Quantitative evaluation of the displacement distribution and stress intensity factor of fatigue cracks healed by a controlled high-density electric current field

Fatigue cracks were healed by controlling a high-density electric current. The changes in the displacement distribution around the crack tip and the stress intensity factor before and after crack healing were evaluated quantitatively with a digital image collation method. According to the results, it was determined that the cracks were closed by approximately 2 to 7 µm in this study. On the other hand, the stress intensity factor decreased or increased depending on the conditions of the crack and the current applied. The physical restriction between the crack surfaces, such as bridging, is important with respect to lowering the stress intensity factor after healing.

[1]  Suxiang Wu,et al.  Recrystallization in fatigued copper single crystals under electropulsing , 2002 .

[2]  H. Conrad,et al.  ON THE EFFECT OF PERSISTENT SLIP BAND (PSB) PARAMETERS ON FATIGUE LIFE , 1992 .

[3]  S. Nutt,et al.  A Thermally Re-mendable Cross-Linked Polymeric Material , 2002, Science.

[4]  N. Sottos,et al.  Autonomic healing of polymer composites , 2001, Nature.

[5]  Y. Ju,et al.  Fatigue crack healing by a controlled high density electric current field , 2012 .

[6]  Hui Song,et al.  Effect of high-density electropulsing on microstructure and mechanical properties of cold-rolled TA15 titanium alloy sheet , 2009 .

[7]  Y. Ju,et al.  Healing of Fatigue Crack by High-Density Electropulsing in Austenitic Stainless Steel Treated with the Surface-Activated Pre-Coating , 2013, Materials.

[8]  T. Ogawa,et al.  Evaluating mixed-mode stress intensity factors from full-field displacement fields obtained by optical methods , 2007 .

[9]  A. K. Tieu,et al.  A study on crack healing in 1045 steel , 2006 .

[10]  Yi-zhou Zhou,et al.  Crack healing in a steel by using electropulsing technique , 2004 .

[11]  T.J.C. Liu,et al.  Thermo-electro-structural coupled analyses of crack arrest by Joule heating , 2008 .

[12]  Shaker A. Meguid,et al.  Three—dimensional dynamic finite element analysis of shot-peening induced residual stresses , 1999 .

[13]  Zhou Benlian,et al.  The effect of high current pulsing on persistent slip bands in fatigued copper single crystals , 2002 .

[14]  D. Holm,et al.  Load Interaction Effects on Compression Fatigue Crack Growth in Ductile Solids , 1988 .

[15]  C. Dong,et al.  Microstructure evolution occurring in the modified surface of 316L stainless steel under high current pulsed electron beam treatment , 2007 .

[16]  Hui Song,et al.  Microcrack healing and local recrystallization in pre-deformed sheet by high density electropulsing , 2008 .

[17]  S. Konovalov,et al.  Evolution of dislocation substructures in fatigue loaded and failed stainless steel with the intermediate electropulsing treatment , 2010 .

[18]  A. Sprecher,et al.  Effect of electric current pulses on fatigue characteristics of polycrystalline copper , 1991 .

[19]  Jie Zhang,et al.  Experimental study of electroplastic effect on stainless steel wire 304L , 2000 .

[20]  Shigemi Sato,et al.  (Crack-healing+proof test): a new methodology to guarantee the structural integrity of a ceramics component , 2002 .

[21]  D. Li,et al.  Evolution of microstructures in materials induced by electropulsing. , 2003, Micron.

[22]  Wei Zhang,et al.  Formation of a nanostructure in a low-carbon steel under high current density electropulsing , 2002 .

[23]  Zhou Benlian,et al.  The healing of quenched crack in 1045 steel under electropulsing , 2001 .