex Membrane ◽  
The Finite Element Analysis ◽  
Generic Class ◽  
Cubic Model ◽  
Polynomial Models ◽  
Special Case

Abstract The paper compares the Arruda—Boyce model, the van der Waals model and the Reduced Polynomial model—a generic class of polynomial models of which Yeoh's cubic model is a special case—in their ability to predict multiaxial deformation states on the basis of uniaxial measurements. These models are reviewed in the light of novel experimental data, giving ample space to the derivation of the equations needed for optimization of the material parameters. The technological relevance of these findings is exemplified in the finite element analysis (FEA) of a complex membrane.

Incorporation of Spinal Flexibility Measurements Into Finite Element Analysis

1990 ◽  
Vol 112 (4) ◽  
pp. 481-483 ◽  
Author(s):  
Mack G. Gardner-Morse ◽  
Jeffrey P. Laible ◽  
Ian A. F. Stokes
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stiffness Matrix ◽  
Beam Element ◽  
Technical Note ◽  
Element Analysis ◽  
Spinal Motion ◽  
Spinal Flexibility

This technical note demonstrates two methods of incorporating the experimental stiffness of spinal motion segments into a finite element analysis of the spine. The first method is to incorporate the experimental data directly as a stiffness matrix. The second method approximates the experimental data as a beam element.

scholarly journals Residual Stress Distribution in Feal Weld Overlay on Steel

1994 ◽  
Vol 364 ◽  
Author(s):  
X.-L. Wang ◽  
S. Spooner ◽  
C. R. Hubbard ◽  
P. J. Maziasz ◽  
G. M. Goodwin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Post Weld Heat Treatment ◽  
Residual Stress Distribution ◽  
Element Analysis ◽  
Weld Overlay

AbstractNeutron diffraction was used to measure the residual stress distribution in an FeAl weld overlay on steel. It was found that the residual stresses accumulated during welding were essentially removed by the post-weld heat treatment that was applied to the specimen; most residual stresses in the specimen developed during cooling following the post-weld heat treatment. The experimental data were compared with a plasto-elastic finite element analysis. While some disagreement exists in absolute strain values, there is satisfactory agreement in strain spatial distribution between the experimental data and the finite element analysis.

The Finite Element Analysis of Omni-Direction Side-Loading Forklift Truck Lifting System Based on COSMOSWorks

2012 ◽  
Vol 184-185 ◽  
pp. 534-537
Author(s):  
Jing Jing Zhou ◽  
Ai Dong Guo ◽  
Chun Hui Li ◽  
Zhen Jiang Lin ◽  
Tie Zhuang Wu
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Optimization ◽  
Experimental Measurements ◽  
Element Analysis ◽  
Forklift Truck ◽  
The Finite Element Analysis ◽  
Lifting System

By setting contact sets, achieved overall analysis results of the mechanical properties with omni-direction side-loading forklift truck lifting system based on COSMOSWorks. And made an experimental measurements to omni-direction side-loading forklift truck lifting system by electrometric methods. There was a good relevance between experimental data and calculation values, and the deviation was basically within the 10 percent allowed. Finally, in this way it verified the correctness and reliability of the finite element analysis by experimental measurements. Ensured the omni-direction side-loading forklift truck lifting system could be safe and efficient to work. And also it laid a foundation for subsequent structural optimization.

Implosion Analysis of Concrete Cylindrical Vessels

1979 ◽  
Vol 101 (1) ◽  
pp. 98-102
Author(s):  
H. Suzuki ◽  
W. F. Chen ◽  
T. Y. Chang
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Fracture Behavior ◽  
Constitutive Relations ◽  
Analysis Procedure ◽  
Material Behavior ◽  
Ultimate State ◽  
Element Analysis ◽  
Proposed Model ◽  
Effect Of Hydrostatic Pressure

Concrete constitutive relations which can simulate the overall material behavior up to and including its ultimate state under general triaxial loading conditions have been developed. The proposed constitutive relations include: 1) plastic deformation considering the effect of hydrostatic pressure, 2) a dual criterion predicting the fracture of concrete in terms of either stresses or strains, and 3) post-fracture behavior of concrete. Corresponding to the constitutive model, a finite element analysis procedure has also been utilized. Based on the proposed model, implosion pressures and load-deformation responses of several concrete vessels were obtained. The numerical results correlate quite well with the experimental data when the dual criterion was used.

scholarly journals Temperature-Dependence of Rubber Hyperelasticity Based on the Eight-Chain Model

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 932 ◽  
Author(s):  
Xintao Fu ◽  
Zepeng Wang ◽  
Lianxiang Ma ◽  
Zhaoxuan Zou ◽  
Qingling Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Rubber ◽  
Temperature Dependence ◽  
Large Temperature ◽  
Chain Model ◽  
Element Analysis ◽  
Filled Rubber ◽  
Different Temperatures

Rubber-based materials are widely used in a variety of industrial applications. In these applications, rubber components withstand various loading conditions over a range of temperatures. It is of great significance to study the mechanical behavior of vulcanized rubber at different temperatures, especially in a range of high temperatures. The temperature dependence of the constitutive behavior of filled rubber is important for the performance of the rubber. However, only a few constitutive models have been reported that investigate the stress–temperature relationship. In this paper, based on an analysis of experimental data, the effects of temperature on the hyperelastic behaviors of both natural rubber and filled rubber, with different mass fractions of carbon black, were studied. The regulation of stress and strain of natural rubber and filled rubber with temperature was revealed. In addition, an eight-chain model that can reasonably characterize the experimental data at different temperatures was proved. An explicit temperature-dependent constitutive model was developed based on the Arruda-Boyce model to describe the stress–strain response of filled rubber in a relatively large temperature range. Meanwhile, it was proved that the model can predict the effect of temperature on the hyperelastic behavior of filled rubber. Finally, the improved Arruda-Boyce model was used to obtain the material parameters and was then successfully applied to finite element analysis (FEA), which showed that the model has high application value. In addition, the model had a simple form and could be conveniently applied in related performance test of actual production or finite element analysis.

Finite Element Calculation of Sintering Deformation Using Limited Experimental Data

2008 ◽  
Vol 606 ◽  
pp. 103-118 ◽  
Author(s):  
Jing Zhe Pan ◽  
Ruo Yu Huang
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Ceramic Powder ◽  
Material Model ◽  
Element Analysis ◽  
Ceramic Components ◽  
On Line ◽  
Element Method

Predicting the sintering deformation of ceramic powder compacts is very important to manufactures of ceramic components. In theory the finite element method can be used to calculate the sintering deformation. In practice the method has not been used very often by the industry for a very simple reason – it is more expensive to obtain the material data required in a finite element analysis than it is to develop a product through trial and error. A finite element analysis of sintering deformation requires the shear and bulk viscosities of the powder compact. The viscosities are strong functions of temperature, density and grain-size, all of which change dramatically in the sintering process. There are two ways to establish the dependence of the viscosities on the microstructure: (a) by using a material model and (b) by fitting the experimental data. The materials models differ from each other widely and it can be difficult to know which one to use. On the other hand, obtaining fitting functions is very time consuming. To overcome this difficulty, Pan and his co-workers developed a reduced finite element method (Kiani et. al. J. Eur. Ceram. Soc., 2007, 27, 2377-2383; Huang and Pan, J. Eur. Ceram. Soc., available on line, 2008) which does not require the viscosities; rather the densification data (density as function of time) is used to predict sintering deformation. This paper provides an overview of the reduced method and a series of case studies.

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