Education

• Ph.D., Ohio State University, 1991
• M.S., Ohio State University, 1985
• B.S., Arizona State University, 1982

Experience Record

• 1994-Present, Department of Mechanical Engineering, Mississippi State University, Mississippi State, MS
• 1991-1994,  Research Engineer, Babcock and Wilcox Research Center
• Dr. Daniewicz holds degrees in both Welding Engineering and Mechanical Engineering from Ohio State University. He is a member of the American Society for Testing and Materials (ASTM) E-8 Committee on Fatigue and Fracture. He received their highly prestigious Keith Miller Young Investigator Award in 1999.  He is also a member of the American Society of Mechanical Engineers (ASME), the American Welding Society (AWS), and Sigma Xi. He has authored or co-authored 22 refereed technical publications regarding fracture mechanics and fatigue.

Specialty Areas

        Fracture Mechanics and Fatigue

Research Summary

Dr. Daniewicz's research thrusts include the development of modified strip-yield models and the use of finite element analysis for prediction of fatigue crack closure and fatigue crack propagation.

Research Activities

Surface Flaw Modeling.  Surface cracks are commonly encountered in engineering practice, and current fatigue crack growth methodologies for these types of flaws neglect plasticity induced crack closure. Under some conditions such approaches may produce inaccurate and non-conservative results. Consequently, there is a strong need for a simplified closure-based crack growth prediction methodology for components exhibiting this type of flaw.  Ongoing research is focused on the development of a pragmatic modified strip-yield model for the surface flaw, allowing prediction of crack closure and fatigue crack growth along the crack front. Modified strip-yield models have found wide application for prediction of crack closure in two-dimensional cracked geometries.

Simulation of Fatigue Crack Growth in Residual Stress Fields.  It has long been recognized that the introduction of carefully controlled compressive residual stress fields is a powerful fatigue life enhancement method, and thus a key component in any service life extension program.  Advanced methodologies to model the improved resistance to fatigue crack growth associated with a prescribed residual stress distribution are being investigated.

Finite Element Modeling of Microstructurally Small Cracks.  When a crack is small, the material surrounding the crack may no longer be considered an isotropic continuum.  Each grain may be modeled as a unique plastically anisotropic material with a specific crystallographic orientation.  Single crystal plasticity theory enables the inhomogeneous nature of plastic deformation within a single grain to be simulated.  This theory forms the foundation for the development of anisotropic constitutive equations governing the plastic deformation within a grain.  When modeling the fatigue crack growth of small cracks, the interaction of the crack with grain boundaries becomes significant.  FEA analyses have been employed to simulate the interaction of a growing crack with a single grain boundary.  The boundary was approximated as a discrete material interface between two single crystals with different crystallographic orientations.

Selected Recent Publications

Solanki, K., Daniewicz, S. R., and Newman, J. C., "Finite Element Analysis of Plasticity-Induced Fatigue Crack Closure: An Overview," Engineering Fracture Mechanics, Vol. 71, 2004, pp. 149-171.

Potirniche, G. P. and Daniewicz, S. R., "Finite Element Modeling of Microstructurally Small Cracks Using Single Crystal Plasticity," International Journal of Fatigue, Vol. 25, 2003, pp. 877-884.

Solanki, K., Daniewicz, S. R., and Newman, J. C., "A New Methodology for Computing Crack Opening Values From Finite Element Analyses," accepted by Engineering Fracture Mechanics, Feb. 2003.

Potirniche, G. P. and Daniewicz, S. R., "Analysis of Crack Tip Plasticity for Microstructurally Small Cracks Using Crystal Plasticity Theory," Engineering Fracture Mechanics, Vol. 70, No. 13, 2003, pp. 1623-1643.

Solanki, K., Daniewicz, S. R., and Newman, J. C., "Finite Element Modeling of Plasticity-Induced Crack Closure with Emphasis on Geometry and Mesh Refinement Effects," Engineering Fracture Mechanics, Vol. 70, No. 12, 2003, pp. 1475-1489.

Blandford, R. S., Daniewicz, S. R., and Skinner, J. D., "Determination of the Opening Load for a Growing Fatigue Crack: Evaluation of Experimental Data Reduction Techniques and Analytical Models," Fatigue and Fracture of Engineering Materials and Structures, Vol. 25, No. 1, 2002, pp. 17-26.

Skinner, J. D. and Daniewicz, S. ., "Simulation of Plasticity-Induced Fatigue Crack Closure in Part-Through Cracked Geometries Using Finite Element Analysis, Engineering Fracture Mechanics, Vol. 69, No. 1, 2002, pp. 1-11.

Daniewicz, S. R. and Aveline, C. R., "Strip-Yield and Finite Element Analysis of Part-Through Surface Flaws," Eng. Fracture Mech., Vol. 67, No. 1, 2000, pp. 21-39.

Daniewicz, S. R., "Smoothing and Differentiating Load-Displacement Data Using a Low Pass Filter for Improved Crack Opening Load Estimates," Fatigue and Fracture of Eng. Materials and Structures, Vol. 22, 1999, pp. 273-280.

Daniewicz, S. R., "Prediction of Plasticity-Induced Closure in Surface Flaws Using a Modified Strip-Yield Model," ASTM STP 1332, 1999, pp. 453-473.

Daniewicz, S. R., "A Modified Strip-Yield Model for Prediction of Plasticity-Induced Closure in Surface Flaws," Fatigue and Fracture of Eng. Materials and Structures, Vol. 21, 1998, pp. 885-901.

Daniewicz, S. R. and Moore, D. H., "Increasing the Bending Fatigue Resistance of Spur Gear Teeth Using a Presetting Process," Int. Journal of Fatigue, Vol. 20, No. 7, 1998, pp. 537-542.

Daniewicz, S. R. and Bloom, J. M., "An Assessment of Geometry Effects on Plane Stress Fatigue Crack Closure Using a Modified Strip-Yield Model, Int. J. of Fatigue, Vol. 18, No. 7, 1996, pp. 483-490.

Daniewicz, S. R., "Accurate and Efficient Numerical Integration of Weight Functions Using Gauss-Chebyshev Quadrature," Eng. Fracture Mech., Vol. 48, No. 4, 1994, pp. 541-544.

Daniewicz, S. R., "A Closed-Form Small-Scale Yielding Collinear Strip-Yield Model for Strain Hardening Materials," Eng. Fracture Mech., Vol. 49, No. 1, 1994, pp. 95-103.

Daniewicz, S. R., Collins, J. A., and Houser, D. R., "The Stress Intensity Factor and Stiffness for a Cracked Spur Gear Tooth," J. of Mech. Design, Vol. 116, 1994, pp. 697-700.