Effect of crack on drilling vibration

Effect of drill parameters and the local crack on the dynamic characteristics of a drill during the drilling through process is investigated in this study. A pre-twisted beam with a local crack is used to simulate the cracked drill. The release energy model is employed to characterize the stiffness variation around the crack. A moving Winkler-type elastic foundation assumption is used to approximate the time dependent work piece stiffness distribution on rotating drill during the drilling process. In this article, a drill vibration model with time varied boundary condition is presented. The effects of cracks, rotational speed, pre-twisted angle and thrust force on the vibration of drill are considered. A serious vibration is observed at the moment as the drill touch the work piece in a drilling process. The simulated results also indicate that the local crack may aggravate the vibration.

[1]  A. G. Ulsoy,et al.  COMPLEX GEOMETRY, ROTARY INERTIA AND GYROSCOPIC MOMENT EFFECTS ON DRILL VIBRATIONS , 1995 .

[2]  Nikos A. Aspragathos,et al.  Identification of crack location and magnitude in a cantilever beam from the vibration modes , 1990 .

[3]  H. P. Lee.  DYNAMIC RESPONSE OF A BEAM WITH A MOVING MASS , 1996 .

[4]  B W Huang,et al.  Effect of Periodic Drilling Force on Instability in a Drilling Process , 2005 .

[5]  B.-W. Huang,et al.  Parametric resonance of a spinning pretwisted beam with time-dependent spinning rate , 1995 .

[6]  Jong-Shyong Wu,et al.  DYNAMIC ANALYSIS OF A UNIFORM CANTILEVER BEAM CARRYING A NUMBER OF ELASTICALLY MOUNTED POINT MASSES WITH DAMPERS , 2000 .

[7]  C.-L. Liao,et al.  Structural characteristics of spinning pretwisted orthotropic beams , 1992 .

[8]  M. C. Shaw.  Metal Cutting Principles , 1960 .

[9]  Etsuo Marui,et al.  Whirling Vibration in Drilling. Part 3: Vibration Analysis in Drilling Workpiece with a Pilot Hole , 1988 .

[10]  Ozan Tekinalp,et al.  Modeling and Finite Element Analysis of Drill Bit Vibrations , 1989 .

[11]  Siu-Seong Law,et al.  Study on Different Beam Models in Moving Force Identification , 2000 .

[12]  C. Liao,et al.  Parametric instability of a spinning pretwisted beam under periodic axial force , 1995 .

[13]  Chong Nam Chu,et al.  Prevention of Exit Crack in Micro Drilling of Soda-Lime Glass , 2002 .

[14]  Mustafa Sabuncu,et al.  Dynamic stability of a rotating asymmetric cross-section blade subjected to an axial periodic force , 2003 .

[15]  Chen Lien-Wen,et al.  Vibration and stability of cracked thick rotating blades , 1988 .

[16]  Mustafa Sabuncu,et al.  Buckling and dynamic stability of a rotating pretwisted asymmetric cross-section blade subjected to an axial periodic force , 2004 .

[17]  W. Ostachowicz,et al.  Transverse natural vibrations of a cracked beam loaded with a constant axial force , 1993 .

[18]  Heow Pueh Lee,et al.  Dynamic stability of a tapered cantilever beam on an elastic foundation subjected to a follower force , 1996 .

[19]  G. Beer,et al.  A graphical post-processor for computer-aided design of mine excavations , 1992 .

[20]  B. Grabowski,et al.  The Vibrational Behavior of a Turbine Rotor Containing a Transverse Crack , 1980 .

[21]  E. B. Magrab,et al.  Buckling loads and natural frequencies of drill bits and fluted cutters , 1984 .

[22]  Kittitep Fuenkajorn,et al.  Drilling-Induced Fractures in Borehole Walls , 1992 .

[23]  J. S. Rao,et al.  Vibrations of rotating, pretwisted and tapered blades , 1977 .

[24]  J. Rice,et al.  Elementary engineering fracture mechanics , 1974 .

[25]  Yitshak M. Ram,et al.  FREE VIBRATION OF A STRING WITH MOVING BOUNDARY CONDITIONS BY THE METHOD OF DISTORTED IMAGES , 1996 .

[26]  R.-F. Fung,et al.  Dynamic stability of an axially travelling STRING, /SLIDER coupling system with moving boundary , 1998 .

[27]  Ozan Tekinalp,et al.  Effects of Geometric and Process Parameters on Drill Transverse Vibrations , 1988 .

[28]  B W Huang.  Dynamic characteristics of a drill in the drilling process , 2003 .

[29]  Shu Jin-bo.  Cracking Reason Analysis on the 35CrMo Steel Drill in Forging Process , 2004 .

[30]  J. S. Rao.  Flexural Vibration of Pretwisted Tapered Cantilever Blades , 1972 .

[31]  T. Chondros,et al.  Analytical Methods in Rotor Dynamics , 1983 .