An Elastic-Plastic Stress Analysis of the Specimen Used in the Torsional Kolsky Bar

1980 ◽  
Vol 47 (2) ◽  
pp. 278-282 ◽  
Author(s):  
Eric K. C. Leung
Keyword(s):  
Numerical Solutions ◽  
Elastic Stress ◽  
Dynamic Testing ◽  
Kolsky Bar ◽  
The Finite Element Method ◽  
Governing Equations ◽  
Elastic Plastic ◽  
Applied Torque ◽  
Torsional Kolsky Bar ◽  
Tubular Specimens

This paper examines the stress concentration, the yielding process, and the growth of the elastic-plastic boundary as a function of applied torque in tubular specimens with a short thin-walled section. Although the analysis is entirely quasi-static, it can, under the proper circumstances, be applied to the deformation of short specimens as generally used for dynamic testing in the torsional Kolsky bar. In the analysis, the governing equations for both elastic and elastic-plastic analyses are presented, the latter taking into account work hardening. Numerical solutions of these equations employ the finite-element method. The elastic stress distribution in the specimen and the elastic-plastic enclaves are presented for various loading stages.

Modeling the Multiphysics Wrinkling Instability of Ionic Polymer Composite Plates for Artificial Muscle Applications

2016 ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Polymer Composite ◽  
Large Deflection ◽  
Numerical Solutions ◽  
Artificial Muscle ◽  
Composite Plates ◽  
The Finite Element Method ◽  
Governing Equations ◽  
Ionic Polymer

In this paper we first present the derivation of the governing equations that describe the multiphysics behavior of Ionic Polymer Composite Plates (IPMC). This is done in a manner that accounts for their non-linear large deflection deformation under the influence of mechanical, electrical, thermal and multicomponent mass transport fields. We subsequently present numerical solutions of the system of these equations via the use of the finite element method for a case of a specific rectangular plate. Emphasis is given in identifying the multiphysics based wrinkling instability behavior that manifest near the corners of these plates due to multiphysics stimuli.

On the Determination of Effective Elastic-Plastic Properties for the Equivalent Solid Plate Analysis of Tube Sheets

1974 ◽  
Vol 96 (3) ◽  
pp. 220-227 ◽  
Author(s):  
T. Slot ◽  
T. R. Branca
Keyword(s):  
Numerical Solutions ◽  
Solid Material ◽  
The Finite Element Method ◽  
Plastic Properties ◽  
Perforated Plates ◽  
Elastic Plastic ◽  
Solid Plate ◽  
Plate Analysis ◽  
Metal Properties

Practical procedures are described for the evaluation of effective material properties for use in elastic-plastic analyses of perforated plates involving the equivalent solid plate approach. The finite-element method is used to generate numerical solutions that permit these properties to be determined for a given penetration pattern and given base metal properties. An example is treated for the triangular penetration pattern. The results are illustrative of the anisotropy of the equivalent solid material.

Dynamic Responses of a Self-Moving Precision Positioning Stage Impacted by a Spring-Mounted Piezoelectric Actuator

2003 ◽  
Vol 125 (4) ◽  
pp. 658-661 ◽  
Author(s):  
Rong-Fong Fung, ◽  
Yung-Tien Liu, ◽  
Tai-Kun Huang, ◽  
Toshiro Higuchi,
Keyword(s):  
Piezoelectric Actuator ◽  
Numerical Solutions ◽  
High Accuracy ◽  
The Self ◽  
Dynamic Responses ◽  
Nanometer Scale ◽  
The Finite Element Method ◽  
Governing Equations ◽  
Precision Positioning ◽  
Positioning Stage

The piezoelectric actuator (PA) has been used for precision positioning from micrometer down to nanometer scale. In this paper, a spring-mounted PA is designed to achieve a high accuracy and self-moving ability in precision positioning motion. The contact force between the hammer and the self-moving stage, and the friction force of Leuven’s model caused between the grinded groove and the self-moving stage are considered. The governing equations of the system are formulated by using the finite-element method (FEM). The numerical solutions are provided to compare with the experimental results, and demonstrate the well agreement of the present theoretical formulations.

Elastic stress concentration factors in finite plates under tensile loads

1966 ◽  
Vol 1 (4) ◽  
pp. 306-312 ◽  
Author(s):  
S M Ibrahim ◽  
H McCallion
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Numerical Solutions ◽  
Elastic Stress ◽  
Governing Equations ◽  
Uniaxial Load ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors

New results for stress concentration factors at notches, fillets and circular holes in plates under uniaxial load are presented. These stress concentration factors have been obtained from numerical solutions of the governing equations for elastic stress distribution and are compared with experimental and theoretical factors published by other workers. The generality of the method used is indicated in the solutions obtained for finite plates with a number of holes and for a plate with a hole and notches.

Thermal Post-Buckling Analysis of Functionally Graded Composite Plates with Nonlinear Aerodynamic Forces

2010 ◽  
Vol 123-125 ◽  
pp. 280-283
Author(s):  
Chang Yull Lee ◽  
Ji Hwan Kim
Keyword(s):  
Material Properties ◽  
Numerical Solutions ◽  
Virtual Work ◽  
Shear Deformation Theory ◽  
Composite Plates ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Governing Equations ◽  
Functionally Graded Composite ◽  
Post Buckling

The post-buckling of the functionally graded composite plate under thermal environment with aerodynamic loading is studied. The structural model has three layers with ceramic, FGM and metal, respectively. The outer layers of the sandwich plate are different homogeneous and isotropic material properties for ceramic and metal. Whereas the core is FGM layer, material properties vary continuously from one interface to the other in the thickness direction according to a simple power law distribution in terms of the volume fractions. Governing equations are derived by using the principle of virtual work and numerical solutions are solved through a finite element method. The first-order shear deformation theory and von-Karman strain-displacement relations are based to derive governing equations of the plate. Aerodynamic effects are dealt by adopting nonlinear third-order piston theory for structural and aerodynamic nonlinearity. The Newton-Raphson iterative method applied for solving the nonlinear equations of the thermal post-buckling analysis

Elastic-Plastic FEM Analysis of Deformations of a Cylinder Subjected to Severe Uniaxial and Bilateral Compression by Flat Plates

1991 ◽  
Author(s):  
M. Gotoh ◽  
Y. Shibata
Keyword(s):  
Compressive Force ◽  
Fem Analysis ◽  
Plane Stress State ◽  
Deformation Pattern ◽  
Lateral Compression ◽  
The Finite Element Method ◽  
Ring Plane ◽  
Flat Plates ◽  
Elastic Plastic ◽  
Plastic Forming

Abstract Uni-lateral and bi-lateral elastic-plastic compressions of a circular cylinder with three different wall thicknesses by flat plates are numerically analysed by the Finite Element Method (FEM). J2-flow theory (J2F), and J2-Gotoh’s corner theory (J2G) which was previously proposed by one of the authors are used as the constitutive equations. In the case of uni-lateral compression, the cylinder is compressed up to a completely flattened shape, which is considered a kind of plastic forming processes. The deformed shapes and the compressive force are predicted better by J2G than by J2F. The spring-back behaviours are also analysed by imposing unloading process during deformation. The deformation process in the compression of a ring (plane stress state) and a spherical shell (axi-symmetric state) is also analysed. In the case of bi-lateral compression, the process is considered a kind of square-tube forming. In its final stage, the cylinder deforms into a completely unexpected shape which could be thought of as a square tube reinforced with ribs. The J2G allows the process to proceed at a lower compressive force than that for J2F. The effect of n-value (the strain-hardedning exponent) on the deformation pattern is also discussed.

scholarly journals Data Driven Solutions and Discoveries in Mechanics Using Physics Informed Neural Network

2020 ◽  
Author(s):  
Qi Zhang ◽  
Yilin Chen ◽  
Ziyi Yang
Keyword(s):  
Neural Network ◽  
Differential Equations ◽  
Automatic Differentiation ◽  
Numerical Solutions ◽  
Data Driven ◽  
Attractive Alternative ◽  
The Finite Element Method ◽  
The Neural Network ◽  
Engineering Problems ◽  
Free Parameters

Deep learning has achieved remarkable success in diverse computer science applications, however, its use in other traditional engineering fields has emerged only recently. In this project, we solved several mechanics problems governed by differential equations, using physics informed neural networks (PINN). The PINN embeds the differential equations into the loss of the neural network using automatic differentiation. We present our developments in the context of solving two main classes of problems: data-driven solutions and data-driven discoveries, and we compare the results with either analytical solutions or numerical solutions using the finite element method. The remarkable achievements of the PINN model shown in this report suggest the bright prospect of the physics-informed surrogate models that are fully differentiable with respect to all input coordinates and free parameters. More broadly, this study shows that PINN provides an attractive alternative to solve traditional engineering problems.

Reinforcement Calculated Method Based on Disease Model of DongFu Bridge

2012 ◽  
Vol 178-181 ◽  
pp. 2199-2203
Author(s):  
Peng Jun Liu
Keyword(s):  
Finite Element Method ◽  
Dynamic Testing ◽  
Disease Model ◽  
Reference Value ◽  
Original Structure ◽  
Structure Model ◽  
The Finite Element Method ◽  
Stiffness Reduction ◽  
Shear Area ◽  
Main Bridge

On the basis of the static and dynamic testing of the bridge, the original structure model and the model based on stiffness reduction of Dongfu Bridge were analyzed and calculated with the finite element method. The main problem that the anti-shear area of the section in the middle pivot position is not enough is found. On the basis of combination of the passive and active reinforcement styles, a reasonable and feasible reinforcement plan on the girder beam of the main bridge is raised. These conclusions have an important reference value on the bridge reinforcement.

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