Karl Jakus

Professor

Education:

• B.M.E., University of Wisconsin, 1963
• M.S., University of California at Berkeley, 1965
• Ph.D., University of California at Berkeley, 1968

Research Interests:

Professor Jakus’s research is in the area of mechanical behavior of brittle materials. Primary focus is on reliability and life prediction of ceramic components for structural applications. Examples of current research include strengthening ceramic components by creep induced compressive residual stresses, strengthening ceramic-fiber-reinforced-ceramic-matrix composites by high temperature load transfer from the matrix to the fibers, and generation of compressive residual stresses by non-uniform pressure assisted sintering.

Selected Publications:

• S. Widjaja, K. Jakus, R. Atri, J. E. Ritter, and S. Bhattacharya, "Residual Surface Stress by Localized Contact-Creep," J. Mater. Res., 12 [1] 210-17 (1997).
• J. E. Webb, K. Jakus, and J. E. Ritter, "High Temperature Bridging in a Vitreous Bonded Alumina," J. Am. Ceram. Soc., 80 [2] 509-12 (1997).
• S. Widjaja, K. Jakus, and J. E. Ritter, "Influence of R-Curve Behavior on Strength Degradation Due to Hertzian Indentation," J. Mat. Sci., 31, 2379-84 (1996).
• J. E. Webb, K. Jakus, and J. E. Ritter, "R-Curve and Subcritical Crack Growth Behavior at Elevated Temperatures in Coarse Grain Alumina," Acta Metallurgica et Materialia, 44 [6] 2259-64 (1996).
• K. Jakus, J. E. Ritter, R. Atri, and S. Widjaja, "Creep-Induced Strengthening of Soda-Lime Glass and Silicon Nitride," Ceram. Engr. Sci. Proc., 17 [3] 421-29 (1996).

Thesis Topics

• Sujanto Widjaja, "Creep-Induced Residual Stress Strengthening in Nicalon Fiber-Reinforced BMAS Glass Ceramic Matrix Composite," Ph.D. 1997.
• Sandeepan Bhattacharya, "Pressure Assisted Densification of Non-Homogeneous Ceramic Compacts," Ph.D. 1997.
• James E. Webb, "Elevated Temperature Effects on R-Curve Behavior in Alumina Ceramics," Ph.D. 1995.
• Revti R. Atri, "Experimental and Finite Element Study of Creep-Induced Strengthening in Glass under Three Point Bending," M.S. 1996.
• Mathew Westort, "Hot Pressing of Alumina," M.S. 1996.
• Sujanto Widjaja, "Influence of R-Curve Behavior on Strength Degradation Due to Hertzian Indentation," M.S. 1994.

Contact Information:

Office:

ELAB 322

Mail:

Karl Jakus

MIE Department

220 ELAB

University of Massachusetts

Amherst, MA 01003-2210

Phone:

(413) 545-2424

Fax:

(413) 545-1027

E-mail:

jakus@zonker.ecs.umass.edu