Fig. 2-31 VH/x⯲ Ⱚዊ⪛╛
Ⴖ►ᢶ Ⰾ㢎 ὂ᠒⯚ គ⮞ Ἆⲛន Ⱚዊᱣ mⰎ ᅊ㨂⯲ គἎ⑪Ṧ ⧞ᝢᰖ គἎ ᆖ គἎ⯲ ᅗᅞ⩪ ႚⶫᢲ⩎ ∞㢆㧶ᅺ ႚⲯ㧲⪆ ⲯ㫯㧶 㨎▷ ᅊᆖḖ Ⲷᆏ㧶
. ₲Ἆ⩪ ⴟᰲ⯲ Ⰾ㢎 ὂ᠒⯚ Ⴖ►ᢶ Ⰾ㢎 ὂ᠒⩪ ⋞㧲⪆ ⲯ㫯○⯚ ᩂ⩎⹚ᔲ ᅊ㨂⯲ 㪯㕶 ₩ 㔆ዊ⩪ Ḓ ▾Ⱚ☧ ∞㢆⯲ ᅗ㨿⯞ ⋺Ḓ ❶႞ᕎ⩪ 㞦⧟ 㧺
⚲ Ⱒ. ᰖ▶ → ⪊ሆ⩪▶ᜮ Ⴖ►ᢶ Ⰾ㢎 ὂ᠒Ⰾ ⧞ᝦ ⴟᰲ⯲ Ⰾ㢎 ὂ᠒⯞
Ⰾ⭃㧲⪚. ⯦⯚ ᅊ㨂⯞ 㡣ႚ㧲ዊ ⮞㨎 ❶㩲㡒⯲ ᅊ㨂⩪ ⯲㧶 ▾ Ⱚ☧⯲ ∞㢆 Ḗ Ⱚ㫮 㨿⯖ᳶ ₒ∞㧶 VH/x⯲ 㨎▷ᅊᆖḖ ᅊ㨂⯲ ⶫ➆⩪▶ Ⱚ㫮㨿(x㨿) គἎ⯖ᳶ 㣶❶㧲⪆ 㡣ႚ㧲⪚. ႛႛ ᅊ㨂⯲ ዤⰎ, 㢇, ዒⰎ⩪ Ḓ VH/x⯲ ㇶរ Ⴌᆖ ㇶ☦Ⴌ⯲ ᆚᅞḖ ╎㡎→.
Fig. 2-32(a),(b),(c)ᜮ ᅊ㨂⯲ 㢇ᆖ ዒⰎႚ 7, 10mmⰖ ᧦ ᅊ㨂⯲ ዤⰎ ⅚㫮⩪ Ḓ 㨎▷ᅊᆖ⯲ Section viewⰎ. ᅊ㨂⯲ ዤⰎႚ 1, 2, 3mmᳶ ⸷ႚ㨂⩪ ᰖ 㨎▷ᅊ ᆖ⯲ 刔Ⴌ⯚ ᅊ㨂⯲ ዤⰎ⩪ ᰖ ⸷ႚ㧲⹚Ṧ, 刕Ⴌ⯚ ὂ ᅊ㨂⩪▶ Ⱆⲯ㧲.
Fig. 2-32 VH/x⯲ ᅊ㨂⯲ ዤⰎ⩪ Ḓ 㨎▷ᅊᆖ
᪪㧶, Fig. 2-33(a),(b),(c)⯲ ᅗ⭊, ᅊ㨂⯲ ዒⰎ⫚ ዤⰎႚ 10mm, 3mmᳶ ႛႛ Ⱆⲯ 㧺 ᧦, ᅊ㨂⯲ 㢇Ⰾ 0.3, 0.5, 0.7mmᳶ ᖭ⩎⩪ ᰖ 刖, 列ႬⰎ ὂᣪ ᅊ㨂⯲ 㢇Ⰾ
⸷ႚ㨂⩪ ᰖ ⸷ႚ㧶.
Fig. 2-33 VH/x⯲ ᅊ㨂⯲ 㢇⩪ Ḓ 㨎▷ᅊᆖ
Fig. 2-34(a),(b),(c),(d),(e),(f)ᜮ ᅊ㨂⯲ 㢇ᆖ ዤⰎႚ 0.7, 3mmᳶ Ⱆⲯ㧲ᅺ, ᅊ㨂⯲
ዒⰎႚ 6mm (Fig. 2-34(a),(d)), 8mm (Fig. 2-34(b),(e)), 10mm (Fig. 2-34(c),(f))Ⱆ ᧦⯲ 㨎▷
ᅊᆖ Ⰾ ᅊ㨂⯲ ዒⰎႚ ᜲ⩎ᕂ⩪ ᰖ Fig. 2-34(a),(b),(c)⩪▶⫚ ႳⰎ VH/x⯚ x
㨿 គἎ⯲ Ⴌ⯚ ዒⰎ⩪ ╛ᆚ⩠Ⰾ Ⱆⲯ㧲⪚. 㧶㡒, Fig. 2-34(d),(e),(f)ᜮ ᅊ㨂⯲ ዒ Ⰾ㨿Ⱂ y㨿⯲ គἎ 㨎▷ ᅊᆖ⩪▶ᜮ 刘ႬⰎ ᅊ㨂⯲ ዒⰎ⩪ ⋞᳚㧲⪆ ⸷ႚ㧲⪚
.
Fig. 2-34 VH/x⯲ ᅊ㨂⯲ ዒⰎ⩪ Ḓ 㨎▷ᅊᆖ
ᅊᆖⲛ⯖ᳶ ႛ ᅊ㨂⩪▶ ▾ Ⱚ☧⯞ Ⱚ㫮 㨿⯖ᳶ ₒ∞㧶 VH/x⯲ ㇶរႬ
⯚ ᅊ㨂⯲ ዤⰎ⫚ ㇶ☦Ⴌ⯚ ᅊ㨂⯲ 㢇ᆖ ₚⲫ㧶 ᆚᅞႚ Ⱒᅺ, ⑪Ṧ ⧞ᝢᰖ ᅊ㨂⯲
ዒⰎᜮ ᅊ㨂⯲ ዒⰎ㨿⯲ VH/xႬ⯲ ∞㢆⫚ ₚⲫ㧶 ᆚᅞႚ Ⱒ.
, ,
1 L Sc
H i H i
H
total i
V V
V Max Abs Min
x x x
ª §w · § §w ··º
ww
¦
««¬ ¨© w ¸¹ ¨¨© ¨© w ¸¹¸¸¹»»¼ (18)᪪㧶 Eq. (18)ᆖ ႳⰎ ᅊ㨂⯲ ዒⰎ㨿⯖ᳶ VH/xḖ ᅊ㨂㡣ႚ ⧦ᅺṆ⸲⩪ ⯲㧶 Ⴖ⚲Ṧ㔖 㨎 ⩕⩎ ᅊᆖⰒ VH/x|total⯚ ᅊ㨂⯲ ㅎⲛᆖ ዤ⯚ ᆚᅞႚ Ⱒ. ⰎḖ Ⰾ⭃㧲⪆ Fig. 2-35⫚ Ⴓ⯚ ⲯᱣ 㡣ႚ ⧦ᅺṆ⸲⯞ ᡞ㈶㧲⪚. ✾㌮㪯 Ⱚዊ㌎Ữᰖ⩪
⯲㧶 Ⱚዊ⪛╛⯲ ᆏ႞∞㨎(S), Sᜮ ✾㌮ⰿ㋲⯲ ○⩪ ⯲ⴎ㧲Ἂ ዊ⹚(㻏䫾)⯲ Ⴌ
⯞ ႚ. ⸣, ᄚ╆Ⱚᜮ LIHaS⩪ ⯲㧲⪆ ᄚ㈶㧺 ⚲ Ⱒᜮ ᅊ㨂⯲ ㇶ☦ ዒⰎ(L)Ḗ
⧦ᅺ Ⱒ. ᪪㧶, ✾㌮ᅊᆖ, VH, VH/x, VH/y ∞㢆Ḗ ⩕⯞ ⚲ Ⱒ. 㝓㰢, VH/x,
VH/y ∞㢆ᳶ√㗊, ᅊ㨂⯲ ⮞㋲, ᅊ㨂⯲ ዒⰎ(LC), ᅊ㨂ᆖ Ⱚ㫮㨿Ⰾ Ⰾᶂᜮ ႛᡞ
(MAG) ₩ ቺ⪎⯲ 㪯㕶Ḗ ⧦ ⚲ Ⱒ. Ⲷ⧢ᢶ ⲯᱣ㡣ႚ ⧦ᅺṆ⸲⩪ ⯲㧲Ἆ, VH/x,
VH/y ∞㢆ᳶ√㗊 ㊂㧶 ᅊ㨂⯲ ዒⰎ(LC)ႚ ᄚ㈶ ႚ㧶 ㇶ☦ ᅊ㨂 ዒⰎ L
㔎 ᧦ᜮ VH/x ⯲ ㇶរႬᆖ ㇶ☦Ⴌ⯞ ႛႛ LC/SႶ Ṧ㔖 ►㕷㧲⪆ ⯦ ❷⩪ ⯲㧲
⪆ ሆ㧶 Ⴌ⯞ ⲯᱣ㡣ႚ⩪ Ⰾ⭃㧶. ⸣, 㧶㡒, LCႚ L Ⱛᄊᔲ Ⴓ⯞ ᧦⩪ᜮ LC/S Ḗ 1ᳶ 㧲⪆ ╛ዊ Eq. (18)⯲ Ⴌ⯞ ሆ㧺 ⚲ Ⱒ. ሆ㨎 Ⴌ⯚ ⯦ ❷⩪ ⯲㧲⪆ ᅊ 㨂⯲ ㅎⲛ⯞ ሆ㧲ᜮ᠊ 㫶⭃ᢶ. ⸣,
2 1
C H
C total
V C V x
§w ·
¨© w ¸¹ (19)
⪆ዊ⩪▶ C1, C2ᜮ ╛⚲ᳶ▶, ❶㩲㡒⯲ ⱆ, lift-off, Hall ᅞ⚲, Hall ⰟᲿⲞᷲ ₩
⸷㢇⋞, Ⱚ㫮ዊ⯲ 㝓○ ₩ ⰟᲿ Ⲟᷲᦋ⩪ ⯲㧲⪆ ⲯ㨎. ᰖ▶ VH/x|total⯚ ᅊ 㨂 㡣ႚ⯲ ᅊⲯⲛ ⰒⰪⰎ.[42-46]
Fig. 2-35 ⲯᱣ㡣ႚ ⧦ᅺṆ⸲
Ⲷ 3ⰿG ⹚㪯 ᅊ㨂㡣ႚ ⧦ᅺṆ⸲ ₩ 3ヂ⭪ 㣶㪞
⹚ኢዦ⹚⯲ NDT ዊ⚺⩪ ⯲㧲Ἆ, Ⱛ⩟Ⱚ⯲ ⚳᳂ᡞ ₩ Ⱛ⩟ នⰖ ㎂◲⩪ ⯲㧲
⪆ ☪╛Ⰾ Ⱒᅺ ⩠⯦Ⰾ 㞪គᢲᜮ ⪾ᷲ 㫓⯚ ⮞㩲○ᡞ ᕎⱆᢲ⩎ Ⱒ⩢. ᰖ▶, ᅊ 㨂⯞ Ⱚᡳ⯖ᳶ ᄚ㈶㧲ᅺ, ኒ ⮞㋲Ḗ 㞦⧟㧲Ἂ, 㔆ዊḖ ⲯᱣⲛ⯖ᳶ ㈮ⲯ㧺 ⚲ Ⱒᜮ
⧦ᅺṆ⸲⯞ Ⲷ❶㧶. ✾㌮㪯 Ⱚዊ㌎ỮᰖḖ 㙏㨎 㬧ᢶ Ⱚዊ⪛╛(VH)⩪ រ㧲⪆
‘Ⲷ 1Ⲣ. 1ヂ Ⱚዊ⪛╛ ㊂ ₩ ✾㠳㝒Ზ ∞▷’ ⩪▶ᜮ ㊂ᢶ 1ヂ Ⱚዊ⪛╛(VH)⯲
◖▶ ㈶Ჿ⯲ ✾㠳㝒Ზ ∞▷⯞ 㙏㧲⪆ ❺㫒⫚ ⰻ⯦⯲ ᆚᅞ⩪ រ㨎 ▾㧲ᅺ, ‘Ⲷ 2Ⲣ.
2ヂ Ⱚዊ⪛╛ ㊂ ₩ 㰢✾㘺ኒ᱂ ∞▷’ ⩪▶ᜮ 1ヂ Ⱚዊ⪛╛⩪ ⯲㨎 ⩕⩎ 2ヂ Ⱚዊ⪛╛⯞ 㰢✾㘺ኒ᱂ ∞▷⯞ 㙏㧲⪆ ◖▶ ㈶Ჿᆖ ᅊ㨂⯲ ⴎⱆ⪆√ ₩ 㔆ዊ ∞㢆
⩪ ᆚᅞ⩪ រ㨎 ᘖ⯲ 㧲⪚. ᪪㧶 ∢㧞⬮㧶 ᠊Ⰾ㗊Ḗ Ⲷᄊ 㧺 ⚲ Ⱒᜮ ⭪Ṇ⩪ រ 㨎 ዊ⚺ 㧲⪚. ‘Ⲷ 3Ⲣ. 3ヂ Ⱚዊ⪛╛ ㊂ ₩ 㡣ႚ’ ⩪▶ᜮ 3ヂ Ⱚዊ⪛╛⯚ 1ヂ
⫚ 2ヂ Ⱚዊ⪛╛⩪ រ㧲⪆ Ⲷ⧢㧶 ⧦ᅺṆ⸲⯞ ⲛ⭃㧲⪆ 㬧ᢶ. ✗ᅺ ⋺Ḏ ᄦ ᅊ㨂⯲ 㣶, ዒⰎ, 㪯╛, 㨿 ₩ ㅎⲛ⯞ 㬧 㧺⚲ Ⱒᜮ ⧦ᅺṆ⸲⯞ Ⲷ❶㧶.
Ṣ⹚ṣ⯖ᳶ ‘Ⲷ 4Ⲣ. 3ヂ⭪ ❾Ⴊ㪯 ☦㦞㝒⮂⩎’ ⩪▶ᜮ ㎎㦂㗊 ኒᰲ㧗✾ ∞⨖⩪▶
ᖪṆ ⦊Ⰾᜮ ዊ⚺Ⱂ 㗧✾ㅪ Ṿ㧫ᆖ ✾㌮㪯 Ⱚዊ㌎Ữᰖ⯲ Ⱚዊ⪛╛⯲ ᅊ㨂 ⭪Ṇ⩪
រ㧲⪆ ዊ⚺ 㧲⪚. ႞គ㰢 ▾㧶 ᕎ⭃⯞ 㘺រᳶ → ⰿ⯲ ႛ Ⲣ⩪▶ᜮ ╛⚺㧶 គ ᅞ⯲ Ⰾᳺⲛ ኖᄊ⫚ 㨂፲ Ⱚ◒㧶 ▾⯞ Ⲷ❶㧲⪚.
Fig. 3-1 ⹚㪯 ☪╛ 㡣ႚ ⧦ᅺṆ⸲
Ⲷ 1ⲢG 1ヂ Ⱚዊ⪛╛ ㊂ ₩ ✾㠳㝒Ზ ∞▷
Fig. 3-2(a)ᜮ ✾㌮㪯 Ⱚዊ㌎Ữᰖ⩪ ⯲㧲⪆ ㊂㧶 1ヂ Ⱚዊ⪛╛(VH)⯖ᳶ ◖▶
⪎ 㨿(y㨿)ᆖ 㧖㊻ⲯㅎ⫚ ◖▶⫚⯲ ╛រⲛⰒ Ⰾᡳ 㨿(x㨿)⩪▶⯲ Ⱚዊ◖▶
⯲ ㈶Ჿ⩪ ⯲㧲⪆ ሆ㨎. ⪆ዊ⩪▶ Ⱚዊ ◖▶Ḗ 㫚 ◖▶⫚ ႳⰎ ⬒√ Ⱚዊⰿ⯲
◒ዊ⩪ ►㪯ⲛ⯖ᳶ ⋞᳚㧶 Ⲟዊ ❺㫒Ḗ ㈶Ჿ㧲ᜮ ◖▶Ḗ ╆⭃㧲Ἆ, Ⱚዊ ◖▶⯲ ㈶ Ჿ⯚ Ⱚዊⰿ⯲ ◒ዊḖ ⯲ₒ㧲ᄦ ᢶ.
⪢Ḗ ⩎ 1ヂ Ⱚዊ⪛╛(Fig. 3-2(a))⯲ Ⱎ⯲⯲ マᖪ “A”ᜮ Fig. 3-2(c)⩪▶ 㣶❶㧶
₮⫚ ႳⰎ Ⱚዊ ◖▶, ⸷㢇ዊ, Ⲟ⭪ ₩ ∢㝓ⲯ ⶖ⅚ 㫲ᅗ⯲ ⪛㨿⯖ᳶ Ṩ⯚ ⰻ⯦Ⰾ 㫖ⱆᢶ. ᰖ▶, Fig. 3-2(b)⩪ ᔲ㕚ᕒ ₮⫚ ႳⰎ Ⱎ⯲⯲ ⪛⪇⩪▶ ㊂㧶 ◖▶ ㈶ Ჿ⯲ ⶖ㞦⚲ ∞▷⯞ 㙏㧲⪆, ❺㫒⫚ ⰻ⯦⯞ ሆ∞㨎⨖ 㧶.
(a) 1ヂ Ⱚዊ⪛╛ (b) Ⱎ⯲⯲ ◖▶ ㈶Ჿ⯲ ⶖ㞦⚲ ✾㠳㝒Ზ ∞▷
(c) Channel A⯲ Ⱚዊ◖▶⯲ ㈶Ჿ Fig. 3-2 1ヂ Ⱚዊ⪛╛ᆖ ✾㠳㝒Ზ ∞▷
Ⱆ₲ⲛ⯖ᳶ ᅊ㨂 ❺㫒ᜮ ᅊ㨂⯲ ⮞㋲ ₩ 㔆ዊႚ Ⱆⲯ㧲⹚ ⧤⯖⁚ᳶ Ⲛⶖ㞦⚲
រ⪇⩪▶ ᔲ㕚ᔶ. ₲Ἆ⩪ ⰻ⯦⯚ ᅺⶖ㞦 រ⪇⩪▶ ᔲ㕚ᔲ⁚ᳶ, ヂគⶖ㞦⚲, fC⩪
⯲㧶 Ⲛរ⪇ 㙏ᆖ 㧞㗊(LPF, low pass filter)⩪ ⯲㧲⪆ S/N⋞Ḗ ᘬⰖ ⚲ Ⱒ. 㧶㡒, Fig. 3-2(b)⩪▶ ヂគⶖ㞦⚲ (fC) ᘬ⯚ ⶖ㞦⚲ រ⪇ ❺㫒⯲ 㡣ቺ 㔆ዊᜮ ⰻ⯦⯲
◒ዊ(VN)ᳶ 㞪ⲯ㧶.
Fig. 3-3 Ⱎ⯲⯲ ⪛⪇⩪▶ ႛႛ⯲ ヂគ ⶖ㞦⚲⩪ Ḓ VH, VH/x
Fig. 3-3(d)ᜮ Ⱚዊ⪛╛⩪▶ ᅊ㨂⯞ ⹚ᔲᜮ 1Ⴖ ◖▶⯲ ㈶Ჿ⩪▶ 60~1kHz⯲ ヂ គ ⶖ㞦⚲(fC) Ⰾ㧲⯲ ❺㫒Ḗ ⱆሆ○㧶 ኒṖⰎ. ᪪㧶, Fig. 3-3(e)ᜮ Fig. 3-3(d)Ḗ ₒ
∞ ㄲṆ㧶 ᅊᆖḖ ᔲ㕚ᕒ. ヂគ ⶖ㞦⚲ႚ ᕈ⯞ ᅗ⭊⩪ᜮ ⰻ⯦Ⰾ ᄊ⯲ ᔲ㕚ᔲ⹚ᜮ
⧤⹚Ṧ, ᅊ㨂 ⲯ᪪㧶 ㈮㈶ᢲዊ ᅾᰚ㧲. ₲Ἆ⩪ ヂគ ⶖ㞦⚲ႚ ᘬ⯞ ᅗ⭊⩪ᜮ ⰻ⯦Ⰾ 㫖ⱆᢶ. ᰖ▶, ㇶⲛ㫮ᢶ ヂគ ⶖ㞦⚲Ḗ ⹚ⲯ㧲ᜮ ᄝⰎ ₲❶ 㧞⬮㧲.
→ ⪊ሆ⩪▶ᜮ ⚲ᡳ ❷⯖ᳶ Ⱚዊ⪛╛⯲ 㝓ⲯ ⪛⪇⩪▶ Fig. 3-2(a), (b), (c) ₩ Fig.
3-3(e)⯲ ᅊᆖḖ ⪆ ⶖἎ▶ Ⱛ⩟Ⱚႚ ヂគ ⶖ㞦⚲Ḗ ▾ⲯ㧲ᡞ᳷ ⹚ⲯ㧲⪚. Ⰾ᧦, ⰻ⯦⯲ ◒ዊ(VN)ᜮ ヂគ ⶖ㞦⚲ᳶ√㗊 Ⱚᡳ⯖ᳶ ᅞ╊ᢲἊ Ⲛⰿᢶ.
Ⲷ 2ⲢG 2ヂ Ⱚዊ⪛╛ ㊂ ₩ 㰢✾㘺ኒ᱂ ∞▷
╛ዊ 1ヂ Ⱚዊ⪛╛⩪▶ᜮ ᅊ㨂 ⲯႚ ⋞ᇪⲛ 㫯⪊㧲ᄦ 㣶㪞ᢺ ⚲ Ⱒ. ኒᲆ ᔲ, Ⱛ⩟Ⱚ⩪ ⯲㧶 㞪ⲯⰎ Ⰾᶂ⩎⹚⁚ᳶ Ⱛ⩟Ⱚ⯲ ⚳᳂ᡞ⩪ ᰖ ᅊ㨂⯲ ⴎⱆ ⪆√
ႚ 㞪⅞ ᢲᜮ ⪾ᷲ ₩ ⮞㩲○Ⰾ Ⱒ. ᰖ▶ ☦㦞㝒⮂⩎╛⩪▶ ✗ᄦ ᅊ㨂⯞
㞪⅞㧲ዊ ⮞㧶 2ヂ Ⱚዊ⪛╛⯞ ㈶Ჿ㧶. 2ヂ Ⱚዊ⪛╛(Fig. 3-4(a))⯚ ᅊ㨂❺㫒 ✾㠳 㝒Ზ⩪▶ ⩕⩎ ヂគⶖ㞦⚲(fC)Ḗ Ⰾ⭃㧲⪆ Ⲛ⪇㙏ᆖ 㧞㗊Ḗ 㙏㨎 ⰻ⯦Ⰾ ⲚႪᢶ Ⱚዊ⪛╛⯞ ⩕ᅺ, ⰎḖ Ⱚ㫮㨿(◖▶⯲ ✾㌮㨿, x㨿)⯖ᳶ ₒ∞㧲⪆ ሆ㧺 ⚲ Ⱒ
.
(a) 2ヂ Ⱚዊ⪛╛ (b) Ⱎ⯲ ⪛⪇⩪▶⯲ 㰢✾㘺ኒ᱂ ∞▷
Fig. 3-4 2ヂ Ⱚዊ⪛╛ᆖ 㰢✾㘺ኒ᱂ ∞▷
1ヂ Ⱚዊ⪛╛⩪▶ ᅊ㨂⯲ 㨿Ⰾ Ⱚ㫮㨿ᆖ ⚲⹛Ⰾᄊᔲ, ᅊ㨂⯲ ዤⰎႚ ዤᄊ ᔲ, ㅎⲛⰎ 㔆Ἆ, ᘬ⯚ ◖▶㈶Ჿ(VS)Ⰾ ᔲ㕚ᔶ. ᪪㧶, ᅊ㨂 ዒⰎႚ ዒᄊᔲ ㊻ⲯ ⪛
⪇⩪▶ ᅊ㨂Ⰾ ᖭᄦ ∞㢆ᢲ⩎ Ⱒ⯖Ἆ, 㨎ន㔆ዊ⯲ ◖▶㈶ᲿⰎ ⚲ ₶╷㧲ᄦ ᢶ.
ᰖ▶, 㬻㈯⯞ ◖▶㈶Ჿ(VS)⯖ᳶ 㧲ᅺ, ⴟ㈯⯞ 㨎ន ◖▶㈶Ჿ⯲ Ⴖ⚲(N)ᳶ 㧲ᜮ 㰢
✾㘺ኒ᱂⯞ Ⰾ⭃㧲Ἆ ᅊ㨂⯲ ⴎⱆ⪆√ ₩ 㔆ዊ⯲ ∞㢆Ḗ ㈮ⲯ㧺 ⚲ Ⱒ. ⸣, ᅊ㨂
❺㫒 㰢✾㘺ኒ᱂⩪ ⯲㧲Ἆ, Fig. 3-4(b)⯲ 刖⫚ ႳⰎ ◖▶㈶ᲿⰎ 㔊 ⪛⪇⩪▶ NⰎ 㔆 Ἆ, 㨎ន ሆⴊῖ⩪ ⮞㩲㧶 ᅊ㨂Ⰾ ṨⰎ ᕎⱆᢲ⩎ Ⱒ⯦⯞ ⯲ₒ㧲Ἂ, Fig. 3-4(b)⯲ 刕
⫚ ႳⰎ ◖▶㈶ᲿⰎ ᕈ⯚ ⪛⪇⩪▶ NⰎ 㔆Ἆ, 㨎ន ሆⴊῖ⩪ Ⱛ⯚ ᅊ㨂Ⰾ ṨⰎ ᕎ ⱆᢲ⩎ Ⱒ⯦⯞ ⯲ₒ㧶. ᪪㧶, Fig. 3-4(b)⯲ 刔⫚ ႳⰎ ◖▶㈶Ჿ Ⲟ₲⩪ ᄒㅪ NⰎ
∞㢆㧲Ἆ, 㔊 ᅊ㨂ᆖ Ⱛ⯚ ᅊ㨂Ⰾ ▸⪆ Ⱒ⩎, 㨿㭞 ⶫᅊ㨂(Multisite cracks)⯖ᳶ ₶ Ⲟ㧺 㫯᷺Ⰾ ᘬ⯦⯞ ⯲ₒ㧶. 㧶㡒, ◖▶㈶ᲿⰎ ᕈ⯚ ⪛⪇⩪▶ NⰎ 㔎 ᅗ⭊⩪ᜮ ᅊ㨂⯲ ዒⰎ㨿Ⰾ ◖▶ ✾㌮ 㨿ᆖ ⴛ⯚ ႛᡞḖ ႚ⹚ᅺ ∞㢆㧲ᅺ Ⱒ⯦⯞ ⯲ₒ㧺
⚲ Ⱒ⯖⁚ᳶ ⶖ⯲㨎⨖ 㧶.
1ヂ Ⱚዊ⪛╛⩪ᜮ ヂគⶖ㞦⚲(fC)⩪ ⯲㧲⪆ ⰻ⯦ ❺㫒Ḗ ⨗㫮❶㏊ᅺᜮ 㧲ᔲ, ᅊ㨂 ⲯṦ⯞ ㈮㈶㧲ዊ⩪ᜮ Ⱛ⩟Ⱚ⯲ ⚳᳂ᡞ⩪ Ḓ 㞪ⲯ⯲ ⪾ᷲႚ ᔲ㕚ᔺ ⚲ Ⱒ
. ᪪㧶, ✾㌮㪯 Ⱚዊ㌎Ữᰖ⯲ A/D⅚㫲ዊ ∞㨎(→ ⪊ሆ⩪▶ᜮ 8⋞㝒)⩪ ╛ន㧲 ᜮ ❺㫒ႚ 2ヂ⭪⯖ᳶ ⪎ᢲ⩎ Ⱒ⯖⁚ᳶ, ᠊Ⰾ㗊⯲ ⨫Ⰾ រ㧲. ᰖ▶, Fig. 3-5
╛ዊ ᅊ㨂❺㫒 㰢✾㘺ኒ᱂⯲ 㬻㈯⯲ ◖▶ ㈶Ჿ⯲ ㇶរႬ⯞ VM ⯖ᳶ ⹚ⲯ㧲ᅺ, ᪪ 㧶 1ヂ Ⱚዊ⪛╛⯲ ✾㠳㝒Ზ ∞▷⩪▶⯲ ⰻ⯦⯲ ◒ዊ(VN)⫚⯲ 1/4, 1/8, 1/10⩪ 㨎ន 㧲ᜮ Ⴌ⯞ ᅊ㨂 ⲯ⯲ 㧶ᅞ (VC)ᳶ ⹚ⲯ㧶.
Fig. 3-5 ᅊ㨂 ⲯ 㧶ᅞ ⹚ⲯ
Fig. 3-6 ᠊Ⰾ㗊ᱣ⯲ Ⴊ☦
→ ⪊ሆ⩪▶ᜮ Fig. 3-6⩪▶⫚ ႳⰎ 1ヂ Ⱚዊ⪛╛⩪▶ ሆ㧶 ⰻ⯦Ტ⅂, VN ⯞ Ⰾ
⭃㧲⪆ ᅊ㨂Ⰾ ⩠ᅺ 㞪គᢲᜮ ⪛⪇⩪▶ ᅊ㨂❺㫒Ḗ “0”⯖ᳶ ㄲṆ㨂⯖ᳶ⠂, ᅊ㨂 ⲯṦ⯞ 㣶㪞㧲⪚. ⸣, Ⱎ⯲ᳶ ⹚ⲯ㧲ᜮ ᅊ㨂 ⲯ⯲ 㧶ᅞ(VC) 㔊 ❺㫒㈶Ჿ (VS)⯚ ⚲ⲯ⩠Ⰾ 㣶㪞㧲ᔲ, VC Ⱛ⯚ ❺㫒㈶Ჿ⯚ “0”⯖ᳶ 㣶㪞㧲⪚⯖Ἂ, 㪞Ⲛ㰢
᠊Ⰾ㗊⯲ ⨫⯞ Ⱆ ⚲ Ⱒ. ❶ Ṫ㨎 ᅊ㨂ⲯ⯲ 㧶ᅞ VC ᜮ Ⱛ⩟Ⱚႚ ᄚ㈶㧲 ᅺⰪ 㧲ᜮ ᅊ㨂⯲ ㇶ☦ 㔆ዊḖ Ṫ㧶.
Ⲷ 3ⲢG 3ヂ Ⱚዊ⪛╛ ㊂ ₩ 㡣ႚ
3ヂ Ⱚዊ⪛╛(Fig. 3-7)⯚ 2ヂ Ⱚዊ⪛╛⩪▶ ᅊ㨂 ⲯ⯲ 㧶ᅞ(VC) 㔊 ◖▶
㈶ᲿṦ⯞ ㈶Ჿ㧲⪆ ሆ㧺 ⚲ Ⱒ. 2ヂ Ⱚዊ⪛╛⩪▶ ᅊ㨂ⲯ 㧶ᅞ VC Ḗ Ⱚᡳ⯖ᳶ
⹚ⲯ㧲ᜮ ᅗ⭊⩪ᜮ ╛ዊ ᅊ㨂❺㫒 㰢✾㘺ኒ᱂⯲ 㬻㈯⯲ ㇶរႬ(VM)ᆖ ╛ዊ 1ヂ Ⱚ ዊ⪛╛⯲ ⰻ⯦⯲ ◒ዊ(VN)⯲ 1/4, 1/8, 1/10⩪ 㨎ន㧲ᜮ Ⴌ⯞ ዊ⯖ᳶ 㧲⪚. ᪪㧶,
⚲ᡳ⯖ᳶ ⹚ⲯ㧲ᜮ ᅗ⭊⩪ᜮ ╛ዊ ᅊ㨂❺㫒 㰢✾㘺ኒ᱂ ∞▷ᅊᆖḖ 㣶❶㧲Ἆ▶, ᅊ 㨂ⲯ㧶ᅞ(VC)Ḗ Ⱛ⩟Ⱚႚ ►㕷㧺 ⚲ Ⱒᡞ᳷ 㧲⪚. ᡳ⪛╛⩪▶ᜮ VM ~ VN ⯲ 1/4, 1/8, 1/10, 1/12 Ⰾ╛⯲ ∞㢆Ḗ ₲㧲⪆ 㣶㪞㨂⯖ᳶ⠂, 㔊 ᅊ㨂Ⰾ ╷○㧲⪆ Ⲟ 㧲ᜮ ᆖⲯ ₩ ⶖ⅚⯲ Ⱛ⯚ ᅊ㨂Ⰾ ╷○㧲ᜮ ᆖⲯ⯞ 㣶㪞㧺 ⚲ Ⱒᡞ᳷ 㧲⪚.
Fig. 3-7 3ヂ Ⱚዊ⪛╛