172 I. 1 1955 1 2 1 195657 Shinoda et al. 1956 SKK 1956 3 1972 4 : 1 = 2 3 4 24 1 1 2004 110

熱 作 用 によるナイロンロープの 切 断 機 構 について * 高 橋 光 一 NITE NITE 2014 1955 1 1 1972 2 1990 1956 1 1975 2 Keywords : Nylon Rope Rupture, Ishioka s First Problem, Ishioka s Second Problem, Heat, Melting, Non - Newtonian Fluid 109

172 I. 1 1955 1 2 1 195657 Shinoda et al. 1956 SKK 1956 3 1972 4 : 1 = 2 3 4 24 1 1 2004 110

1956 ; 1972 2 10 2 L 1L a a 1L 1 L 1956 SKK 1956 1956 ; 1972SKK 1956 1 111

172 1. a 3 b 2 Tz T= 1 c a Tz Tz SKK 1956 SKK 1956 1. R 1R 1 mm 2. 11 mm 24 mm 4 11 mm 24 mm SKK 1956Fig. 4 3. 2 12 mm - SKK 1956Fig. 4 2 4. 8 mm 40 kg 112

SKK 1956 2 1972 20 4 2014 NITE NITE 20141955 1. 2. 3. 4. 5. 6. a 6 b 2 2. 2 SKK1956 113

172 b 0.5 m2 m 1972 1L SKK 1956 11 mm 4 C SKK 1956 Table II 3 3 Hooke 0 0 Benenson 2006 5 3 SKK1956 114

3. Benenson 2006 1 1 : 0R 4 1956 SKK 1956 NITE 3 5 NITE 1 2 IV 4 R 1972 R 0R 0 mm1r 1 mm5r 5 mm 0R 0R NITE2014 http://www.sg - mark.org/kijun/s0026-05.pdf 1972 1 5 NITE NITE 115

172 II.NITE 2014 NITE L 0 =2.8 m 50 cm h/22.5 m M 55 kg 80 kg 0R 1955 2014 NITE NITE 2014 III. a b 2 Hooke c Hooke d d1 d2 d3 d31 d32 116

MKS MKS 3.1 M=55 kg 1 Benenson Benenson et al. 2000 1 t = 0 0 = 20 20 + 2$$ + 10 m s 1 g h 0 =5 m 2 t > 0 Lt R W -1 / dr W= 1 0 S R W E Young S F s t t 4 mm 2 : d + 02$1000$10 $1$ R$10-3 v 2 = = - S 2 = - S = 0 u / + 0 S u-x, -1X 0 W 2 = 10 RW 1000$10 $1$ R$10 - W 2 u = + + + + 9.8+900~910 ms 2 S / - u 0 117

172 2 =- /- 2 0 x 2 = 0 Rx W+1 RxW x / 0 1 = ~ x + $2 1000$10 $1$ R$10 - W 2 0 2 + + x 00 m s 1 : + 0001 + 00 RW = u0 +0 = = 0 = 0 R x -0 Rx W+1 Rx WW t = 0 L = L 0, v = v 0, s = s 0 : 0 = 1- u $ =- +- 1000$10 $1$ R$10 - W 2 1 = x 0 00$10 + + 02 0 2 s 0 s 1 t L : 4 t 0 = u0 +00, 0 = 0 1 x u = +0 Rx 0 W+1 Rx W = 1-0+0 Rx = T - 2 2 Y W+1 Rx W $ +- $10 +-11$10-2 0 = T+ 2 R0 RxW+1 RxWWY x 0 2 x 2 + 00 2 + 0ms 2 6 6 10 4 N 1972 1,4002,700 kg 1.410 4 2.610 4 N 118

= 0 R-0 RxW+1 RxWW x = 2 x R -W = t0 v 0 x v 1 R1-0W 0 =- R x 0 Rx W-1 Rx W W; 0 x 0 =- R x 0 Rx x W-1 Rx x W+1W 5 0 1-0 =- R x 0 Rx x W-1 Rx x W+1W D = Rx W-R0W = 0R0 Rx x W+1 Rx x W-0W x 0.07s 7 x x = 0000 + 12 D + 2R-11$10-2 R12W+02R12W+11$10-2 W D D D + 0 D + 0 + 2R-11$10-2 +02$0+11$10-2 0 D + $0 + 00 2 W+ 0 RW F C F S + 2 n 7 119

172 = n + 2 n x W f D x = = # x # + 2 ns # 0 = 2 n 0 # 0 x 0 S 0 0 = 2 n 0 # 0 x S x 2 S = nx 2 2 0 SRx W 2 n = 0.5x = x = 0.07 nx 2 2 0 SRx W 2 + 0$0$00 2 # 2 R+0R-11$10-2 $1+02$0WW 2 2 $2$ + 1 R W Q f W f NITE Q f 1/100 Q f : DT + = f, 0< f < 1 = f = f t D c p m D S p DT + f t D 1 + f 1$10 $11$10 $1$ R$10 - W 2 $00 + f C 6 50 225 D T f 120

3.2 Hooke 1972 12 mm 75 kg0.52 m 2.5 1809.8/3.10.006 2 16 MPa Benenson et al. 2000 500 MPa 30 1 2.5 Mg M=55 kg 1 2 1 + 2 2 2.5559.8/1.4~960 N 2dr 0.004 m 3W C =F C df C r 9600.004~4 Ws 4V C S2rdS C C r S C 2 NITE 2014 r S C + $2 = 2$10 - R 2 10 W + 1$10 - R W NITE R 0S C 2 p C + 121

172 0 2$10 - + 00 RW Benenson et al.2000 500 MPa p C Q C W C = f, 0< f < 1 f 1 Q C DT + t = f t DT + f t + f 1$10 $11$10 $1$10 - D T f D T C + 220f C V C V C 440 f IV. 1 3.1 D T f 3.2 D T C 55 kg NITE2014 50 f C f 0.01 8 300 MPa 200 f C 8 NITE 1020 NITE 122

f 1/2 100 C 1/22 NITE 5 10 C 2 100 C 220 C 50 C i 1 1 0.01 ii 0 t W C t 1972 1 123

172 Benenson et al. 2000 490635 MPa 300 MPa 1 9 20 C NITE 100 C 9 124

2 H 0 m T W 2 SKK1956 T = T1+ 2 1+ Y k = ESL k Hooke H 0 T W 2 1975 10 mm 80 kg 5 m 0R 350 kgw 0 m 160 kg 2 kh/wl1 T~3W=240 kg 1990 2 : 0 m 1 0 m 350 kgw ihooke Newton iihooke Newton i 1992 NITE 2014 tan d 125

172 NITE 201440 C 20 C 0.02< tan d <0.07 ii 2 1 2 V. k R 126

1 1 2 43 25 2014 7 NITE 1955 20 1 2 2014 1 2 127

172 2001 100 2001: 2003 2014 ; 2007 NITE 2014 NITE 128

2014NITE http://www.geocities.jp/shigeoishioka/new32.html. 1972 139 2007 1956 2007. 1990 5 pp 123-153. 1992 NITE 2014 http://www.geocities.jp/shigeoishioka/new39.html. last retrieved in July 30, 2015. 2003 3 H 2001 5 Benenson W, Harris J W, Stocker H and Lutz H ed.2000handbook of physics Springer. Shinoda G, Kajiwara N and Kawabe H 1956Dynamical behaviour of a nylon climbing rope Technology Reports of the Osaka University, 6 43. Abstract The mechanism of nylon - rope rupture under the circumstances that give rise to stress in the rope is considered by taking the experiment conducted by NITE 2014into account. The climbing accident happened in the northern Japan Alps in January 1955 raised the issue of whether nylon rope is cut by the natural rock edge has been considered to be solved. In the endeavour to resolve the problem, Ishioka addressed two problems concerning the anomalous phenomena in rupture events, which are called Ishioka s first and second problems in this note.these problems seem neither to have been solely reconsidered in successive works so far nor to have been systematically reviewed.in this note, an idea that sheds a light on these two Ishioka s problems is proposed. Dynamical and thermal influences are considered which lead to the rope - rupture.the dynamically generated stresses are tension and pressure.their thermal influence emerges as the action to nylon fibres of heats that are generated between the rope and the edge of a plate prepared to cut the nylon rope in the NITE experiment.we aim at quantifying how much dynamical stress is converted to heat. The tension of the rope combined with the gravity is the most important factor that determines the falling motion of the weight at the end of the rope.elastic approximation to the tension will be employed in order to simplify the arguments.frictional force between the rope and the surface of the cutting plate together with the diffusion of heat within the rope are small and are neglected. First, we consider the heat generated at the edge of the cutting plate just after the weight ceases free fall. Second, the pressure to the nylon rope from the edge and the rupture stress is compared. Third, the conversion of the work done by the above pressure to heat is evaluated and is compared with the known thermal property of nylon. It is shown that the third factor mentioned above is significant and that Ishioka s first problem will be solved by taking account of this effect. Finally, it is noted that Ishioka s second problem can be closely associated to the property of the non - Newtonian fluid. 129