{"id":20230,"date":"2020-12-29T03:17:07","date_gmt":"2020-12-29T03:17:07","guid":{"rendered":"https:\/\/www.meetyoucarbide.com\/?p=20230"},"modified":"2020-12-29T03:21:43","modified_gmt":"2020-12-29T03:21:43","slug":"how-the-concept-of-fatigue-was-created-and-some-thing-have-to-know-about-it","status":"publish","type":"post","link":"https:\/\/www.meetyoucarbide.com\/ko\/how-the-concept-of-fatigue-was-created-and-some-thing-have-to-know-about-it\/","title":{"rendered":"\ud53c\ub85c\uc758 \uac1c\ub150\uc774 \uc5b4\ub5bb\uac8c \ub9cc\ub4e4\uc5b4\uc84c\uc73c\uba70 \uadf8\uac83\uc5d0 \ub300\ud574 \uc54c\uc544\uc57c \ud560 \uba87 \uac00\uc9c0 \uc0ac\ud56d"},"content":{"rendered":"
\n

\ud53c\ub85c\ud55c\uacc4\uace1\uc120(HL)\uc758 \uac1c\ub150\uc740 \ub9ac\uc5b4 \uc561\uc2ac\uc758 \ud53c\ub85c\ud55c\uacc4\uace1\uc120\uc744 \ud480 \ub54c \ucc98\uc74c \uc81c\uc548\ub418\uc5c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

1954\ub144 1\uc6d4 10\uc77c \uc774\ud0c8\ub9ac\uc544 \uc5d8\ubc14 \uc0c1\uacf5 7800m \uc0c1\uacf5\uc5d0\uc11c BOAC \ud61c\uc131\uc774 \ubd95\uad34\ud588\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

On April 8, another “comet” of BOAC crashed into the bay of Naples, Italy, killing 21 people on board. So far, all comets have been grounded.<\/strong><\/p>\n\n\n\n

\ud61c\uc131\uc758 \ube48\ubc88\ud55c \ucd94\ub77d\uc740 \uc138\uacc4\ub97c \ucda9\uaca9\uc5d0 \ube60\ub728\ub838\uc2b5\ub2c8\ub2e4. \u00a0<\/strong><\/p>\n\n\n\n

\ub2f9\uc2dc \uc708\uc2a4\ud134 \ucc98\uce60 \uc601\uad6d \ucd1d\ub9ac\ub294 \ubb34\uc2a8 \uc218\ub97c \uc368\uc11c\ub77c\ub3c4 \uc0ac\uace0 \uc6d0\uc778\uc744 \uaddc\uba85\ud558\ub77c\uace0 \uc9c0\uc2dc\ud588\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uc774\ub97c \uc704\ud574 \uc601\uad6d \ud574\uad70\uc740 \uc218\ubc31 \ubbf8\ud130 \uae4a\uc774\uc758 \ud574\uc800\uc5d0\uc11c \uc5d8\ubc14 \uc12c \uadfc\ucc98\uc5d0\uc11c \ube44\ud589\uae30 \uc794\ud574\ub97c \uc778\uc591\ud558\uae30 \uc704\ud574 \ud568\ub300\ub97c \ubcf4\ub0c8\uace0 \uc870\uc0ac\ub97c \uc704\ud574 \uc655\ub9bd \ud56d\uacf5\uae30 \uc5f0\uad6c\uc18c\uc5d0 \ubcf4\ub0c8\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uc870\uc0ac \uacb0\uacfc \ud56d\uacf5\uae30 \ucd94\ub77d\uc0ac\uace0 \ud53c\ud574\uc790\ub4e4\uc758 \ud3d0\uc5d0 \uac00\uc2a4\ud33d\ucc3d\uc73c\ub85c \uc778\ud55c \uade0\uc5f4\uc774 \ubc1c\uacac\ub3fc \ucd94\ub77d \uc804 \uae30\ub0b4 \uae30\uc555\uc774 \uae09\uaca9\ud558\uac8c \ub0ae\uc544\uc9c0\uba74\uc11c \ud3d0 \uc18d \uac00\uc2a4\uac00 \uae09\uaca9\ud788 \ud33d\ucc3d\ud574 \ud30c\uc5f4\ub41c \uac83\uc73c\ub85c \ubd84\uc11d\ub410\ub2e4. \ud3d0\uc758. \ube44\ud589\uae30 \uc794\ud574\ub97c \uc870\uc0ac\ud55c \uacb0\uacfc \uc77c\ubd80 \ud604\ucc3d\uc5d0 \uade0\uc5f4\uc774 \ub098\ud0c0\ub09c \uac83\uc73c\ub85c \ubd80\uac80 \uacb0\uacfc\uc640 \uc77c\uce58\ud588\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ub3d9\uc2dc\uc5d0 De Havilan Company\ub294 \uc0dd\uc0b0 \ubc0f \uc811\uc9c0\uc911\uc778 \ud56d\uacf5\uae30\uc5d0 \ub300\ud574 \uc5c4\uaca9\ud55c \uac80\uc0ac\ub97c \uc218\ud589\ud588\uc2b5\ub2c8\ub2e4. \ud14c\uc2a4\ud2b8\ub294 9000\uc2dc\uac04 \uc774\uc0c1 \uc9c0\uc18d\ub418\uc5c8\uace0, \ucd94\ub77d\ud55c \ud56d\uacf5\uae30 \uc794\ud574\uc758 \uade0\uc5f4\ucc98\ub7fc \ud56d\uacf5\uae30 \ud45c\uba74\uc5d0 \uade0\uc5f4\uc774 \ub098\ud0c0\ub0ac\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

According to the research and analysis of the technicians, the accident was caused by the “fatigue” of the metal materials used to make the aircraft body structure.<\/strong><\/strong><\/p>\n\n\n\n

\uad50\ub958 \uc555\ub825\uc758 \uc791\uc6a9\uc73c\ub85c \uc77c\uc815 \uc2dc\uac04\uc774 \uc9c0\ub098\uba74 \uad6d\ubd80\uc801\uc73c\ub85c \ub192\uc740 \uc751\ub825 \uc601\uc5ed\uc5d0 \ubbf8\uc138 \uade0\uc5f4\uc774 \ud615\uc131\ub418\uace0 \ubbf8\uc138 \uade0\uc5f4\uc774 \uc810\ucc28 \ud30c\ub2e8\uc73c\ub85c \ud655\uc7a5\ub429\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c\ud30c\uad34\ub294 \uac11\uc791\uc2a4\ub7fd\uace0 \uc704\uce58\uac00 \uad6d\uc18c\uc801\uc774\uba70 \ud658\uacbd\uacfc \uacb0\ud568\uc5d0 \ubbfc\uac10\ud55c \ud2b9\uc131\uc744 \uac00\uc9c0\uace0 \uc788\uc5b4 \uc801\uc2dc\uc5d0 \ubc1c\uacac\ud558\uae30\uac00 \uc27d\uc9c0 \uc54a\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

Under the impact of repeated pressurization and decompression, the skin at the square porthole of comet aircraft deforms and cracks, which eventually leads to metal fatigue fracture. As the first kind of jetliner in the world, “comet” flies faster than other jetliners, and naturally bears more pressure, which makes it easier to cause metal fatigue.<\/strong><\/strong><\/p>\n\n\n\n

Thus, through the investigation of the comet accident, a new subject – “fatigue mechanics” was born<\/strong>.<\/strong><\/strong><\/p>\n\n\n\n

\uc624\ub298 \uc6b0\ub9ac\ub294 \ud53c\ub85c \uace1\uc120\uacfc \uae30\ubcf8 \ud53c\ub85c \uae30\uacc4\uc801 \ud2b9\uc131\uc5d0 \ub300\ud574 \uc798 \uc54c\uace0 \uc774\ud574\ud558\uac8c \ub420 \uac83\uc785\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c \uace1\uc120 \ubc0f \ub300\uce6d \uc0ac\uc774\ud074 \ud53c\ub85c \uace1\uc120<\/strong><\/h2>\n\n\n\n

(1) \ud53c\ub85c\uace1\uc120\uacfc \ud53c\ub85c\ud55c\ub3c4<\/strong><\/strong><\/h3>\n\n\n\n

\ud53c\ub85c \uace1\uc120: \ud53c\ub85c \ud55c\uacc4\ub97c \uacb0\uc815\ud558\uace0 \ud53c\ub85c \uc751\ub825 \uae30\uc900\uc744 \uc124\uc815\ud558\ub294 \uae30\ucd08\uac00 \ub418\ub294 \ud53c\ub85c \uc751\ub825\uacfc \ud53c\ub85c \uc218\uba85 \uac04\uc758 \uad00\uacc4 \uace1\uc120, \uc989 SN \uace1\uc120\uc785\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

For metal materials with strain aging, such as carbon steel and ductile iron, when the cyclic stress level drops to a certain critical value, the low stress section becomes a horizontal section, which indicates that the specimen can undergo infinite stress cycles without fatigue fracture. Therefore, the corresponding stress is called fatigue limit, which is denoted as \u03c3 – 1 (symmetric cycle, r = – 1).<\/strong><\/strong><\/p>\n\n\n\n

\uc774\ub7f0 \uc885\ub958\uc758 \uc7ac\ub8cc\uac00 107\ubc88\uc758 \uc2a4\ud2b8\ub808\uc2a4 \uc0ac\uc774\ud074 \uc774\ud6c4\uc5d0\ub3c4 \ud30c\ub2e8\ub418\uc9c0 \uc54a\ub294\ub2e4\uba74 \ubb34\ud55c\ud788 \uc2a4\ud2b8\ub808\uc2a4 \uc0ac\uc774\ud074\uc744 \ubc1b\uc544\ub3c4 \ud30c\ub2e8\ub418\uc9c0 \uc54a\uc744 \uac83\uc774\ub77c\uace0 \uc0dd\uac01\ud560 \uc218 \uc788\uae30 \ub54c\ubb38\uc5d0 107\ubc88\uc758 \uc0ac\uc774\ud074\uc744 \ud53c\ub85c\ud55c\ub3c4\ub97c \uacb0\uc815\ud558\ub294 \uae30\uc900\uc73c\ub85c \uc790\uc8fc \uc0ac\uc6a9\ud55c\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ub2e4\ub978 \uc885\ub958\uc758 \uae08\uc18d \uc7ac\ub8cc\uc778 \uc54c\ub8e8\ubbf8\ub284 \ud569\uae08 \ubc0f \uc2a4\ud14c\uc778\ub9ac\uc2a4 \uc2a4\ud2f8\uc740 SN \uace1\uc120\uc5d0\uc11c \uc218\ud3c9 \ubd80\ubd84\uc774 \uc5c6\uc9c0\ub9cc \uc751\ub825\uc774 \uac10\uc18c\ud568\uc5d0 \ub530\ub77c \uc99d\uac00\ud569\ub2c8\ub2e4. \uc774\ub54c \ud2b9\uc815 \uc8fc\uae30\uc5d0\uc11c \ud30c\uad34\ub418\uc9c0 \uc54a\ub294 \uc751\ub825\uc740 \uc7ac\ub8cc\uc758 \uc11c\ube44\uc2a4 \uc694\uad6c \uc0ac\ud56d\uc5d0 \ub530\ub77c \uc870\uac74\ubd80 \ud53c\ub85c \ud55c\uacc4 \ub610\ub294 \uc720\ud55c \uc218\uba85 \ud53c\ub85c \ud55c\uacc4\ub85c\ub9cc \uc815\uc758\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

(2) \ud53c\ub85c \uace1\uc120\uc758 \uacb0\uc815<\/strong><\/strong><\/h3>\n\n\n\n

\uc77c\ubc18\uc801\uc73c\ub85c \ud53c\ub85c \uace1\uc120\uc740 \ud68c\uc804 \uad7d\ud798 \ud53c\ub85c \uc2dc\ud5d8\uc73c\ub85c \uce21\uc815\ub429\ub2c8\ub2e4. 4\uc810 \uad7d\ud798 \uc2dc\ud5d8\uae30\uc758 \uc6d0\ub9ac\ub294 \uc544\ub798 \uadf8\ub9bc\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

SN\uace1\uc120\uc758 \uace0\uc751\ub825(\uc720\ud55c\uc218\uba85) \ubd80\ubd84\uc740 \uadf8\ub8f9\uc2dc\ud5d8\ubc95\uc73c\ub85c \uce21\uc815\ud558\uc600\ub2e4. \uc911\uc559\uac12(\uc0dd\uc874\uc728 50%) \ud53c\ub85c \uc218\uba85\uc744 \uacc4\uc0b0\ud558\uae30 \uc704\ud574 \ucc98\ub9ac\ub418\uc5c8\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

The median S-N curve with a survival rate of 50% can be obtained by using the \u03c3 – 1 measured by the ascending and descending method as the lowest stress level point of the S-N curve and fitting it with the results measured by the group test method into a straight line or curve.<\/strong><\/strong><\/p>\n\n\n\n

(3) \ub2e4\uc591\ud55c \uc751\ub825 \uc0c1\ud0dc\uc5d0\uc11c\uc758 \ud53c\ub85c \ud55c\uacc4<\/strong><\/strong><\/h3>\n\n\n\n

\ub3d9\uc77c\ud55c \uc7ac\ub8cc\uc758 \ud53c\ub85c \ud55c\uacc4\ub294 \uc751\ub825 \uc0c1\ud0dc\uc5d0 \ub530\ub77c \ub2e4\ub974\uc9c0\ub9cc \uc774\ub4e4 \uc0ac\uc774\uc5d0\ub294 \uc77c\uc815\ud55c \uad00\uacc4\uac00 \uc788\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uacb0\uacfc\ub294 \ub300\uce6d \uad7d\ud798 \ud53c\ub85c \ud55c\uacc4\uc640 \ub300\uce6d \uc778\uc7a5 \uc555\ucd95 \ubc0f \ube44\ud2c0\ub9bc \ud53c\ub85c \ud55c\uacc4 \uc0ac\uc774\uc5d0 \uc77c\uc815\ud55c \uad00\uacc4\uac00 \uc788\uc74c\uc744 \ubcf4\uc5ec\uc90d\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

(4) \ud53c\ub85c\ud55c\ub3c4\uc640 \uc815\uc801\uac15\ub3c4\uc758 \uad00\uacc4<\/strong><\/strong><\/h3>\n\n\n\n

\uc2dc\ud5d8\uc740 \uae08\uc18d \uc7ac\ub8cc\uc758 \uc778\uc7a5 \uac15\ub3c4\uac00 \ud074\uc218\ub85d \ud53c\ub85c \ud55c\uacc4\uac00 \ub354 \ud06c\ub2e4\ub294 \uac83\uc744 \ubcf4\uc5ec\uc90d\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uc911\uac15\ub3c4 \ubc0f \uc800\uac15\ub3c4 \uac15\uc758 \uacbd\uc6b0 \ud53c\ub85c \ud55c\uacc4\uc640 \uc778\uc7a5 \uac15\ub3c4 \uc0ac\uc774\uc5d0 \uc120\ud615 \uad00\uacc4\uac00 \uc788\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

When \u03c3 B is low, it can be approximately written as \u03c3 – 1 = \u03c3 B.<\/strong><\/strong><\/p>\n\n\n\n

\u03c3B\uac00 \ub192\uc744\uc218\ub85d \uac70\uc758 \uc120\ud615 \uad00\uacc4\uac00 \ubc97\uc5b4\ub098\ub294\ub370, \uc774\ub294 \uac00\uc18c\uc131 \ubc0f \ud30c\uad34 \uc778\uc131\uc774 \uac10\uc18c\ud558\uace0 \uade0\uc5f4\uc774 \uc27d\uac8c \ud615\uc131\ub418\uace0 \uc804\ud30c\ub418\uae30 \ub54c\ubb38\uc785\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c\ub3c4 \ubc0f \ube44\ub300\uce6d <\/a>\uc8fc\uae30\uc801 \ud53c\ub85c \ud55c\uacc4<\/strong><\/strong><\/h2>\n\n\n\n

\ub9ce\uc740 \ubd80\ud488\uc774 \ube44\ub300\uce6d \uc21c\ud658 \ud558\uc911 \ud558\uc5d0\uc11c \uc791\ub3d9\ud558\ubbc0\ub85c \uc774\ub7ec\ud55c \ubd80\ud488\uc758 \uc124\uacc4 \ubc0f \uc7ac\ub8cc \uc120\ud0dd \uc694\uad6c\ub97c \ucda9\uc871\uc2dc\ud0a4\uae30 \uc704\ud574 \uc7ac\ub8cc\uc758 \ube44\ub300\uce6d \uc21c\ud658 \ud53c\ub85c \ud55c\uacc4\ub97c \uce21\uc815\ud558\ub294 \uac83\uc774 \ud544\uc694\ud569\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ub2e4\uc591\ud55c \ube44\ub300\uce6d \uc0ac\uc774\ud074\uc758 \ud53c\ub85c \ud55c\uacc4\ub294 \uc77c\ubc18\uc801\uc73c\ub85c \uc5d4\uc9c0\ub2c8\uc5b4\ub9c1 \ub3c4\uba74 \ubc29\ubc95\uc5d0 \uc758\ud55c \ud53c\ub85c \ub2e4\uc774\uc5b4\uadf8\ub7a8\uc5d0\uc11c \uc5bb\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ub2e4\ub978 \uadf8\ub9ac\uae30 \ubc29\ubc95\uc5d0 \ub530\ub77c \ub450 \uc885\ub958\uc758 \ud53c\ub85c \ub2e4\uc774\uc5b4\uadf8\ub7a8\uc774 \uc788\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uff081\uff09 \u03c3 a – \u03c3 m fatigue diagram<\/strong><\/h3>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Under the condition of different stress ratio R, the fatigue limit \u03c3 r expressed by \u03c3 Max is decomposed into \u03c3 A and \u03c3 m, and the fatigue diagram of \u03c3 a – \u03c3 m is obtained by making ABC curve in the coordinate system.<\/strong><\/strong><\/p>\n\n\n\n

\uff082\uff09 \u03c3 max (\u03c3 min) – \u03c3 m fatigue diagram<\/strong><\/h3>\n\n\n\n
\"\"<\/figure>\n\n\n\n

\uc11c\ub85c \ub2e4\ub978 \uc751\ub825 \ube44\uc728 R\uc5d0\uc11c \ud53c\ub85c \ud55c\uacc4\ub294 \ud53c\ub85c \ub2e4\uc774\uc5b4\uadf8\ub7a8\uc744 \ud615\uc131\ud558\uae30 \uc704\ud574 \uc88c\ud45c\uacc4\uc5d0\uc11c \uac01\uac01 \u03c3 max (\u03c3 min) \ubc0f \u03c3 m\uc73c\ub85c \ud45c\uc2dc\ub429\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

AHB\ub294 \ub2e4\ub978 R\uc5d0\uc11c \ud53c\ub85c \ud55c\uacc4 \u03c3 Max\uc785\ub2c8\ub2e4.  <\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c \ud55c\uacc4\ub294 \ud3c9\uade0 \uc751\ub825 \ub610\ub294 \uc751\ub825 \ube44\uc728\uc774 \uc99d\uac00\ud568\uc5d0 \ub530\ub77c \uc99d\uac00\ud558\uc9c0\ub9cc \uc751\ub825 \uc9c4\ud3ed a\ub294 \uac10\uc18c\ud569\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c \uacfc\ubd80\ud558 \uc800\ud56d<\/strong><\/strong><\/h2>\n\n\n\n

\uc7ac\ub8cc\uc758 \uc6d0\ub798 \ud53c\ub85c \ud55c\uacc4\ub294 \uc7ac\ub8cc\uc758 \uacfc\ubd80\ud558 \uc751\ub825 \ubc0f \ud574\ub2f9 \ub204\uc801 \uacfc\ubd80\ud558 \uc8fc\uae30\uc5d0 \ub530\ub77c \uae08\uc18d \ubd80\ud488\uc774 \ub54c\ub54c\ub85c \ub2e8\uae30 \uacfc\ubd80\ud558\ub97c \ubc1b\uc744 \ub54c \ubcc0\uacbd\ub418\uac70\ub098 \uac10\uc18c\ud558\uc9c0 \uc54a\uc744 \uc218 \uc788\uc2b5\ub2c8\ub2e4.  <\/strong><\/strong><\/p>\n\n\n\n

\uae08\uc18d\uc774 \ud53c\ub85c \ud55c\ub3c4\ubcf4\ub2e4 \ub192\uc740 \uc751\ub825 \uc218\uc900\uc5d0\uc11c \ud2b9\uc815 \uc0ac\uc774\ud074 \uc218 \ub3d9\uc548 \uc791\ub3d9\ud558\uba74 \ud53c\ub85c \ud55c\ub3c4\uc640 \ud53c\ub85c \uc218\uba85\uc774 \uac10\uc18c\ud558\uc5ec \uacfc\ubd80\ud558 \uc190\uc0c1\uc774 \ubc1c\uc0dd\ud569\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c \uacfc\ubd80\ud558 \uc190\uc0c1\uc5d0 \uc800\ud56d\ud558\ub294 \uae08\uc18d \uc7ac\ub8cc\uc758 \ub2a5\ub825\uc740 \uacfc\ubd80\ud558 \uc190\uc0c1 \uacbd\uacc4 \ub610\ub294 \uacfc\ubd80\ud558 \uc190\uc0c1 \uc601\uc5ed\uc73c\ub85c \ud45c\ud604\ub429\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uacfc\ubd80\ud558 \uc190\uc0c1 \uacbd\uacc4\ub294 \uc2e4\ud5d8\uc5d0 \uc758\ud574 \uacb0\uc815\ub429\ub2c8\ub2e4. \ud53c\ub85c \uc218\uba85\uc744 \uc904\uc774\uae30 \uc2dc\uc791\ud558\ub294 \ub2e4\uc591\ud55c \uacfc\ubd80\ud558 \uc751\ub825 \uc218\uc900\uacfc \ud574\ub2f9 \uc751\ub825 \uc8fc\uae30\ub97c \uce21\uc815\ud558\uace0 \ub2e4\uc591\ud55c \ud14c\uc2a4\ud2b8 \ud3ec\uc778\ud2b8\ub97c \uc5bb\uc2b5\ub2c8\ub2e4. \uacfc\ubd80\ud558 \uc190\uc0c1 \uacbd\uacc4\ub294 \uac01 \uc9c0\uc810\uc744 \uc5f0\uacb0\ud558\uc5ec \uad6c\ud569\ub2c8\ub2e4. \ub450 \ucffc\ub9ac\uac00 \ud638\uc758\uc801\uc774\uc9c0 \uc54a\uc74c<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c \uace1\uc120\uc758 \uace0\uc751\ub825 \uc601\uc5ed(\uc774 \uad6c\uac04\uc758 \uac01 \uc751\ub825 \uc218\uc900 \ud558\uc5d0\uc11c \ud53c\ub85c \ud30c\uad34\uc758 \uc751\ub825 \uc8fc\uae30\ub97c \uacfc\ubd80\ud558 \ub0b4\uad6c \uac12\uc774\ub77c\uace0 \ud568)\uc758 \uacfc\ubd80\ud558 \uc190\uc0c1 \uacbd\uacc4\uc640 \uc9c1\uc120 \uad6c\uac04 \uc0ac\uc774\uc758 \uadf8\ub9bc\uc790 \uc120 \uc601\uc5ed\uc744 \uacfc\ubd80\ud558 \uc190\uc0c1 \uc601\uc5ed\uc774\ub77c\uace0 \ud569\ub2c8\ub2e4. .<\/strong><\/strong><\/p>\n\n\n\n

\uc774 \uc601\uc5ed\uc5d0\uc11c \ubd80\ud488\uc774 \uacfc\ubd80\ud558\ub418\uba74 \uc7ac\ub8cc\uc758 \ud53c\ub85c \ud55c\uacc4\uac00 \ub2e4\uc591\ud55c \uc815\ub3c4\ub85c \uac10\uc18c\ud558\uace0 \ud53c\ub85c \ud55c\uacc4\uac00 \ub0b4\uad6c\uc131 \uac12 \uadfc\ucc98\uc5d0\uc11c \ub354 \ub9ce\uc774 \uac10\uc18c\ud569\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uacfc\ubd80\ud558 \uc190\uc0c1 \uacbd\uacc4(\ub610\ub294 \uacfc\ubd80\ud558 \ub0b4\uad6c \uac12)\uac00 \uac00\ud30c\ub974\uace0 \uc190\uc0c1 \uc601\uc5ed\uc774 \uc881\uc744\uc218\ub85d \ud53c\ub85c \uacfc\ubd80\ud558\uc5d0 \ub300\ud55c \uc800\ud56d\ub825\uc774 \uac15\ud569\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c \ub178\uce58 \uac10\ub3c4<\/strong><\/strong><\/h2>\n\n\n\n

\uc0ac\uc6a9\uc758 \ud544\uc694\uc131\uc73c\ub85c \uc778\ud574 \ubd80\ud488\uc5d0\ub294 \uc885\uc885 \uacc4\ub2e8, \ubaa8\uc11c\ub9ac, \ud0a4 \ud648, \uc624\uc77c \uad6c\uba4d, \ub098\uc0ac\uc0b0 \ub4f1\uc774 \uc788\uc2b5\ub2c8\ub2e4. \uc774\ub7ec\ud55c \uad6c\uc870\ub294 \uc751\ub825 \uc0c1\ud0dc\ub97c \ubcc0\uacbd\ud558\uace0 \uc751\ub825 \uc9d1\uc911\uc744 \uc720\ubc1c\ud558\ub294 \ub178\uce58 \ud6a8\uacfc\uc640 \uc720\uc0ac\ud569\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ub530\ub77c\uc11c \ub178\uce58\ub85c \uc778\ud55c \uc751\ub825\uc9d1\uc911\uc774 \ud53c\ub85c\ud55c\ub3c4\uc5d0 \ubbf8\uce58\ub294 \uc601\ud5a5\uc744 \uc774\ud574\ud558\ub294 \uac83\uc774 \uc911\uc694\ud569\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\ud53c\ub85c \ub178\uce58 \uac10\ub3c4\uc5d0 \ub530\ub77c \uc7ac\ub8cc\ub97c \ud3c9\uac00\ud560 \ub54c \ub450 \uac00\uc9c0 \uadf9\ub2e8\uc801\uc778 \uacbd\uc6b0\uac00 \uc788\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

(a) KF = KT, \uc989 Notched \uc2dc\ud3b8\uc758 \uc751\ub825 \ubd84\ud3ec\ub294 \ud0c4\uc131 \uc0c1\ud0dc\uc640 \uc815\ud655\ud788 \ub3d9\uc77c\ud558\uba70 \uc751\ub825 \uc7ac\ubd84\ud3ec\ub294 \uc5c6\ub2e4. \uc774\ub54c \ub178\uce58\ub294 \ud53c\ub85c\ud55c\ub3c4\ub97c \uac00\uc7a5 \ud06c\uac8c \uac10\uc18c\uc2dc\ud0a4\uba70, \ud53c\ub85c\ub178\uce58 \ubbfc\uac10\ub3c4 QF=1, \uc7ac\ub8cc\uc758 \ub178\uce58 \ubbfc\uac10\ub3c4\uac00 \uac00\uc7a5 \ud06c\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

(b) KF = 1, \u03c3 – 1 = \u03c3 – 1n, the notch does not reduce the fatigue limit, which indicates that the stress has a great redistribution in the fatigue process, the stress concentration effect is completely eliminated, QF = 0, the notch sensitivity of the material is the smallest.<\/strong><\/strong><\/p>\n\n\n\n

\ub530\ub77c\uc11c QF \uac12\uc740 \ud53c\ub85c \ub3d9\uc548 \uc751\ub825\uc744 \uc7ac\ubd84\ubc30\ud558\uace0 \uc751\ub825 \uc9d1\uc911\uc744 \uc904\uc774\ub294 \uc7ac\ub8cc\uc758 \ub2a5\ub825\uc744 \ubc18\uc601\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/strong><\/strong><\/p>\n\n\n\n

\uace0\uc8fc\uae30 \ud53c\ub85c: \ub300\ubd80\ubd84\uc758 \uae08\uc18d\uc740 \ub178\uce58\uc5d0 \ub9e4\uc6b0 \ubbfc\uac10\ud569\ub2c8\ub2e4. \uadc0\uac00 \ubd80\ub7ec\uc84c\ub2e4<\/strong><\/strong><\/p>\n\n\n\n

\uc800\uc8fc\uae30 \ud53c\ub85c\uc5d0\uc11c \ub300\ubd80\ubd84\uc758 \uae08\uc18d\uc740 \ub178\uce58\uc5d0 \ubbfc\uac10\ud558\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4. \ud6c4\uc790\uc758 \ub178\uce58 \ub8e8\ud2b8 \uc601\uc5ed\uc774 \uc18c\uc131 \uc601\uc5ed\uc5d0 \uc788\uc5b4 \uc751\ub825 \uc644\ud654 \ubc0f \uc751\ub825 \uc9d1\uc911 \uac10\uc18c\uac00 \ubc1c\uc0dd\ud558\uae30 \ub54c\ubb38\uc785\ub2c8\ub2e4.<\/strong><\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

The concept of fatigue limit curve (HL) was first proposed when solving the fatigue limit curve of the rear axle. On January 10, 1954, a comet of BOAC disintegrated 7800 meters above Elba, Italy. On April 8, another “comet” of BOAC crashed into the bay of Naples, Italy, killing 21 people on board. So far,…<\/p>","protected":false},"author":2,"featured_media":20231,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[79],"tags":[],"jetpack_featured_media_url":"https:\/\/www.meetyoucarbide.com\/wp-content\/uploads\/2020\/12\/\u56fe\u72471-2.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/posts\/20230"}],"collection":[{"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/comments?post=20230"}],"version-history":[{"count":0,"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/posts\/20230\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/media\/20231"}],"wp:attachment":[{"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/media?parent=20230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/categories?post=20230"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ko\/wp-json\/wp\/v2\/tags?post=20230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}