A Constitutive Model and Its Identification for the Deformation Characterized by Dynamic Recovery

1997 ◽  
Vol 119 (2) ◽  
pp. 138-142 ◽  
Author(s):  
M. Zhou ◽  
M. P. Clode
Keyword(s):  
Constitutive Model ◽  
Deformation Behavior ◽  
Initial Temperature ◽  
Elevated Temperatures ◽  
Dynamic Recovery ◽  
Twist Rate ◽  
Determination Methods ◽  
Hot Torsion ◽  
Nonlinear Iteration ◽  
Good Agreement

A constitutive model is presented to characterize the deformation behavior of materials at elevated temperatures that undergo dynamic recovery. Hot torsion tests were utilized to validate the constitutive equations. The tests were conducted with the material of AA5083 over a range of twist rate from 0.013 to 13.70 rev/s and for each twist rate at an initial temperature range of 350°C to 550°C, respectively. The material constants determination methods are demonstrated with the proposed linear regression and the nonlinear iteration formats. A good agreement between the experimental data and the predicted results has been achieved

Physics-Based Constitutive Model to Predict Dynamic Recovery Behavior of BFe10-1-2 Cupronickel Alloy during Hot Working

2016 ◽  
Vol 35 (10) ◽  
pp. 1037-1045 ◽  
Author(s):  
Jun Cai ◽  
Xiaolu Zhang ◽  
Kuaishe Wang ◽  
Chengpeng Miao
Keyword(s):  
Constitutive Equation ◽  
Constitutive Model ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Dynamic Recovery ◽  
Hot Deformation Behavior ◽  
Absolute Relative Error ◽  
Average Absolute Relative Error ◽  
Recovery Behavior ◽  
Good Agreement

AbstractThe hot deformation behavior of BFe10-1-2 cupronickel alloy was investigated over wide ranges of deformation temperature and strain rate. The physics-based constitutive model was developed to predict the dynamic recovery (DRV) behavior of BFe10-1-2 cupronickel alloy at elevated temperatures. In order to verify the validity of the developed constitutive equation, the correlation coefficient (R) and average absolute relative error (AARE) were introduced to make statistics. The results indicated that the developed constitutive equation lead a good agreement between the calculated and experimental data and can accurately characterize the hot DRV behaviors for the BFe10-1-2 cupronickel alloy.

Deformation behavior and constitutive model for dual-phase Mg–Li alloy at elevated temperatures

2016 ◽  
Vol 26 (2) ◽  
pp. 508-518 ◽  
Author(s):  
Guo-bing WEI ◽  
Xiao-dong PENG ◽  
Fa-ping HU ◽  
Amir HADADZADEH ◽  
Yan YANG ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Dual Phase

HOT DEFORMATION BEHAVIOR OF IN SITUTIB2 REINFORCED 6351 AL COMPOSITES DURING COMPRESSION AT ELEVATED TEMPERATURES

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1432-1437
Author(s):  
SHENGLI GUO ◽  
DEFU LI ◽  
DONG CHEN ◽  
HAOWEI WANG
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Dynamic Recovery ◽  
Matrix Alloy ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Mixed Salt ◽  
Increasing Temperature

The hot deformation behavior of in situ TiB 2 reinforced 6351 Al composites synthesized by mixed salt reaction method was investigated by compression tests in the temperature range of 300-550°C and strain rate range of 0.001-10 s-1. The microstructure evolution during compression was observed by employing transmission electron microscopy (TEM). The results show that, the flow stress decreases with decreasing strain rate and increasing temperature, and the activation energy is about 169.98 kJ/mol. Microstructure observation indicates that the complex dislocation structures were formed around the TiB 2 particulate at the lower temperature and the lower strain rate and their density is reducing with increasing temperature. Dynamic recovery and recrystalized structures were observed in the lower and higher deformation temperature, respectively. At the higher strain rate, the interface separation between TiB 2 particulate and Al matrix alloy and TiB 2 particulate cracking were found in this study. The main restoration mechanisms of TiB 2/6351 composites during hot deformation are dynamic recovery and dynamic recrystallization.

Analysis of the Contact Deformation of Tread Blocks

1992 ◽  
Vol 20 (4) ◽  
pp. 230-253 ◽  
Author(s):  
T. Akasaka ◽  
K. Kabe ◽  
M. Koishi ◽  
M. Kuwashima
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Deformation Behavior ◽  
Contact Deformation ◽  
The Finite Element Method ◽  
The Road ◽  
Loss Of Contact ◽  
Tread Rubber ◽  
Good Agreement ◽  
Rubber Block

Abstract The deformation behavior of a tire in contact with the roadway is complicated, in particular, under the traction and braking conditions. A tread rubber block in contact with the road undergoes compression and shearing forces. These forces may cause the loss of contact at the edges of the block. Theoretical analysis based on the energy method is presented on the contact deformation of a tread rubber block subjected to compressive and shearing forces. Experimental work and numerical calculation by means of the finite element method are conducted to verify the predicted results. Good agreement is obtained among these analytical, numerical, and experimental results.

scholarly journals Constitutive Modeling of the Densification Behavior in Open-Porous Cellular Solids

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2731
Author(s):  
Ameya Rege
Keyword(s):  
Constitutive Model ◽  
Cell Walls ◽  
Compressive Strain ◽  
Pore Collapse ◽  
Compressive Response ◽  
Linear Elastic ◽  
Nonlinear Springs ◽  
Different Types ◽  
Point Of Intersection ◽  
Good Agreement

The macroscopic mechanical behavior of open-porous cellular materials is dictated by the geometric and material properties of their microscopic cell walls. The overall compressive response of such materials is divided into three regimes, namely, the linear elastic, plateau and densification. In this paper, a constitutive model is presented, which captures not only the linear elastic regime and the subsequent pore-collapse, but is also shown to be capable of capturing the hardening upon the densification of the network. Here, the network is considered to be made up of idealized square-shaped cells, whose cell walls undergo bending and buckling under compression. Depending on the choice of damage criterion, viz. elastic buckling or irreversible bending, the cell walls collapse. These collapsed cells are then assumed to behave as nonlinear springs, acting as a foundation to the elastic network of active open cells. To this end, the network is decomposed into an active network and a collapsed one. The compressive strain at the onset of densification is then shown to be quantified by the point of intersection of the two network stress-strain curves. A parameter sensitivity analysis is presented to demonstrate the range of different material characteristics that the model is capable of capturing. The proposed constitutive model is further validated against two different types of nanoporous materials and shows good agreement.

scholarly journals Hot Deformation Behavior and Hot Rolling Properties of a Nano-Y2O3 Addition Near-α Titanium Alloy

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 837
Author(s):  
Zhuangzhuang Zheng ◽  
Yuyong Chen ◽  
Fantao Kong ◽  
Xiaopeng Wang ◽  
Yucheng Yu
Keyword(s):  
Activation Energy ◽  
Titanium Alloy ◽  
Hot Rolling ◽  
Deformation Behavior ◽  
Processing Map ◽  
Dynamic Recovery ◽  
Alloy Sheet ◽  
Hot Deformation Behavior ◽  
Hot Processing Map ◽  
Y2o3 Addition

The hot deformation behavior and hot rolling based on the hot processing map of a nano-Y2O3 addition near-α titanium alloy were investigated. The isothermal compression tests were conducted at various deformation temperatures (950⁠–1070 °C) and strain rates (0.001–1 s−1), up to a true strain of 1.2. The flow stress was strongly dependent on deformation temperature and strain rate, decreasing with increased temperature and decreased strain rate. The average activation energy was 657.8 kJ/mol and 405.9 kJ/mol in (α + β) and β region, respectively. The high activation energy and peak stress were contributed to the Y2O3 particles and refractory elements comparing with other alloys and composites. The deformation mechanisms in the (α + β) region were dynamic recovery and spheroidization of α phase, while the β phase field was mainly controlled by the dynamic recrystallization and dynamic recovery of β grains. Moreover, the constitutive equation based on Norton–Hoff equation and hot processing map were also obtained. Through the optimal processing window determined by the hot processing map at true strains of 0.2, 0.4 and 0.6, the alloy sheet with multi-pass hot rolling (1050 °C/0.03–1 s−1) was received directly from the as-cast alloy. The ultimate tensile strength and yield strength of the alloy sheet were 1168 MPa and 1091 MPa at room temperature, and 642 MPa and 535 MPa at 650 °C, respectively, which performs some advantages in current research.

Investigation of Quench-16 Experiment With MELCOR Computer Code

2014 ◽  
Author(s):  
Petya Vryashkova ◽  
Pavlin Groudev ◽  
Antoaneta Stefanova
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Initial Temperature ◽  
Computer Code ◽  
Air Flow Rate ◽  
Fuel Rod ◽  
Fuel Bundle ◽  
Oxygen Starvation ◽  
Air Ingress ◽  
Good Agreement

This paper presents a comparison of MELCOR calculated results with experimental data for the QUENCH-16 experiment. The analysis for the air ingress experiment QUENCH-16 has been performed by INRNE. The calculations have been performed with MELCOR code. The QUENCH-16 experiment has been performed on 27-th of July 2011 in the frame of the EC-supported LACOMECO program. The experiments have focused on air ingress investigation into an overheated core following earlier partial oxidation in steam. QUENCH-16 has been performed with limited pre-oxidation and low air flow rate. One of the main objectives of QUENCH-16 was to examine the interaction between nitrogen and oxidized cladding during a prolonged period of oxygen starvation. The bundle is made from 20 heated fuel rod simulators arranged in two concentric rings and one unheated central fuel rod simulator, each about 2.5 m long. The tungsten heaters were surrounded by annular ZrO2 pellets to simulate the UO2 fuel. The geometry and most other bundle components are prototypical for Western-type PWRs. To improve the obtained results it has been made a series of calculations to select an appropriate initial temperature of the oxidation of the fuel bundle and modified correlation oxidation of Zircaloy with MELCOR computer code. The compared results have shown good agreement of calculated hydrogen and oxygen starvation in comparison with test data.

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