Analytical Modeling of Top Roller Position for Multiple Pass (3-Roller) Cylindrical Forming of Plates

2006 ◽  
Author(s):  
A. H. Gandhi ◽  
H. K. Raval
Keyword(s):  
Young’S Modulus ◽  
Analytical Model ◽  
Young's Modulus ◽  
Material Behavior ◽  
Analytical Models ◽  
Radius Of Curvature ◽  
Single Pass ◽  
Multiple Pass ◽  
Efficient Performance ◽  
Constant E

As forming of the double or multiple curvature surfaces, includes roller forming at least once in the sequential process; its efficient performance is of great importance for controlling the final product dimensions. Most efficient and economical way to produce the cylinder is to roll the plate through the roller in single pass. Literature review revels that, most of the reported analytical models for the prediction of springback were developed with the assumption of zero initial strain. However, in practice multiple pass bending is recommended to work within the power limitation of the machine and to improve the accuracy of the final product. An attempt is made to develop the analytical model for estimation of top roller position as a function of desired radius of curvature, for multiple pass 3-roller forming of cylinders, considering real material behavior. Due to the change of Young's modulus of elasticity (E) under deformation, the springback is larger than the springback calculated with constant E. Developed analytical model was modified to include the effect of change of Young's modulus during the deformation. Developed multiple pass analytical models were compared with the single pass analytical model and experiments (on pyramid type 3-roller bending machine).

Numerical Modeling of Macroscopic Behavior of Particulate Composite with Crosslinked Polymer Matrix

2011 ◽  
Vol 465 ◽  
pp. 129-132
Author(s):  
Luboš Náhlík ◽  
Bohuslav Máša ◽  
Pavel Hutař
Keyword(s):  
Young’S Modulus ◽  
Polymer Matrix ◽  
Young's Modulus ◽  
Numerical Models ◽  
Strain Curve ◽  
Particulate Composite ◽  
Material Behavior ◽  
Particulate Composites ◽  
Stress Strain ◽  
Crosslinked Polymer

Particulate composites with crosslinked polymer matrix and solid fillers are one of important classes of materials such as construction materials, high-performance engineering materials, sealants, protective organic coatings, dental materials, or solid explosives. The main focus of a present paper is an estimation of the macroscopic Young’s modulus and stress-strain behavior of a particulate composite with polymer matrix. The particulate composite with a crosslinked polymer matrix in a rubbery state filled by an alumina-based mineral filler is investigated by means of the finite element method. A hyperelastic material behavior of the matrix was modeled by the Mooney-Rivlin material model. Numerical models on the base of unit cell were developed. The numerical results obtained were compared with experimental stress-strain curve and value of initial Young’s modulus. The paper can contribute to a better understanding of the behavior and failure of particulate composites with a crosslinked polymer matrix.

Analytical and Numerical Prediction of Springback of SS/Al-Alloy Cladded Sheet in V-Bending

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Pankaj Kumar Sharma ◽  
Vijay Gautam ◽  
Atul Kumar Agrawal
Keyword(s):  
Analytical Model ◽  
Outer Layer ◽  
Numerical Models ◽  
Yield Criterion ◽  
Bending Moment ◽  
Analytical Models ◽  
Bend Angle ◽  
Radius Of Curvature ◽  
Al Alloy ◽  
First Case

Abstract The present work deals with the development of an analytical model incorporating the effects of anisotropy and strain hardening to predict the springback in V-bending of two-ply sheet metal using a punch profile radius of 15 mm and included a bend angle of 90 deg. In the analytical model, the total bending moment is determined from resulting bending stresses for two different layers arranged in parallel planes one above the other and a new radius of curvature after springback is determined by applying a negative bending moment. The two-ply sheet composed of layers of AA1050 and SS430 is characterized for its tensile properties to be used in analytical and numerical models for prediction of springback. To study the effect of each layer during bending operation, two possible cases of sheet placements during bending and springback are studied; i.e., in the first case, the inner layer is of AA1050 while the SS430 layer is the outer layer whereas in the second case it is opposite. In all the cases of springback experiments when the outer layer is of SS430, the springback values are higher than the values obtained with the specimens when the inner layer is of SS430. This could be attributed to the higher tensile strength of the stainless steel layer and the higher bending radius experienced by it. The springback behaviors are also analyzed by simulations using Hill's anisotropic yield criterion in abaqus software. The springback results obtained by simulations and analytical models are in good agreement in general; however, in some cases, discrepancy of more than 15% is observed in the analytical results when compared with the experimental results.

Design Optimization of Material Properties in a Particle-Filled Composite Material System

2008 ◽  
Author(s):  
Siva P. Gurrum ◽  
Jie-Hua Zhao ◽  
Darvin R. Edwards
Keyword(s):  
Composite Material ◽  
Young’S Modulus ◽  
Material Properties ◽  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Filler Content ◽  
Young's Modulus ◽  
Random Packing ◽  
Poisson's Ratio ◽  
Analytical Models

This work presents a methodology implementing random packing of spheres combined with commercial finite element method (FEM) software to optimize the material properties, such as Young’s modulus, Poisson’s ratio, coefficient of thermal expansion (CTE) of two-phase materials used in electronic packaging. The methodology includes an implementation of a numerical algorithm of random packing of spheres and a technique for creating conformal FEM mesh of a large aggregate of particles embedded in a medium. We explored the random packing of spheres with different diameters using particle generation algorithms coded in MATLAB. The FEM meshes were generated using MATLAB and TETGEN. After importing the nodes and elements databases into commercial FEM software ANSYS, the composite materials with spherical fillers and the polymer matrix were modeled using ANSYS. The effective Young’s modulus, Poisson’s ratio, and CTE along different axes were calculated using ANSYS by applying proper loading and boundary conditions. It was found that the composite material was virtually isotropic. The Young’s modulus and Poisson’s ratio calculated by FEM models were compared to a number of analytical solutions in the literature. For low volume fraction of filler content, the FEM results and analytical solutions agree well. However, for high volume fraction of filler content, there is some discrepancy between FEM and analytical models and also among the analytical models themselves.

Near Surface Measurement of Mechanical Properties Using Instrumented Indentation Measurements

2005 ◽  
Author(s):  
K. Farhang ◽  
L. E. Seitzman ◽  
B. Feng
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Surface Measurement ◽  
Accurate Estimation ◽  
Radius Of Curvature ◽  
Instrumented Indentation ◽  
Near Surface ◽  
Parameter Function ◽  
Two Parameter ◽  
Indentation Measurement

A two-parameter function for estimation of projected area in instrumented indentation measurement is obtained to account for indenter tip imperfection. Imperfection near indenter tip-end is modeled using a spherical function and combined with a linear function describing the edge boundary of the indenter. Through an analytical fusion technique the spherical and linear functions are combined into a single function with two unknown geometric parameters of tip radius of curvature and edge slope. Data from indentation measurement of force and displacement, using a Berkovich tip and single crystal alumina and silica samples, are implemented in the proposed area function yielding estimated values of Young’s modulus. Results were compared with that obtained from Oliver and Pharr technique for deep as well as shallow indentation regimes. The estimates for Young’s modulus were found to agree quite favorably. More importantly, in contrast to the Oliver-Pharr technique, the use of the two-parameter function resulted in a significantly more accurate estimation of Young’s modulus for shallow indentation depth of 0 to 100 nm. The error in estimation of Young’s modulus was found to be within 10 percent for indentation depths 25 nm to 50 nm and within 20 percent for indentation depths 0 to 25 nm.

scholarly journals The Analytical Approach to Evaluate the Load-Displacement Relationship of Rock Bolts

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Jianhang Chen ◽  
Shengli Yang ◽  
Hongbao Zhao ◽  
Junwen Zhang ◽  
Fulian He ◽  
...  
Keyword(s):  
Shear Strength ◽  
Young’S Modulus ◽  
Analytical Model ◽  
Load Transfer ◽  
Young's Modulus ◽  
Peak Load ◽  
Rock Bolts ◽  
Residual Shear Strength ◽  
Grouted Rock Bolts ◽  
Elastic Softening

Fully grouted rock bolts are widely used in civil engineering and mining engineering, playing a significant role in keeping the stability and safety of excavations. In this paper, the load transfer mechanism of fully grouted rock bolts was studied with an analytical model. A trilinear model was used to depict the bond-slip behaviour of the bolt/grout interface. The displacement of the confining medium was involved in this analytical model. Then, the shear stress propagation along the bolt/grout interface was analysed in the elastic, elastic-softening, elastic-softening-debonding, softening-debonding, and debonding stages. Experimental pull-out tests were used to validate this analytical model. There was a good correlation between experimental and analytical results. A parametric study was conducted to evaluate the influence of Young’s modulus of the confining medium, the shear strength of the bolt/grout interface, and the residual shear strength of the bolt/grout interface on the load transfer performance of rock bolts. The results show that increasing Young’s modulus of the confining medium was beneficial for improving the load transfer performance of rock bolts. However, once Young’s modulus of the confining medium was beyond a critical limit, it had marginal effect on the peak load of rock bolts. Furthermore, increasing the shear strength of the bolt/grout interface and the residual shear strength of the bolt/grout interface led to rising of the peak load of rock bolts. However, compared with the residual shear strength of the bolt/grout interface, increasing the shear strength of the bolt/grout interface had more apparent effect in improving the peak load of rock bolts.

On Effective Mechanical Properties of Two-Dimensional Porous Materials

2020 ◽  
Vol 12 (04) ◽  
pp. 2050040
Author(s):  
Zaoyang Guo ◽  
Lei Wang ◽  
Xiaojun Guo ◽  
Yang Chen ◽  
Leiting Dong
Keyword(s):  
Porous Materials ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Full Range ◽  
Theoretical Models ◽  
Poisson's Ratio ◽  
Analytical Models ◽  
Two Dimensional ◽  
Effective Mechanical Properties

Two-dimensional (2D) representative volume element (RVE) has been widely used to simulate the effective behaviors of the materials with aligned pores. In this paper, the anisotropy indexes are defined for the 2D RVE model to quantitatively evaluate the extent of anisotropy of the model. A normalized procedure is then proposed to compute the effective moduli of the RVE models, which can further minimize the influence of anisotropy of the RVE models. The effective Poisson’s ratio of the porous materials is challengeable to be estimated well, and few analytical models can give good predictions. The theoretical models are proposed to approach the effective Young’s modulus and the effective Poisson’s ratio of the 2D porous materials covering the full range of porosity. It is numerically validated that the theoretical models give accurate predictions for the effective Young’s modulus and Poisson’s ratio of the 2D porous materials.

scholarly journals Determination of the Young's Modulus of a TiN Thin Film by Nanoindentation: Analytical Models and FEM Simulation

2012 ◽  
Vol 10 (0) ◽  
pp. 624-629
Author(s):  
H^|^eacute;l^|^egrave;ne Issel^|^eacute; ◽  
David Mercier ◽  
Guillaume Parry ◽  
Rafael Estevez ◽  
Lionel Vignoud ◽  
...  
Keyword(s):  
Thin Film ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Fem Simulation ◽  
Analytical Models
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