{"id":142,"date":"2016-07-23T09:03:29","date_gmt":"2016-07-23T14:03:29","guid":{"rendered":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/?page_id=142"},"modified":"2016-07-24T20:05:26","modified_gmt":"2016-07-25T01:05:26","slug":"cpfe617","status":"publish","type":"page","link":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/cpfe617\/","title":{"rendered":"Crystal Plasticity Finite Element Modeling of Fatigue and Creep-Fatigue of  Alloy 617 at High Temperature"},"content":{"rendered":"<p><!--  **************************************************Research Sponsor****************************************************- --><\/p>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Research Sponsor: <\/span><\/h4>\n<p><span style=\"color: black;font-family: Baskerville,Georgia,Arial,Garamond;font-size: small\"> U.S. Department of Energy (DoE), Nuclear Energy University Programs (NEUP) initiative. <\/span><br \/>\n<!--  ****************************************Research Goal and Objectives******************************************- --><\/p>\n<h2>Research Goal and Objectives<\/h2>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Goal:<\/span><\/h4>\n<p><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Develop novel testing and experimentally validated prediction methodologies for creep-dominated creep fatigue response of Alloy 617. <\/span><\/p>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Specific Objectives:<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> <strong>Formulate and implement models<\/strong> for the simulation of creep fatigue damage mechanisms and their interactions at the microstructure scale.<\/span><\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> <strong>Conduct microstructure simulations<\/strong> to arrive at a better understanding of creep fatigue mechanism while  developing  a microstructure-informed and experimentally validated phenomenological life prediction framework.<\/span><\/li>\n<p><!--  ********************************Overview of Computational Tasks**********************************- --><\/p>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Overview of Computational Tasks:<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Formulation and implementation of a microstructure-based creep fatigue model. <\/span>\n<ul>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Develop CPFE model for Alloy 617 for modeling creep-fatigue deformation between 850\u00b0C and 950\u00b0C. <\/span><\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Simulation-based mechanism understanding of CF interaction and life prediction through exercising the microstructure-based CF model. <\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Scheme.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-185\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Scheme-650x167.jpg\" alt=\"\" width=\"650\" height=\"167\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Scheme-650x167.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Scheme-300x77.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/ul>\n<\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Simulation-based mechanism understanding of CF interaction and life prediction through exercising the microstructure-based CF model. <\/span><!--  **************************************************Modeling Approach****************************************************- --><br \/>\n<h2>Modeling Approach<\/h2>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Crystal Plasticity Theory:<\/span><\/h4>\n<\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Crystallographic  slip driven by resolved shear stress are more favored than twin induced deformation for FCC metals. <\/span><\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Consider small elastic strain, arbitrary rotations and inelastic strains: applicable for most metals.. <\/span><\/li>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Formulation<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Multiplicative decomposition of deformation gradient to and two intermediate configurations: <\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/MultiDecom.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-196\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/MultiDecom.png\" alt=\"\" width=\"245\" height=\"16\" \/><\/a><br \/>\n<a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/SchimidKinematics.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-201\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/SchimidKinematics-650x202.jpg\" alt=\"\" width=\"650\" height=\"202\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/SchimidKinematics-650x202.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/SchimidKinematics-300x93.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Velocity gradient in different configurations:<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/TLP1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-208\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/TLP1.png\" alt=\"\" width=\"536\" height=\"65\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/TLP1.png 536w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/TLP1-300x36.png 300w\" sizes=\"auto, (max-width: 536px) 100vw, 536px\" \/><\/a><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/L1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-209\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/L1.png\" alt=\"\" width=\"519\" height=\"27\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/L1.png 519w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/L1-300x15.png 300w\" sizes=\"auto, (max-width: 519px) 100vw, 519px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\"> Decomposition of velocity  gradients in different configurations: <\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/LDecom.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-214\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/LDecom.png\" alt=\"\" width=\"475\" height=\"27\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/LDecom.png 475w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/LDecom-300x17.png 300w\" sizes=\"auto, (max-width: 475px) 100vw, 475px\" \/><\/a><\/p>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Choice of  Flow Rule and Evolution Equations:<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Solute drag creep phenomenon. <\/span>\n<ul>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Softening is observed at the tension part of first load cycle for both fatigue and creep-fatigue tests. Similar softening is also observed in the compression part after strain hold in each cycle of creep-fatigue tests. <\/span><\/li>\n<p style=\"text-align: center\"><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Softening.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-225\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Softening-650x443.jpg\" alt=\"\" width=\"416\" height=\"283\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Softening-650x443.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Softening-300x204.jpg 300w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Softening.jpg 1442w\" sizes=\"auto, (max-width: 416px) 100vw, 416px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Dislocation velocity increases with stress &#8211;&gt; dislocation drag solutes  hence extra resistance is produced &#8211;&gt;  dislocations accumulate enough energy to break solutes away from their equilibrium positions &#8211;&gt;  resistance drops as more and more solutes start moving together with  dislocations. <\/span><\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Strain hold &#8211;&gt; dislocation velocity decreases with stress &#8211;&gt; solutes settle down in new equilibrium positions &#8211;&gt; softening happens when reverse loading is applied. <\/span><\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">In a fatigue tests, solutes do not have enough time to settle down in their new equilibrium positions as reverse loading follows immediately.<\/span><\/li>\n<\/ul>\n<\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Flow rule and evolution equations to capture solute drag creep. <\/span>\n<ul>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Activation energy based flow rule for nickel-based alloy subject to cyclic loading at high temperatures (Busso[1996]): <\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FlowRule.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-235\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FlowRule.png\" alt=\"\" width=\"520\" height=\"55\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FlowRule.png 520w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FlowRule-300x31.png 300w\" sizes=\"auto, (max-width: 520px) 100vw, 520px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Slip resistance evolution (Busso[2000]): from statistically  stored forest obstacles. <\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/SlipResis.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-234\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/SlipResis.png\" alt=\"\" width=\"297\" height=\"31\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Backstress evolution (Busso[1996]): from dislocations bowing between obstacles.<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/BackStressEvo.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-233\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/BackStressEvo.png\" alt=\"\" width=\"297\" height=\"29\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">New slip resistance evolution equation proposed by incorporating an static recovery which reflects the slip resistance changes caused by solute drag creep.<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/NewSlipResis.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-232\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/NewSlipResis.png\" alt=\"\" width=\"613\" height=\"66\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/NewSlipResis.png 613w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/NewSlipResis-300x32.png 300w\" sizes=\"auto, (max-width: 613px) 100vw, 613px\" \/><\/a><\/ul>\n<\/li>\n<h2>Modeling Preparation and Calibration<\/h2>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Microstructure reconstruction and meshing<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Random initial orientation and bi-model grain size distribution from EBSD. <\/span><\/li>\n<p style=\"text-align: center\"><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/EBSDandGS.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-240\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/EBSDandGS-650x161.jpg\" alt=\"\" width=\"650\" height=\"161\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/EBSDandGS-650x161.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/EBSDandGS-300x74.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Synthetic microstructure reconstruction in DREAM.3D. <\/span><\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Surface mesh to volume mesh.<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Meshing.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-241\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Meshing-650x252.jpg\" alt=\"\" width=\"650\" height=\"252\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Meshing-650x252.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Meshing-300x116.jpg 300w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Meshing.jpg 1563w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Mesh convergence study<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Stress-strain and stress-time responses converge as grain size increases while computational costs increases. <\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/BCandConvergence.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/BCandConvergence-650x227.jpg\" alt=\"\" width=\"650\" height=\"227\" class=\"aligncenter size-large wp-image-245\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/BCandConvergence-650x227.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/BCandConvergence-300x104.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">The 140-grain RVE is chosen for all simulations. <\/span><\/li>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Model parameter calibration<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">A three stage (elastic, monotonic and hysteresis) calibration process is used to separately calibrate subsets of parameters. <\/span><\/li>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">A constrained nonlinear constrained optimization process minimizes the objective function: <\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/ObjEqn.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/ObjEqn.png\" alt=\"\" width=\"536\" height=\"86\" class=\"aligncenter size-full wp-image-247\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/ObjEqn.png 536w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/ObjEqn-300x48.png 300w\" sizes=\"auto, (max-width: 536px) 100vw, 536px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">A surrogate model based on Gaussian process to approximate the response during the second and third stages for efficiency. <\/span><\/li>\n<h2>Model Verification and Results Analysis<\/h2>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Stress-strain and stress-time response simulation. <\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Fatigue tests comparison:<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FatigueTests.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FatigueTests-650x162.jpg\" alt=\"\" width=\"650\" height=\"162\" class=\"aligncenter size-large wp-image-252\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FatigueTests-650x162.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/FatigueTests-300x75.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Creep fatigue tests comparison:<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/CreepFatigueTests1.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/CreepFatigueTests1-650x162.jpg\" alt=\"\" width=\"650\" height=\"162\" class=\"aligncenter size-large wp-image-254\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/CreepFatigueTests1-650x162.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/CreepFatigueTests1-300x74.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Analysis of CPFE Simulation Results. <\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Stress contour at different stages of the hold of the first cycle:<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_VonSameSpec.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_VonSameSpec-650x237.jpg\" alt=\"\" width=\"650\" height=\"237\" class=\"aligncenter size-large wp-image-261\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_VonSameSpec-650x237.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_VonSameSpec-300x109.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Stress distribution along a line passing the center of the RVE along X direction:<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressLineVon.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressLineVon-650x233.jpg\" alt=\"\" width=\"650\" height=\"233\" class=\"aligncenter size-large wp-image-260\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressLineVon-650x233.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressLineVon-300x107.jpg 300w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressLineVon.jpg 1858w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Histogram of von Mises stress at different stages of the first cycle:<\/span><\/li>\n<p><a href=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressHistVon.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressHistVon-650x224.jpg\" alt=\"\" width=\"650\" height=\"224\" class=\"aligncenter size-large wp-image-259\" srcset=\"https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressHistVon-650x224.jpg 650w, https:\/\/cdn-dev.vanderbilt.edu\/t2-my-dev\/wp-content\/uploads\/sites\/2159\/2016\/07\/Cycle1_StressHistVon-300x103.jpg 300w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><\/p>\n<h2>Conclusion and Future Work<\/h2>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Conclusion<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Current CPFE model takes the solute drag creep effect  into account and well predicts the first cycle responses of fatigue and creep-fatigue tests with different strain range and hold time; It also provides a qualitatively prediction of the cyclic softening.<\/span><\/li>\n<h4><span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 18px\">Future Work<\/span><\/h4>\n<li> <span style=\"font-family: Baskerville,Georgia,Arial,Garamond;font-size: 16px\">Cohesive modeling of grain boundaries is ongoing and life prediction capability is expected ultimately.<\/span><\/li>\n","protected":false},"excerpt":{"rendered":"<p>Research Sponsor: U.S. Department of Energy (DoE), Nuclear Energy University Programs (NEUP) initiative. Research Goal and Objectives Goal: Develop novel testing and experimentally validated prediction methodologies for creep-dominated creep fatigue response of Alloy 617. Specific Objectives: Formulate and implement models for the simulation of creep fatigue damage mechanisms and their interactions at the microstructure scale&#8230;.<\/p>\n","protected":false},"author":2710,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"tags":[],"class_list":["post-142","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/pages\/142","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/users\/2710"}],"replies":[{"embeddable":true,"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/comments?post=142"}],"version-history":[{"count":81,"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/pages\/142\/revisions"}],"predecessor-version":[{"id":266,"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/pages\/142\/revisions\/266"}],"wp:attachment":[{"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/media?parent=142"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/my.dev.vanderbilt.edu\/xiangzhang\/wp-json\/wp\/v2\/tags?post=142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}