Transcription of コースティックス法の原理と応用例 ... - jsem.jp
1 Principle ofthe M ethod ofCaustics and its Application Koji SH IM IZU (Kanto G akuin University). Fundam entalprinciple ofthe m ethod ofcaustics is described and som e applications ofthis technique on various problem s atour laboratory are show n. W hen this technique is applied to the stress- frozen m odelin photoelasticity,there appears very differentcaustic patterns from those ofusualone. Next,as an exam ple ofapplication on the dynam ic fracture problem , analysis offracture behavior ofceram ic m aterials under dynam ic loading athigh tem peratures is described. M oreover, special application ofthis principle on the m ethod ofultrasonic caustics which is used to evaluate the defect size in the circularrods in wateris show n.
2 Caustic curve 2)~3).. 1 .. 1 .. Principle ofcaustics m ethod 1 .. r w = z0 grad( s) (1). 1 . 2 . s1,2 = c0{( 1 + 2 ) ( 1 2 )}t 2 .. (2) (1) .. 2 . =0 . >0 . (initial curve) 2 . 3 . K I = (z0tc (. 0 ) 1 . 32. ) (D ). 52. 3 . 3 .. 2 . 3 . 2 K. K (a) K K (b) . K K K <0 . 3(b) .. (a) K =K >0 (b)K =K <0. Theoreticalcaustic pattern Theoreticalcaustic pattern forM ixed-m ode for M ode I ( >0, =0) condition ( >0, =0).. 4 . zi . 2m W He-Ne .. 10m m . Schem atic view ofexperim ental apparatus of caustics m ethod .. (2) .. <0 <1 . >0 >1 . >0 Caustic pattern >1 of stress-frozen m odel (PC, <0).. 5 . 5 .. K.
3 6 (PSZ) . = m . K a 7 . K . 6 . Caustic patterns underdynam ic loading Variations ofdynam ic K and crack 6. athigh tem perature (PSZ,800 ,10 FPS) length a with tim e (PSZ,800 ).. 8 .. (ultrasonic caustics) . 9 . 9 Form ation of ultrasonic . caustic pattern (Alum inum , parallelray, longitudinal wave).. 8 .. Basic conceptofultrasonic a 9 caustics .. m . 4m m .. Yu and Yu rlov:Caustics,Catastrophes and W ave Fields,Springer-Verlag, (1993),1. (1997), 129-156. :Handbook on ech.,New Jersey,Prentice-Hall,Inc.,(1987),407-476 ..Dudderar:Strain,31-2(1995),43-55. ster and .Ashbee:Ultrasonics,32-6(1994),421-424.
4 A 55-519(1989), 2348-2355. M .Suetsugu, izu and ech.,38-1(1998),1-7. (2001 8 ).
