Welcome to Dr. L. Roy Xu's Homepage

 

Education

Research new

Teaching

Honor

xu

Publications  

Professional Activities

Research Group/Openingsnew

Movie Timenew

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Assistant Professor of Civil and Environmental Engineering, Assistant Professor of Materials Science at Vanderbilt University (August, 2001--)

 

Education


Ph.D. in Aeronautics (Minor: Material Science) California Institute of Technology Thesis: Dynamic Failure Characteristics in Layered Materials and Structures.  Advisor: Prof. Ares J. Rosakis

 

M. S. in Aircraft Design/Soild Mechanics Beijing University of Aeronautics and Astronautics, China.

 

B. S. in Aircraft (Structural) Design Beijing University of Aeronautics and Astronautics, China

 

Research


Enter here to find my current and previous research activities----including some high-speed photos and QuickTime movies. My research is focused on the mechanical response and failure of advanced materials and structures at different time-scales (static to dynamic) and length-scales (nano-scale to macro-scale). Typical applications include nano/micro-scale engineering, defense and homeland security engineering. My work is supported by the National Science Foundation, the Office of Naval Research and Oak Ridge National Laboratories

 

Teaching


Honor


Journal Publications (Including PDF Files)


 

1. L. Xu,"Exploration on Constants Independent of Materials and Layups in Transverse Matrix Cracking of Cross-ply Laminates," Advanced Composites Letter, 1993, Vol.2, No.1, pp.25-29.

 

2. L. Xu, "Interaction between Matrix Cracking and Edge Delamination in Composite Laminates, " Composites Science and Technology, 1994, Vol. 50, No.4, pp.469-478 (Full paper in PDF file).

 

3. L. Xu, C.H. Kou "Effect of Interfacial Interleaf to the Interlaminar Fracture and Intralaminar Fracture in A New Bismaleimide MatrixHistry Composites System ,"Journal of Reinforced Plastics and Composites, 1994, Vol.13, No.6, pp.509-540.

 

4. L. Xu, "Influence of Stacking Sequence on the Transverse Matrix Cracking in Continuous Fiber Crossply Laminates," Journal of Composite Materials, 1995,Vol. 29, No.10, pp.1337-1339 (Full paper in PDF file)..

 

5. L. Xu, "Study on the Characteristic Curve of Stiffness Degradation Caused by Matrix Cracking in Multi-directional Composite Laminates," Journal of Composite Materials, 1996, Vol.30, No.7, pp.820-838 (Full paper in PDF file).

 

6. L. Xu, "On the Law of the Transverse Matrix Cracking Growth in Brittle Polymeric Matrix Composite Laminates under Static Loadings," Journal of Composite Materials,1996,Vol.30, No.3, pp.384-405.

 

7. L. Xu, "Modifying Stacking Sequence Design to Delay Delamination and Matrix Crack in Laminated Composites---The Multi-Delamination-Interface Design," Journal of Reinforced Plastics and Composites , 1996 , Vol. 15, No.3, pp.230-248.

 

8. L. Xu, " Probabilistic Character of the Microcrack Growth in Brittle Layered Materials," Theoretical and Applied Fracture Mechanics, 1997, Vol.27 ,pp.167-174 (Full paper in PDF file)

 

9. L. Xu, " Some Techniques to Establish the Characteristic Curve for Microcrack Growth in Layered Materials," Engineering Fracture Mechanics, 1997, Vol. 56, No.6, pp.827-837 (Full paper in PDF file).

 

10. L. Xu, "Study on the Characteristic Stress-Life Curve of Different Materials and Failure Modes," Journal of Reinforced Plastics and Composites ,1998, Vol.16, No.17, pp.1450-1462.

 

11. L. R. Xu and A. J. Rosakis, “Impact Failure Characteristics in Sandwich Structures; Part I: Basic Failure Mode Selections,” International Journal of Solids and Structures, 2002, Vol.39, pp. 4215-35 (Full paper in PDF file)

 

12. L. R. Xu and A. J. Rosakis, “Impact Failure Characteristics in Sandwich Structures; Part II:  Effects of Impact Speed and Interfacial Strength,” International Journal of Solids and Structures, 2002, Vol.39, pp. 4237-48 (Full paper in PDF file)

 

13. L. R. Xu and A. J. Rosakis,  “An Experimental Study on Dynamic Failure Events in Homogeneous Layered Materials Using Dynamic Photoelasticity and High-speed Photography,” Optics and Laser in Engineering, Vol. 40, pp. 263-288,2003. (Full paper in PDF file)

14. L. R. Xu, Y. Y. Huang and A. J. Rosakis, “Dynamic Crack Deflection and Penetration at Interfaces in Homogeneous Materials:  Experimental Studies and Model Predictions,” Journal of the Mechanics and Physics of Solids, Vol. 51, pp.425-460, 2003. (Full paper in PDF file)

15. L. R. Xu and A. J. Rosakis, “Real-time Experimental Investigation of Dynamic Crack Branching Using High-speed Optical Diagnostics,” SEM Experimental Techniques, Vol. 27,pp.23-26, 2003. (Full paper in PDF file)

16. L. R. Xu and S. Sengupta and H. Kuai “An Experimental and Numerical Investigation on Adhesive Bonding Strengths of Polymer Materials,” International Journal of Adhesion and Adhesives, Vol. 24 , pp. 455–460, 2004 (Full paper in PDF file)

17. Zhong, W.H., Li, J., Xu, L.R ., Michel, J.A, Sullivan, L.M. and Lukehart, C.M. “Processing of Polymeric Nanocomposites Reinforced with Derivatized Graphitic Carbon Nanofibers with Linker Molecules”. Journal of Nanoscience and Nanotechnology, Vol. 4, pp.794-802, 2004.

18. L. R. Xu, V. Bhamidipati , W.-H. Zhong, J., Li, C. M. Lukehart, E. Lara-Curzio, K. C. Liu and M. J. Lance “Mechanical Property Characterization of A Polymeric Nanocomposite Reinforced by Graphitic Nanofibers with Reactive Linkers, Journal of Composite Materials, Vol. 38, pp. 1563-1582, 2004.(Full paper in PDF file)-----Top 5 in 2005; and top 10 in 2006 of the Most-Frequently-Read Articles in Journal of Composite Materials.

19. L. R. Xu , H. Kuai and S. Sengupta “ Dissimilar Material J oints with and without Free-edge Stress Singularities; Part I: A Biologically Inspired Design,” Experimental Mechanics, Vol. 44, pp. 608-615, 2004 (Full paper in PDF file)

20 . L. R. Xu , and S. Sengupta “ Dissimilar Material J oints with and without Free-edge Stress Singularities; Part II: An Integrated Numerical Analysis,” Experimental Mechanics,Vol. 44, pp. 616-621, 2004 (Full paper in PDF file)

21. Zhong, W.H., Li, J., Xu, L. R . and Lukehart, C.M. “GCNF/Epoxy Monoliths Using Reactive Oxydianiline Linker Molecules and the Effect of Nanofiber Reinforcement on Curing Conditions,” Polymer Composites, Vol. 26, pp. 128-135. 2005.

22. L. R. Xu and S. Sengupta, “Interfacial Stress Transfer and Property Mismatch in Discontinuous Nanofiber/nanotube Composite Materials,” Journal of Nanoscience and Nanotechnology, Vol. 5, pp.620-626, 2005 (Full paper in PDF file)

23 . L. R. Xu and A. J. Rosakis, “Impact Damage Visualization of Heterogeneous Two-Layer Materials Subjected to Low-speed Impact,” International Journal of Damage Mechanics, Vol. 1, pp.215-233, 2005 (Full paper in PDF file)

24 . L. R. Xu , H. Kuai and S. Sengupta“ Free-Edge Stress Singularities and Edge Modifications for Fiber Pushout Experiments,” Journal of Composite Materials, Vol. 39, pp.1103-1125, 2005. (Full paper in PDF file)

25. X.F. Li, and L. R. Xu “Transient Response of a Finite Bimaterial Plate Containing a Crack Perpendicular to and Terminating at the Interface,” ASME Journal of Applied Mechanics, 2006,Vol.73, pp.544-554 ( Full paper in PDF file)

26. P. Wang and L. R. Xu “Convex Interfacial Joints with Least Stress Singularities In Dissimilar Materials and Structures,” Mechanics of Materials, 2006, Vol.38, pp.1001-1011.( Full paper in PDF file)

27. L. R. Xu, V.Bhamidipati and S. Mahadevan “Shear-lag Analysis of Constrained Shrinkage Cracking in Reinforced Concrete Slabs,” Journal of Failure Analysis and Prevention, 2006, Vol. 6, pp. 57-66.

28. L. R. Xu and P. Wang “Dynamic Fracture Mechanics Analysis of Failure Mode Transitions along Weaken Interfaces in Elastic Solids,” Engineering Fracture Mechanics, 2006, Vol. 73, 1597-1614.( Full paper in PDF file)

29.X.F. Li, and L. R. Xu “T-stresses across Static Crack Kinking,” ASME Journal of Applied Mechanics, 2007, Vol. 74, Vol. 181-190 ( Full paper in PDF file)

30. L. R. Xu, L. Li, C. M. Lukehart and H. Kuai “Mechanical Property Characterization Nanofiber-Reinforced Composite Adhesives,” Journal of Nanoscience and Nanotechnology, in press, 2007 ( Full paper in PDF file).

 

Professional Activities


Professional Society

Proposal Referee

Journal Referee

  Personal Hobbies


Modeling Aircraft-- See F-18 Hornet aircraft model -A souvenir (I spent one month by using three simple tools ) as a player of the University Aero-model team at the Beijing University of Aeronautics and Astronautics. An exhibit at the Beijing Aerospace Museum for eight years.

 

f18-modelF18-Navy

 

  Research Group and Position Opening


My research group is growing. I plan to recruit one to two new members with good research experience in solid mechanics or material engineering. Click here for more information.

 

Research Lab


The Advanced Material Testing Laboratory includes two MTS test machines, one high-speed camera and other dynamic and static testing, material preparation and experimental mechanics facilities. More descriptions will come soon.

 

Movie Time


After extensive impact and fracture experiments of composite and layered materials using high-speed photography, I stacked all these photos for making QuickTime movies. What you will see is what the high-speed camera "saw" during the impact experiment. Enter here to watch vivid QuickTime movies. The copyright of these movies is belongs to L. R. Xu at Vanderbilt University and A. J. Rosakis at California Institute of Technology.

 

Contact Information


Dr. L. Roy Xu

Department of Civil and Environmental Engineering      

VU Station B    351831, Vanderbilt University

2301 Vanderbilt Place

 

Nashville, TN 37235, U. S. A.

 

Email: L.Roy.Xu@Vanderbilt.Edu

 

Tel: (615) 343-4891                 Fax: (615) 322-3365            

 

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