scholarly journals Non-Linear Buckling Analysis of Axially Loaded Column with Non-Prismatic I-Section

2019 ◽  
Vol 5 (3) ◽  
pp. 263
Author(s):  
Adrian Pramudita Dharma ◽  
Bambang Suryoatmono
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Cross Sections ◽  
Plastic Material ◽  
Slenderness Ratio ◽  
Buckling Load ◽  
Coefficient Of Determination ◽  
Average Cross Section ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

In order to use material efficiently, non-prismatic column sections are frequently employed. Tapered-web column cross-sections are commonly used, and design guides of such sections are available. In this study, various web-and-flange-tapered column sections were analysed numerically using finite element method to obtain each buckling load assuming the material as elastic-perfectly plastic material. For each non-prismatic column, the analysis was also performed assuming the column is prismatic using average cross-section with the same length and boundary conditions. Buckling load of the prismatic columns were obtained using equation provided by AISC 360-16. This study proposes a multiplier that can be applied to the buckling load of a prismatic column with an average cross-section to acquire the buckling load of the corresponding non-prismatic column. The multiplier proposed in this study depends on three variables, namely the depth tapered ratio, width tapered ratio, and slenderness ratio of the prismatic section. The equation that uses those three variables to obtain the multiplier is obtained using regression of the finite element results with a coefficient of determination of 0.96.

Elasto-Plastic Coupled Temperature-Displacement Finite Element Analysis of Two-Dimensional Rolling-Sliding Contact With a Translating Heat Source

1991 ◽  
Vol 113 (1) ◽  
pp. 93-101 ◽  
Author(s):  
S. M. Kulkarni ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Plastic Material ◽  
Element Model ◽  
Rolling Contact ◽  
Two Dimensional ◽  
Element Analysis ◽  
Element Mesh ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The present paper, describes a transient translating elasto-plastic thermo-mechanical finite element model to study 2-D frictional rolling contact. Frictional two-dimensional contact is simulated by repeatedly translating a non-uniform thermo-mechanical distribution across the surface of an elasto-plastic half space. The half space is represented by a two dimensional finite element mesh with appropriate boundaries. Calculations are for an elastic-perfectly plastic material and the selected thermo-physical properties are assumed to be temperature independent. The paper presents temperature variations, stress and plastic strain distributions and deformations. Residual tensile stresses are observed. The magnitude and depth of these stresses depends on 1) the temperature gradients and 2) the magnitudes of the normal and tangential tractions.

A limit load solution for a thick-walled cylinder with a fully circumferential crack under axial tension

2009 ◽  
Vol 44 (6) ◽  
pp. 407-416 ◽  
Author(s):  
P J Budden ◽  
Y Lei
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Yield Criterion ◽  
Limit Load ◽  
Cylinder Wall ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic ◽  
Von Mises ◽  
Inside Radius ◽  
Walled Cylinder

Limit loads for a thick-walled cylinder with an internal or external fully circumferential surface crack under pure axial load are derived on the basis of the von Mises yield criterion. The solutions reproduce the existing thin-walled solution when the ratio between the cylinder wall thickness and the inside radius tends to zero. The solutions are compared with published finite element limit load results for an elastic–perfectly plastic material. The comparison shows that the theoretical solutions are conservative and very close to the finite element data.

A Finite Element Based Study on the Elastic-Plastic Transition Behavior in a Hemisphere in Contact With a Rigid Flat

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
S. Shankar ◽  
M. M. Mayuram
Keyword(s):  
Finite Element ◽  
Contact Area ◽  
Plastic Material ◽  
Plastic Region ◽  
Real Contact Area ◽  
Real Contact ◽  
Perfectly Plastic ◽  
The Difference ◽  
Elastic Perfectly Plastic ◽  
Green Model

An axisymmetrical hemispherical asperity in contact with a rigid flat is modeled for an elastic perfectly plastic material. The present analysis extends the work (sphere in contact with a flat plate) of Kogut–Etsion Model and Jackson–Green Model and addresses some aspects uncovered in the above models. This paper shows the critical values in the dimensionless interference ratios (ω∕ωc) for the evolution of the elastic core and the plastic region within the asperity for different Y∕E ratios. The present analysis also covers higher interference ratios, and the results are applied to show the difference in the calculation of real contact area for the entire surface with other existing models. The statistical model developed to calculate the real contact area and the contact load for the entire surfaces based on the finite element method (FEM) single asperity model with the elastic perfectly plastic assumption depends on the Y∕E ratio of the material.

Plastic Twisting of Thick-Walled Circular Ring Sectors

1956 ◽  
Vol 23 (3) ◽  
pp. 461-463
Author(s):  
W. Freiberger ◽  
W. Prager
Keyword(s):  
Stress Distribution ◽  
Plastic Flow ◽  
Cross Section ◽  
Cross Sections ◽  
Graphical Method ◽  
Plastic Material ◽  
Circular Ring ◽  
Perfectly Plastic ◽  
The Cross ◽  
Plastic Stress

Abstract The paper presents a graphical method of determining the fully plastic stress distribution in a twisted circular ring sector with hollow cross section and the warping of the cross sections of this ring in the ensuing plastic flow. The ring is assumed to consist of a rigid, perfectly plastic material.

Review and Comparison of Buckling Methodologies for ASME B&PV Code, Section III, Subsection NF Linear Piping Restraints

2016 ◽  
Author(s):  
Shrikant Nargund ◽  
Dennis K. Williams
Keyword(s):  
Finite Element ◽  
Large Deformation ◽  
Plastic Material ◽  
Slenderness Ratio ◽  
Structural Member ◽  
Buckling Load ◽  
Material Behavior ◽  
Deformation Method ◽  
Critical Buckling Load ◽  
Hexahedral Elements

Piping supports and restrains are required to follow the design requirements as mentioned in ASME B&PV Code, Section III, Subsection NF. One of the requirements indicates the necessity of calculating the critical buckling stresses for the members that are subjected to a compressive loading. This paper discusses the prescribed requirements in the Code that specifically address the considerations of the stability and buckling load capacities of linear piping restraints (i.e., struts). The finite element modeling of various strut geometries and the results of the buckling analyses of a slender (slenderness ratio Kl/r greater than or equal to 100) structural members using various finite element solution techniques are presented herein. Specifically, three types of finite element analysis are conducted in an effort to define the critical buckling load for the subject structural member, and include the traditional linear (Eigen value) Euler method; the nonlinear, second order large deformation method; and finally, the nonlinear large deformation method that incorporates nonlinear elastic-plastic material behavior. These techniques are employed for a hollow cylindrical structural member (i.e., a strut assembly) with varying cross sections along its length. Finite element model consists of three dimensional hexahedral elements in combination with beam elements for the general purpose a finite element solver ANSYS. The critical buckling load is calculated in each case, thereby predicting the load at which instability will occur in the structural member. The results obtained from the aforementioned techniques are then compared both numerically and qualitatively with an appropriate explanation of the purpose and usefulness of each particular result with respect to the intent of the ASME B&PV Code, Section III, Subsection NF requirements. The results show significant variations (as expected) based on differences in the assumptions and techniques employed in the respective analyses.

NONLINEAR STABILITY ANALYSIS OF THIN-WALLED FRAMES USING UL–ESA FORMULATION

2004 ◽  
Vol 04 (01) ◽  
pp. 45-67 ◽  
Author(s):  
GORAN TURKALJ ◽  
JOSIP BRNIĆ
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Displacement Field ◽  
Plastic Material ◽  
Plastic Hinge ◽  
Element Formulation ◽  
Nonlinear Stability Analysis ◽  
Perfectly Plastic ◽  
Straight Beam ◽  
Thin Walled

This work presents a one-dimensional finite element formulation for nonlinear analysis of spaced framed structures with thin-walled cross-sections. Within the framework of updated Lagrangian formulation, the nonlinear displacement field of thin-walled cross-sections, which accounts for restrained warping as well as the second-order displacement terms due to large rotations, the equations of equilibrium are firstly derived for a straight beam element. Due to the nonlinear displacement field, the geometric potential of semitangential moment is obtained for both the torsion and bending moments. In such a way, the joint moment equilibrium conditions of adjacent non-collinear elements are ensured. Force recovering is performed according to the external stiffness approach. Material nonlinearity is introduced for an elastic-perfectly plastic material through the plastic hinge formation at finite element ends and for this a corresponding plastic reduction matrix is determined. The interaction of element forces at the hinge and the possibility of elastic unloading are taken into account. The effectiveness of the numerical algorithm discussed is validated through the test problem.

Use of measured imperfections to predict the buckling of axially loaded cylindrical shells

1983 ◽  
Vol 10 (4) ◽  
pp. 662-669 ◽  
Author(s):  
R. B. Pinkney ◽  
M. J. Stephens ◽  
D. W. Murray ◽  
G. L. Kulak
Keyword(s):  
Finite Element ◽  
Structural Engineering ◽  
Plastic Material ◽  
Cylindrical Shells ◽  
Flow Rule ◽  
Initial Imperfections ◽  
Perfectly Plastic ◽  
Axially Loaded ◽  
Elastic Perfectly Plastic ◽  
Element Technique

Analyses to predict inelastic buckling of axially loaded thin cylindrical shells are carried out using the finite element technique. The analyses use a bilinear elastic–perfectly plastic material response based upon the associated flow rule of plasticity. Nonlinear geometric effects, combined with initial imperfections, produce load-deflection curves with descending branches for which the limit points are imperfection sensitive.Results from these analyses are compared with two tests of axially loaded cylinders fabricated from 10-gauge (3.4-mm) and 5-mm plate and approximately 1525 mm in diameter. These tests were carried out in the Structural Engineering Laboratory at the University of Alberta. A rational technique for using measured imperfections to obtain effective initial imperfections for use in the analyses is investigated, and is shown to result in accurate predictions of ultimate load. Keywords: shell, cylinder, buckling, plastic, imperfection, axial load, finite element, nonlinear analysis.

Finite Element Based Unloading of an Elastic Plastic Spherical Stick Contact for Varying Tangent Modulus and Hardening Rule

2013 ◽  
Vol 1 (1) ◽  
pp. 13-32
Author(s):  
Biplab Chatterjee ◽  
Prasanta Sahoo
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Kinematic Hardening ◽  
Tangent Modulus ◽  
Isotropic Hardening ◽  
Finite Element Software ◽  
Perfectly Plastic ◽  
Hardening Models ◽  
Qualitative Similarity ◽  
Elastic Perfectly Plastic

Loading-unloading behavior of a deformable sphere with a rigid flat under full stick contact condition is investigated for varying strain hardening. The study considers various tangent modulus using the finite element software ANSYS. Both the bilinear kinematic hardening and isotropic hardening models are considered. Numerical simulation reveals the qualitative similarity between kinematic and isotropic hardening regarding the variation of interfacial parameters during loading-unloading for various tangent modulus. It is found that the material with kinematic hardening dissipates more energy than the material with isotropic hardening during unloading. However for elastic perfectly plastic material, the loading-unloading behavior is insensitive to hardening model.

scholarly journals Nonlinear Finite Element Analysis of Fiber Reinforced Concrete Slabs

2021 ◽  
Vol 39 (3A) ◽  
pp. 426-439
Author(s):  
Saad A. Al-Taan ◽  
Ayad A. Abdul-Razzak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Plastic Material ◽  
Fiber Reinforced Concrete ◽  
Concrete Slabs ◽  
Element Analysis ◽  
Perfectly Plastic ◽  
Reinforced Concrete Slabs ◽  
Elastic Perfectly Plastic

This paper presents a study on the behavior of fiber reinforced concrete slabsusing finite element analysis. A previously published finite element program is used for the nonlinear analysis by including the steel fiber concrete properties. Concrete is represented by degenerated quadratic thick shell element, which is the general shear deformable eight node serendipity element, and the thickness is divided into layers. An elastic perfectly plastic and strain hardening plasticity approach are used to model the compression behavior of concrete.The reinforcing bars were smeared within the concrete layers and assumed as either an elastic perfectly plastic material or as an elastic-plastic material with linear strain hardening. Cracks initiation is predicted using a tensile strength criterion. The tension stiffening effect of the steel fibers is simulated using a descending parabolic stress degradation function, which is based on the fracture energy concept. The effect of cracking in reducing the shear modulus and the compressive strength of concrete parallel to the crack direction is considered. The numerical results showedgood agreement with published experimental results for two fibrous reinforced concrete slabs.

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