Assessment of Different Steel Material Characteristics on Shear Links Performance

2019 ◽  
Vol 1154 ◽  
pp. 150-160
Author(s):  
Sara Ansari ◽  
Javad Tashakori ◽  
Javad Razzaghi
Keyword(s):  
Strain Hardening ◽  
Local Buckling ◽  
Cyclic Stress ◽  
Inelastic Behavior ◽  
Plastic Rotation ◽  
Material Characteristics ◽  
Steel Material ◽  
Steel Grades ◽  
Element Approach ◽  
Shear Links

The inelastic behavior of shear links depends on their material ductility. In order to investigate the effect of cyclic characteristics of steel on shear links behavior, five experimental links constructed of various steel grades are modeled by finite element approach. These models are verified using experimental shear links results. Moreover, cyclic stress-strain material curve is used for simulating links behavior and the models can simulate strength degradation of flange and web local buckling appropriately. The overstrength and plastic rotation of the links are modified due to the influence of test setup configuration once the buckling occurs. It can be concluded that the links material characteristics can affect the overstrength and plastic rotation. In this study, the various strain hardening of different grades of steel are evaluated and the amplitudes of strain which can simulate strain hardening of links are determined for five materials.

Effective factors in achieving an accurate finite element simulation of shear links

2019 ◽  
Vol 11 (1) ◽  
pp. 60-70
Author(s):  
Javad Tashakori ◽  
Sara Ansari ◽  
Javad Razzaghi
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Strain Hardening ◽  
Local Buckling ◽  
Strain Curve ◽  
Element Model ◽  
Experimental Results ◽  
Finite Element Models ◽  
Content Type ◽  
Shear Links

Purpose During severe earthquakes, the inelastic energy dissipation of eccentrically braced frame system depends on shear links performance. A finite element model can predict links behavior appropriately if the factors causing large discrepancies are recognized and modified. The paper aims to discuss this issue. Design/methodology/approach In order to achieve this, the present paper discusses the cyclic response of five types of shear links constructed of various steel grades that ranged from 100 to 485 MPa yield strength. Finite element models are verified by experimental results. As these links have substantial differences in strain hardening of steel materials, different amplitudes of material stress‒strain curve loops are used to specify the level of strain hardening in finite element models. Findings The solid and shell elements in ABAQUS element factory can predict local buckling perfectly, and the computation cost of the former is significantly more than the latter. However, one of the solid elements can predict plastic deformation accurately if no local buckling emerges. The axial constraint of test setup equipment can cause excessive plastic deformation in comparison to the link plastic rotation capacity. Furthermore, some shear links with middle stiffeners can reach inaccurate high plastic rotations due to lack of defining fracture criteria in finite element models. Originality/value In this study, some resources of discrepancies between experimental results and finite element models are mentioned to ensure the reliable use of finite element models.

The New Theory of Plasticity, Strain Hardening, and Creep, and the Testing of the Inelastic Behavior of Metals

1933 ◽  
Vol 1 (4) ◽  
pp. 151-155
Author(s):  
H. Hencky
Keyword(s):  
Strain Hardening ◽  
Elastic Energy ◽  
Inelastic Behavior ◽  
Analytical Treatment ◽  
Very Old ◽  
Theory Of Plasticity

Abstract The knowledge of the inelastic behavior of metals has experienced considerable growth in the last few years. To draw all the advantages possible from the experiments, frequently very difficult, an effort has been made to bring the entire development under some dominating physical ideas. These ideas are in fact very old, and deal mainly with the proper conception of the hidden elastic energy that is responsible for the statical component of the strain hardening. The analytical treatment of the inelastic behavior gives promise of being valuable not only in the testing of materials, but even for the designer of machines used in the forming of metals.

Mesodamage Evolution in Polycrystals

2005 ◽  
Vol 127 (2) ◽  
pp. 214-221 ◽  
Author(s):  
M. Chadli ◽  
A. Abdul-Latif
Keyword(s):  
Fatigue Life ◽  
Micromechanical Model ◽  
Small Strain ◽  
Cyclic Stress ◽  
Damage Variable ◽  
Thermodynamic Force ◽  
Inelastic Behavior ◽  
Loading Paths ◽  
Localized Plastic Deformation ◽  
Phase Angles

A micromechanical model of damaged elasto-inelastic behavior is proposed to predict the plastic fatigue life for fcc metallic polycrystals under multiaxial loading paths. This model is expressed in the time-dependent plasticity for a small strain assumption. In order to generalize and then to increase the model applicability (with respect to other works of the author) in describing the cyclic stress-strain evolution during plastic fatigue, it is therefore assumed that a damage variable initiates and then evolves at the grain level where the phenomenon of the localized plastic deformation occurs. The associated thermodynamic force of the damage variable is determined as a total granular energy (elastic and inelastic). The transition of the elastic strain from the single to the polycrystal, which is classically performed by averaging procedures in this type of modeling, is modified due to the coupling of such a strain with damage. The developed model is tested under different multiaxial cyclic loading situations (tension-compression and tension-torsion with different out-of-phase angles). The effects the loading paths and the grains aggregate type on the fatigue life are appropriately investigated. It is demonstrated that the model can correctly describe the overall and local damaged behavior of polycrystals.

scholarly journals ANALYSIS OF A CANTILEVER COLUMN SUBJECTED TO CYCLIC LOADING

2020 ◽  
Vol 1 (2) ◽  
pp. 38-39
Author(s):  
Tran Tuan Nam
Keyword(s):  
Cyclic Loading ◽  
Local Buckling ◽  
Hysteretic Behavior ◽  
Steel Columns ◽  
Buckling Behavior ◽  
Column Wall ◽  
Component Test ◽  
Element Approach ◽  
Hinge Zone ◽  
Analytical Result

In a seismic incident, the structural steel columns are commonly damaged with local buckling formulation at either the top or bottom ends. This study analyzes and simulates the hysteretic behavior of a hollow square steel column under cyclic loading by adopting the fiber-element approach. This method discretizes the hinge zone into a series of fibers and considers buckling behavior of those fibers along the column wall. The analytical result was achieved in good agreement with the component test.

Damage Inspection and Assessment on a Transmission Angle Tower in Coastal Areas

2013 ◽  
Vol 671-674 ◽  
pp. 650-654
Author(s):  
Peng Yun Li ◽  
Bo Chen ◽  
Yu Zhou Sun
Keyword(s):  
Structural Model ◽  
Wind Loading ◽  
Transmission Tower ◽  
Line System ◽  
Steel Material ◽  
Transmission Angle ◽  
Commercial Package ◽  
Loading Effects ◽  
Structural Responses ◽  
Element Approach

The field inspection and safety assessment of a transmission angle tower are actively carried out in this study. The field measurement and inspection are firstly introduced and then the structural model is constructed based on finite element approach with the aiding of commercial package ANSYS. The equation of motion of the transmission tower-line system is established for numerical analysis. The gravity, base settlement and dynamic wind loading are applied on the tower to examine the structural responses. The deformation and stresses distribution of the transmission angle tower are computed to explore the damage reasons. The made observations indicate that the peak stresses of some members are large than the permitted yielding stresses of steel material. The damage event is induced by coupling loading effects

Effects of Stress–Strain Characteristics on Local Buckling of X80 Pipe Subjected to Strike-Slip Fault Movement

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Xiaoben Liu ◽  
Hong Zhang ◽  
Onyekachi Ndubuaku ◽  
Mengying Xia ◽  
J. J. Roger Cheng ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Local Buckling ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Large Strains ◽  
Fe Model ◽  
Stress Strain ◽  
Shell Elements ◽  
Steel Material ◽  
Buckling Behavior

The structural integrity of underground pipelines are subject to a major threat from permanent ground displacements when they cross active tectonic (e.g., strike-slip) faults, because of large strains potentially induced in pipes, leading to pipe buckling and possible rupture. In this paper, the buckling behavior of X80 pipe is studied numerically with an emphasis on the effects of steel stress–strain characteristics. A rigorous mechanics-based nonlinear finite element (FE) model of a buried X80 pipe crossing a strike-slip fault is developed using shell elements and nonlinear springs for the pipe and soil resistance, respectively. The pipe steel material in the FE model is characterized by a novel and versatile stress–strain relationship, which was established to successfully capture both the round-house (RH) type and the yield-plateau (YP) type stress–strain behaviors. This allows investigating the significant effects of the stress–strain characteristics, as observed in this paper, on the buckling behavior of pressurized and nonpressurized pipes.

scholarly journals A Numerical Investigation Into Ultimate Strength and Buckling Behavior of Locally Corroded Steel Tubular Members

2012 ◽  
Author(s):  
Mohammad Reza Khedmati ◽  
Masoud Nazari ◽  
Amir Foad Khalaj
Keyword(s):  
Ultimate Strength ◽  
Local Buckling ◽  
Finite Element Approach ◽  
Buckling Behavior ◽  
Compressive Loads ◽  
Length Width ◽  
Element Approach ◽  
Strength And Deformation ◽  
Semi Empirical ◽  
Strength Effect

In this paper an investigation is presented based on numerical modeling of locally corroded tubular members. A parametric finite element approach was used in order to simulate behavior of damaged members under axial compressive loads. The results were then examined against an available experimental test. Validated models are used to derive a semi-empirical formula for predicting ultimate strength of locally damaged tubes as a function of corrosion dimensions. Geometry of corrosion can be defined by its depth, length, width and location of damage along the tube. In this study it is focused on the effect of some parameters that have not been addressed yet by other researchers, e.g. slenderness of the tubes and location of patch corrosion. It was found that location of corrosion has great effect on reduction of ultimate strength. Effect of corrosion geometry was also studied and it was shown that tubes with different corrosion dimensions show different behaviors under compressive loads. In cases with severe corrosion damages, the occurrence of local buckling plays an important role on reduction of ultimate strength and deformation of damaged region. The effect of tubular slenderness on behavior of axially compressed tubes was also studied and formulated.

Computer Simulation of Transformation during TRIP Steel Rod Drawing

2016 ◽  
Vol 716 ◽  
pp. 620-631 ◽  
Author(s):  
Dmitriy Konstantinov ◽  
Krzysztof Bzowski ◽  
Aleksey Korchunov ◽  
Maciej Pietrzyk ◽  
Roman Kuziak
Keyword(s):  
Computer Simulation ◽  
Strain Hardening ◽  
Trip Steel ◽  
Retained Austenite ◽  
Simulation Method ◽  
High Plasticity ◽  
Calculation Time ◽  
Steel Microstructure ◽  
Steel Grades ◽  
Simulation Results

Axis pins, shafts and other rod-like parts are some of the main components of units and machines. They are manufactured from steel rods ranging from 7 to 60 mm in diameter after single-pass drawing. Unalloyed carbon steel grades are generally used to produce these items. TRIP steels application is advantageous in terms of achieving new properties when manufacturing steel rods. The initial billet size, the need to take account a transformation in TRIP steel microstructure and a great number of analysed technological conditions make it challenging to apply new materials into rod drawing process. The research aim is to explore the stress-strain state during rod drawing of steel TRIP700. Modified multiscale computer simulation method has been applied. The simulation method takes into account transformation of retained austenite into martensite during plastic deformation. Decreasing of the computational resource intensity and calculation time has been achieved by application of concept of Statistically Similar Representative Volume Element (SSRVE). Comparative analysis of rod drawing micromodels with and without the TRIP-effect simulation has been performed. The analysis showed that a values of equivalent strains in the deformation zone of a TRIP-ignored micromodel was three-four times lower than in a TRIP-factored micromodel. The analysis of simulation results has revealed that, due to a wide contact area with adjacent grains and interaction between microstructure elements, more intensive martensitic transformation occurred within larger grains of retained austenite. The micromodel shown that position and orientation of grains in the deformed TRIP steel microstructure are some of the factors that predetermine transformation of retained austenite. On the basis of simulation results recommendations on preparation of rod drawing conditions have been developed. Developed technological conditions provides ability to obtain: high-plasticity characteristics and high potential strain-hardening capability during exploitation of a future part; maximum strengthening throughout the cross-section of the rod after drawing; high strain-hardening of the surface layer only. The using of SSRVE concept reduced a number of elements within the micromodel in 20 times, while it lowered the calculation time in 16 times.

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