Investigation of Effect of Phase Transformations on Mechanical Behavior of AISI 1010 Steel in Laser Forming

2005 ◽  
Vol 129 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Yajun Fan ◽  
Zhishang Yang ◽  
Peng Cheng ◽  
Keith Egland ◽  
Lawrence Yao
Keyword(s):  
Phase Transformation ◽  
Phase Transformations ◽  
Volume Fraction ◽  
Constitutive Relationship ◽  
Laser Forming ◽  
Transformation Kinetic ◽  
Forming Process ◽  
Element Analysis ◽  
Relationship Of ◽  
Phase Transformation Kinetic

In laser forming, phase transformations in the heat affected zone take place under steep cooling rates and temperature gradients, and have a significant affect on the laser forming process and final mechanical properties of products. In this work, phase transformations during laser forming of AISI 1010 steel are experimentally and numerically investigated and the transient volume fraction of each available phase is calculated by coupling the thermal history from finite element analysis with a phase transformation kinetic model. Consequently, the flow stresses of material are obtained from the constitutive relationship of the phases, and the laser forming process is modeled considering the effect of work hardening, recrystallization and phase transformation. A series of carefully controlled experiments are also conducted to validate the theoretically predicted results.

Simulation Investigation the Effect of Heating-Lines on Tensile Mechanical Properties of Sheet Metal after Laser Scanning

2011 ◽  
Vol 314-316 ◽  
pp. 331-336 ◽  
Author(s):  
Wen Jiao Dan ◽  
Wei Gang Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Sheet Metal ◽  
Mechanical Model ◽  
Laser Scanning ◽  
Constitutive Relationship ◽  
Transformation Kinetic ◽  
Element Analysis ◽  
Relationship Of ◽  
Phase Transformation Kinetic

In this study, tensional mechanical properties of sheet metal with heating-lines after laser scanning are investigated based on the thermal-microstructure-mechanical model. The phase transformations, during laser scanning of sheet metal, are calculated by coupling the thermal history from finite element analysis with a phase transformation kinetic model. The flow stresses of material are obtained from the constitutive relationship of the phases based on the mixture strain hardening laws. The results show that the influence of the heating-lines number on tensional mechanical properties of material is obvious. The mechanical properties are related to the distribution of microstructure in heat affected zone after laser scanning.

Affected Characteristics Analysis of the Pulsed Laser Forming of Metal Sheet

2008 ◽  
Vol 375-376 ◽  
pp. 333-337
Author(s):  
Li Jun Yang ◽  
Yang Wang
Keyword(s):  
Laser Beam ◽  
Pulsed Laser ◽  
Metal Sheet ◽  
Grain Structure ◽  
Experimental Result ◽  
Laser Forming ◽  
Forming Process ◽  
Grain Orientations ◽  
Characteristics Analysis ◽  
Relationship Of

Laser forming of metal sheet is a forming technology of sheet without a die that the sheet is deformed by internal thermal stress induced by partially irradiation of a laser beam. In this paper, the bending behavior of common stainless steel 1Cr18Ni9 sheet is studied after being irradiated by straight line with a Nd:YAG pulsed laser beam. The aim of the investigation is to find out the relationship of the physical behaviors of heat affected zone (HAZ) with the pulse parameters of the laser. Through the analysis of the fundamental theory of pulsed laser affected, this paper shows the affected characteristics of metal sheet with pulsed laser forming. The results show that the microstructure of HAZ of pulsed laser scanned is layered, and the micro-hardness is improved than that in matrix. The microstructures show that the deformed grain structure is inhomogeneous, that caused the grain sizes and grain orientations in HAZ to become different. By qualitative analysis of experimental result, the conclusion obtained may provide basis for theoretical investigation and possible industrial application of laser forming process in the future.

Study on Mechanism of L-Shaped Concrete-Filled Steel Tubular Columns Subjected to Axial Compression

2012 ◽  
Vol 476-478 ◽  
pp. 2463-2468 ◽  
Author(s):  
Ji Cheng Zhang ◽  
Jun Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Axial Compression ◽  
Constitutive Relations ◽  
Steel Tube ◽  
Constitutive Relationship ◽  
Steel Tubes ◽  
Element Analysis ◽  
Relationship Of ◽  
Deformation Relationship

In this paper, a constitutive relationship of the concrete core restrained by L-Shaped steel tube is put forward based on referring to the constitutive relations of core concrete in concrete-filled square steel tube columns, which takes the restraint of steel tube to concrete as an equivalent confinable effect coefficient . Load-deformation relationship of L-Shaped concrete-filled steel tubular column subjected to axial compression is analyzed by finite element analysis (using ABAQUS software). The predicted load versus deformation relationship cures are in good agreement with those of tests based on the finite element analysis, loads carried by steel tubes and concrete respectively during the loading process, as well as interactions between them are analyzed. Finally, influences of length-width ratio and width-thickness ratio on the interaction between steel tubes and concrete are investigated.

scholarly journals Nonlinear Mechanics Study of Concrete T-beam Bridge With Cracking Damage Based on Numerical Simulation

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Numerical Simulation ◽  
Constitutive Relationship ◽  
Plastic State ◽  
Nonlinear Mechanics ◽  
Element Analysis ◽  
Structural Rigidity ◽  
Beam Bridge ◽  
Relationship Of ◽  
T Beam ◽  
Selection Of

The cracking damage of concrete bridge will seriously affect the overall safety of a structure. In this study, based on the numerical simulation, finite element analysis was carried out on the concrete T beam through the ANSYS software, and the selection of elements and the constitutive relationship of materials in the numerical simulation were introduced. It was found from the results of numerical simulation that the cracks of T beam continued to develop under the action of load, the concrete entered the plastic state from the elastic state and the mid-span deflection increased with the increase of load. In the case of the change of cracks, the larger the crack height, the larger the crack range of the beam. With the increase of load, the structural rigidity continued to degenerate, and the compressive stress of the concrete also increased. The research in this paper proves the validity of numerical simulation in the study of nonlinear mechanics of beam bridge and also makes some contributions to the study of crack damage of beam bridge.

Powdering in Coating Layer of Galvannealed Nb-Ti Free Extra Low Carbon Steel Sheet

2007 ◽  
Vol 345-346 ◽  
pp. 1089-1092
Author(s):  
S.I. Kim ◽  
D.J. Paik ◽  
Shi Hoon Choi ◽  
D.W. Kim ◽  
Y.C. Yang ◽  
...  
Keyword(s):  
Fracture Behavior ◽  
Volume Fraction ◽  
Coating Layer ◽  
Low Carbon Steel ◽  
Bending Test ◽  
Low Carbon ◽  
Forming Process ◽  
Element Analysis ◽  
Steel Sheets ◽  
Hardness Variation

We have studied the fracture behavior of coating layer when low and high alloying galvannealed (GA) steels are subject to forming process. To understand better powdering features in the coating layer of the steel sheets, we carried out V-bending test and a series of finite element analysis which simulates damage characteristics in the coating layer. Results showed that the powdering behavior in the coating is significantly affected by the soundness and volume fraction of phases in the coating layer. The hardness variation of coating layers attributed to different phases leads to different deformation behavior of the coating layer itself.

A Computational Model for Phase Transformation-Temperature-Distortion Coupling of AISI 5120 Steel

2006 ◽  
Vol 118 ◽  
pp. 387-392 ◽  
Author(s):  
Seok Jae Lee ◽  
Young Kook Lee
Keyword(s):  
Heat Transfer ◽  
Phase Transformation ◽  
Kinetic Models ◽  
Transformation Temperature ◽  
Volume Fraction ◽  
Coupled Model ◽  
Avrami Equation ◽  
Transformation Kinetic ◽  
Phase Transformation Temperature ◽  
Finite Element Software

A coupled model for predicting phase transformation, temperature, and distortion of AISI 5120 steel occurring during heat treatment process has been developed. The phase transformation kinetic models were made using Johnson-Mehl-Avrami equation and the additivity rule based on theoretical thermodynamic model and experimental dilatometric data. Especially, the transformation strains measured during cooling were converted to the volume fraction of each phase for the kinetic models using a relation between transformation strain and atomic volume change. The heat transfer coefficients in quench media were calculated by inverse method of the heat transfer equation to the measured surface temperature history. To predict the temperature and distortion accurately, the thermal and mechanical data were used as a function of temperature and each phase based on the experimental data. The coupled model for phase transformation, temperature, and distortion has been implemented in the commercial finite element software ABAQUS as user subroutines. The calculated results by the coupled model were compared with the experimental ones.

Numerical and Experimental Analysis for Large Radius Deformation of Stainless Steels by Laser Forming Process

2005 ◽  
Author(s):  
J. Pennuto ◽  
J. Choi
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Laser Forming ◽  
Bend Angle ◽  
Large Radius ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process

In an effort to develop a process free of dedicated tooling, this research seeks to study large radius deformation by laser forming. Experimental testing was conducted to determine how the laser parameters affect the single pass output bend angle as well as the additive bend angle from successive parallel, evenly spaced laser irradiations. As an extension of the previous developments, this work seeks to develop a three-dimensional model to simulate the multi-scan laser process. It is of interest to determine how sophisticated a three-dimensional case is required for sufficient agreement to experimental data. The simulated results of bending angle are compared with experimental data and suggestions for future study include the implementation of phase transformation and microstructure data within the model to account for stress development resulting from phase transformation and grain growth.

Metastable Phase Transformations in Ti-40Al-10V Alloy

1994 ◽  
Vol 364 ◽  
Author(s):  
G. Shao ◽  
P. Tsakiropoulos ◽  
A. P. Miodownik
Keyword(s):  
Phase Transformation ◽  
Phase Transformations ◽  
Volume Fraction ◽  
Metastable Phase ◽  
Equilibrium Phase ◽  
Rapid Quenching ◽  
Β Phase ◽  
Transformation Sequence ◽  
Melt Spun ◽  
Melt Spun Ribbons

AbstractThe microstructures in arc melted ingots and melt spun ribbons have been investigated by electron microscopy and thermodynamic modelling has been used to study the phase transformations. In the ingot, solidification starts with the bcc β phase and at room temperature the structure consists of B2, ωordered, γ and α2 phases. The calculated equilibrium phase transformation sequence during cooling is L → L+ β→β→β + α→β2+α → α+β2+γ → α2+γ + B2. The phase transformation sequence is dramatically changed by rapid quenching from the melt. Athermal ordered w phase is formed in metastable B2 and the α→α2 ordering process is completely suppressed in the melt spun ribbons. The volume fraction of the α precipitates is also dependent on cooling rates.

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