Research Activities:
My research activities focus on the integrated study of mechanical behavior and materials
science, including strength and fracture of metal matrix composites (MMCs), experimental
investigations on cyclic plastic deformation, fatigue, and associated substructures of structural
materials, multi-scale constitutive modeling, characterization and rendering of 3D realistic
complex microstructures, and optimization of microstructure and mechanical properties based on
computational mechanics. The overall goal of my research is to understand the deformation and
failure mechanisms of structural materials and develop multi-scale mechanism-based models to
predict material behavior under various loading conditions.
1. Strength and fracture mechanisms of metal matrix composites (MMCs): (1)
manufacturing of short-fiber reinforced aluminum alloy matrix composites by squeeze casting
technique; (2) strength and fractographs of aluminum matrix composites at room temperature
and elevated temperatures, (3) in situ observation of fracture process of MMCs by SEM and
TEM; (5) prediction of the mechanical properties of MMCs considering fracture mechanisms.
Fig. 1 Distribution of short fibers in -Al2O3/Al-5.5Mg composite [14]
Fig. 2 In-situ tensile process of -Al2O3/Al-5.5Mg composite [14]
Fig. 3 Tensile fracture surface of -Al2O3/Al-5.5Mg composite, indicating many heads of
broken fibers and dimples [14].
2. Cyclic plastic deformation and mechanism: (1) cyclic plastic deformation of typical
metallic materials under various cyclical loading conditions; (2) evolution of slip patterns; (3)
evolution of dislocation substructures; (4) the relationship between macroscopic mechanical
properties and microscopic substructure parameters; (5) the mechanisms of the formation of
typical dislocation substructures in metallic materials.
Fig. 4 Slip pattern of OFHC copper under 90 degree of out-of-phase [10]
Fig. 5 Dislocation substructure under fully reversed tension-compression at an axial strain
amplitude of 0.15% [6].
Equivalent Stress Magnitude (MPa)
CTM/TO
CTM/TC
CTM/NPP
CTM/ Transient Stage
CRM/TC
CTS/TC
CTS/TO
Fitting Line
200
150
100
50
0.5
1.0
1.5
2.0
2.5
-1
Reciprocal of Cell Size, 1/d, (m)
Fig. 6 Relationship between equivalent stress magnitude and reciprocal of dislocation cell size
[6]
3. Inhomogeneous plastic deformation of annealed mild steel under multiaxial stress state:
(1) Lüders band formation and propagation under multiaxial stress state; (2) inhomogeneous
cyclic plastic deformation phenomenon and the associated evolution of dislocations of mild
steels under fully reversed stress-controlled cyclic loading with the stress amplitude much lower
than the yield stress.
7 Small bonded strain gages on tubular specimen [12]
Biaxial Tension-Torsion
Axial Stress (MPa)
400
Work Hardening
Propagation of Lüders Bands
t2
300
•
t1
•
200
100
0
0.000
0.005
0.010
0.015
0.020
Extensometer Axial Strain
8 Axial stress-strain curve and formation of Luders band under biaxial tension-torsion
Shear Stress (MPa)
200
150
100
Propagation of Lüders Bands
•
Work Hardening
t1
•
50
t2
Biaxial Tension-Torsion
0
0.000
0.005
0.010
0.015
Midsection Shear Strain
9 Shear stress-strain curve under biaxial tension-torsion
0.020
0.025
0.014
Biaxial Tension-Torsion
Axial Strain
0.012
Work Hardening
Propagation of Lüders Bands
0.010
0.008
0.006
Gage 7
5
0.004
9
11 1
3
Elastic
0.002
Strain Gage
Extensometer
Avg Strain Gage
0.000
100
200
250
300
350
Time (s)
10 Variation of local axial strain with time under biaxial tension-torsion
0.016
150
Biaxial Tension-Torsion
Surface Shear Strain
Work Hardening
Propagation of Lüders Bands
0.012
0.008
Gage 6
8
4
10
0.004
2
12
Elastic
Strain Gage
Extensometer
Avg Strain Gage
0.000
100
150
200
250
300
350
Time (s)
11 Variation of local shear strain with time under biaxial tension-torsion [12]
(4) Computational mechanics: (1) constitutive model of cyclic plastic deformation; (2)
constitutive model of crystal plasticity; (3) multiaxial fatigue criterion based on the critical plane
approach
Axial Stress (MPa)
200
Experiment
Simulation
100
0
-100
OFHC Copper
Tension-compression
-200
-0.010
0.000
0.005
0.010
Axial Strain
12 Comparison of stabilized hysteresis loops of OFHC copper under tension-compression [1].
200
Experiment
-0.005
Cycles 64~128
200
Cycles 1~10
Simulation
Cycles 64, 128
Cycles 1~10
Cycle 16
Cycle 16
Cycle 32
Cycle 32
100
Axial Stress, MPa
Axial Stress, MPa
100
0
0
-100
-100
-200
-200
-100
-50
0
50
Shear Stress, MPa
100
-100
-50
0
50
Shear Stress, MPa
100
13 Comparison of stress response of OFHC copper under 90 degree out-of-phase
nonproportional loading [1].
1500
Stress, MPa
1000
500
0
-500
Simulation
Experiment
-1000
0.00
0.02
0.04
Strain
0.06
0.08
14 Fit for stress-strain curve of tested Ti-6Al-4V for the room temperature uniaxial strain history
with multiple strain rates and strain hold periods [7].
Observed Life (Cycles)
10
10
10
10
10
6
Multiaxial fatigue life of OFHC copper
with different grain size and texture
(TO: cyclic torsion; TC: Tension-compression
NPP: Nonproportional loading)
5
4
CRTM_TO
CRM_TC
CRTM_NPP
CTM_TO
CTM_TC
CTM_NPP
CTS_TO
CTS_TC
Sequence Loading
Ratchetting Loading
3
2
10
2
10
3
4
5
6
10
10
10
Predicted Life (Cycles)
15 Comparison of experimental data and predicted fatigue lives of OFHC copper [9]
(5) Rendering of 3D complex microstructures in computational modeling: (1) 3D Voronoi
tessellation; (2) efficient simulated annealing algorithms to specify the grain-size distribution,
phase distribution and texture; (3) meshing of 3D complex microstructures; (4) microstructurebased finite element analysis
16 Simulation of a dual phase microstructure:  grains and lamellate (+) grains
125 Grains
512 Grains
Target
17 Comparison of simulated and target grain orientation distributions [7].
18 Meshing of 3D non-periodic polycrystalline microstructure with C3D4 elements
19 Meshing of 3D periodic polycrystalline microstructure with C3D4 elements
20 Simulation of microstructure sampled on failure plane and the corresponding 3D FE models
(cut views on the midsection planes) [4].
21 Contours of fatigue indicator parameter (FIP) [4].
PUBLICATIONS
Journal Publications
1. Zhang, J. and Jiang, Y., “Constitutive modeling of cyclic plasticity deformation of a pure
polycrystalline copper,” International Journal of Plasticity 24, (2008), pp. 1890-1915.
J22
2. Jiang, Y. and Zhang, J., “Benchmark experiments and characteristic cyclic plasticity
deformation,” International Journal of Plasticity 24, (2008), pp. 1481-1515. J21
3. Zhao, T., Zhang, J., and Jiang, Y., “A study of fatigue crack growth of 7075-T651
aluminum alloy,” International Journal of Fatigue 30, (2008), pp. 1169-1180. J20
4. Zhang, J., Prasanna, R., Shenoy, M. M., and McDowell, D. L., “Modeling fatigue crack
nucleation at primary inclusions in carburized and shot-peened martensitic steel,”
Engineering Fracture Mechanics, 2008, doi: 10.1016/j.engfracmech.2008.10.011. J19
5. Prasanna, R., Zhang, J., and McDowell, D. L., “Subsurface fatigue crack nucleation at
primary inclusions in carburized and shot peened high strength steels: 3D finite element
modeling strategy,” Accepted by International Journal of Fatigue, 2008. J18
6. Zhang, J. and Jiang, Y., “An experimental study of the formation of typical dislocation
patterns in polycrystalline copper under cyclic shear,” Acta Materialia 55, (2007), pp.
1831-1842. J17
7. Zhang, M., Zhang, J., and McDowell, D. L., “Microstructure-based crystal-plasticity
modeling of cyclic deformation of Ti-6Al-4V,” International Journal of Plasticity 23,
(2007), pp. 1328-1348. J16
8. Shenoy, M., Zhang, J., and McDowell, D. L., “Estimating fatigue sensitivity to
polycrystalline Ni-base superalloy microstructures using a computational approach,”
Fatigue & Fracture of Engineering Materials & Structures 30, (2007), pp. 889-904. J15
9. Zhang, J. and Jiang, Y., “Fatigue of polycrystalline copper with different grain sizes and
texture,” International Journal of plasticity 22, (2006), pp. 536-556. J14
10. Zhang, J. and Jiang, Y., “An experimental investigation on cyclic plastic deformation and
substructures of polycrystalline copper,” International Journal of Plasticity 21, (2005),
pp. 2191-2211. J13
11. Zhang, J. and Jiang, Y., “An experimental study of inhomogeneous cyclic plastic
deformation of 1045 steel under multiaxial cyclic loading,” International Journal of
Plasticity 21, (2005), pp. 2174-2190. J12
12. Zhang, J. and Jiang, Y., “Luders bands propagation of 1045 steel under multiaxial stress
state,” International Journal of Plasticity 21, (2005), pp. 651-670. J11
13. Zhang, J. and Jiang, Y., “A study of inhomogeneous plastic deformation of 1045 Steel,”
ASME Journal of Engineering Materials and Technology 126, (2004), pp. 164-171. J10
14. Kang, G., Yang, C., and Zhang, J., “Tensile properties of randomly oriented short Al2O3 fiber reinforced aluminum alloy composites. I. microstructure characteristics,
fracture mechanisms and strength prediction,” Composites Part A: Applied Science and
Manufacturing, 33A, (5), (2002), pp. 647-656. J9
15. Kang, G., Yang, C., and Zhang, J., “Strengths and fracture mechanisms of Al2O3 short
fiber reinforced Al-Mg alloy matrix composite at elevated temperatures,” Journal of
Materials Science and Technology, 18, (3), (2002), pp. 257-260. J8
16. Kang, G., Gao, Q., and Zhang, J., “Tensile elastic modulus, strength and fracture of Al2O3/Al alloy composites,” Journal of Materials Science and Technology, 16, (5),
(2000), pp. 475-480. J7
17. Kang, G., Gao, Q., and Zhang, J., “Analysis and modeling of tensile behavior of Al2O3/Al alloy composites,” Engineering Mechanics (Chinese), 17, (5), (2000), pp. 4451. J6
18. Yang, C., Liu, S., Zhang, J., and Lei, T., “Tensile fracture process and interfacial strength
on -Alumina short fiber reinforced aluminum alloys,” Chinese Journal of Materials
Research, 13, (3), (1999), pp. 334-336. J5
19. Zhang, J., Yang, C., Liu, S., Zhang, X., and Kang, G., “Tensile strength and fracture
mode of -Alumina short fiber reinforced aluminum alloys,” Chinese Journal of Material
Research, 12, (3), (1998), pp. 282-286. J4
20. Yang, C., Liu, S., and Zhang, J., “Research on fracture process and strength mechanism
of Al matrix composites reinforced by two kinds of Al2O3 short fibers,” Acta Materiae
Compositae Sinica, 14, (1), (1997), pp. 27-32. J3
21. Zhang, X., Liu, S., Gao, Q., Zhang, J., and Qin, S., “TEM investigation on cracking in
Al2O3 short fiber /Al-5.5Zn composite,” Acta Materiae Compositae Sinica, 14, (2),
(1997), pp. 45-49. J2
22. Zhang, J., Yang, C., and Liu, S., “Tensile strength and fracture mechanism of short alumina fiber/aluminum alloy metal matrix composites,” Acta Materiae Compositae
Sinica, 14, (1), (1997), pp. 33-37. J1
Conference Publications
1. Jiang, Y., and Zhang, J., “Constitutive modeling of cyclic hardening, nonproportional
hardening, and stain ratcheting in cyclic plasticity,” Plasticity, 2008.
2. Jiang, Y., and Zhang, J., “Constitutive modeling of cyclic hardening and nonproportional
hardening of polycrystalline copper,” Fifth International Conference on Nonlinear
Mechanics, 2007.
3. Zhang, M., Zhang, J., McDowell, D. L., and Neu, R. W., “Investigation of complex
polycrystalline grain structures on fretting of duplex Ti-64 using 3D Voronoi
tessellation,” The 9th International Fatigue Congress 2006, Atlanta, USA.
4. Jiang, Y., and Zhang, J., 2005, “Influence of grain size and texture on cyclic plastic
deformation of polycrystalline copper,” Plasticity, 2005.
5. Jiang, Y. and Zhang, J., 2004, “Inhomogeneous cyclic plastic deformation of 1045 Steel,”
Proceedings of International Conference of Heterogeneous Materials Mechanics,
Chongqing, China, June 21-26, 2004, pp. 185-188.
6. Zhang, J. and Jiang, Y., 2004, “An investigation of nonproportional hardening of
polycrystalline copper,” Proceedings of International Conference of Heterogeneous
Materials Mechanics, Chongqing, China, June 21-26, 2004, pp. 193-196.
7. Zhang, J., and Jiang, Y., 2002, “Mechanisms of inhomogeneous cyclic plastic
deformation of 1045 steel,” 14TH US National Congress of Theoretical and Applied
Mechanics, Blacksburg, VA, June 23-28, 2002.