| 1 | |
| 00:00:04,980 --> 00:00:07,380 | |
| بسم الله الرحمن الرحيم السلام عليكم ورحمة الله | |
| 2 | |
| 00:00:07,380 --> 00:00:12,080 | |
| وبركاته هنكمل في مادة تصميم الألات المحاضرات | |
| 3 | |
| 00:00:12,080 --> 00:00:17,320 | |
| الفاتة كنا نحكي عن ال design for dynamic loading | |
| 4 | |
| 00:00:17,320 --> 00:00:23,540 | |
| حكينا عن ال fluctuating stress diagramاليوم هنكمل | |
| 5 | |
| 00:00:23,540 --> 00:00:27,720 | |
| هنحكي عن ال fatigue failure criteria زي ما انتوا | |
| 6 | |
| 00:00:27,720 --> 00:00:32,460 | |
| شايفين الشكل هذا بوريجينا اكتر من fatigue ال | |
| 7 | |
| 00:00:32,460 --> 00:00:40,500 | |
| criteria في عند ال SY او في صدربرج، عند ال Godman، | |
| 8 | |
| 00:00:40,500 --> 00:00:46,900 | |
| عند ال Morrow، عند ال SWT، عند ال Gerber، عند | |
| 9 | |
| 00:00:46,900 --> 00:00:51,690 | |
| الأزمة اللي بتكلمش عليهم واحدة واحدةهذه كلها او | |
| 10 | |
| 00:00:51,690 --> 00:00:57,230 | |
| نحكي فتيك design criteria كل واحدة له مياز وكل | |
| 11 | |
| 00:00:57,230 --> 00:01:02,070 | |
| واحدة لها عيوبأول واحدة اللى هى ال Godman احنا | |
| 12 | |
| 00:01:02,070 --> 00:01:05,870 | |
| حاكينا عن ال Godman بس هنعيد يعنيين اول شىء linear | |
| 13 | |
| 00:01:05,870 --> 00:01:13,270 | |
| العلاقة جاية بين ال SUT و ال SE كل كرفاته طبعا ل | |
| 14 | |
| 00:01:13,270 --> 00:01:18,550 | |
| infinite life ل infinite life ال Godman simple | |
| 15 | |
| 00:01:18,550 --> 00:01:22,150 | |
| conservative يعني بتعمل prediction لل fatigue | |
| 16 | |
| 00:01:22,150 --> 00:01:27,670 | |
| failure قبل ما حقيقة أن يصير failure و كويسة لل | |
| 17 | |
| 00:01:27,670 --> 00:01:32,360 | |
| design purposes لأنها simple و بسيطةزي ما احكيه | |
| 18 | |
| 00:01:32,360 --> 00:01:35,080 | |
| not typical of the data، يعني ال experimental data | |
| 19 | |
| 00:01:35,080 --> 00:01:41,500 | |
| مش متطابقه مع ال .. ال mathematical model بتاع | |
| 20 | |
| 00:01:41,500 --> 00:01:42,100 | |
| Godman | |
| 21 | |
| 00:01:45,720 --> 00:01:48,860 | |
| applicable for positive mean stress إذا بدنا نروح | |
| 22 | |
| 00:01:48,860 --> 00:01:52,540 | |
| على ال negative mean stress بيصير عنده ال design | |
| 23 | |
| 00:01:52,540 --> 00:01:58,040 | |
| criteria linear عند ال SE أو خط أفقي عند ال SE ال | |
| 24 | |
| 00:01:58,040 --> 00:02:02,100 | |
| failure line اللي هو sigma A على SE زي sigma M على | |
| 25 | |
| 00:02:02,100 --> 00:02:05,300 | |
| ST بيستوى واحد if we include factor of safety | |
| 26 | |
| 00:02:05,300 --> 00:02:09,970 | |
| بيصيرSigma A على SE زي Sigma M على SUT بيستوى واحد | |
| 27 | |
| 00:02:09,970 --> 00:02:15,330 | |
| على N ومنها بنحسب N بيستوى Sigma A على SE زي Sigma | |
| 28 | |
| 00:02:15,330 --> 00:02:18,110 | |
| M على SUT أوصى ناقص وانت تلاحظوا هنا في ال | |
| 29 | |
| 00:02:18,110 --> 00:02:24,810 | |
| criteria عندي ال alternating مع endurance المين | |
| 30 | |
| 00:02:24,810 --> 00:02:32,370 | |
| معه tensile المورو | |
| 31 | |
| 00:02:32,370 --> 00:02:34,230 | |
| اللي هي هذه المورو | |
| 32 | |
| 00:02:40,990 --> 00:02:48,830 | |
| ال morally linear زيها زي ال good man بس اللي | |
| 33 | |
| 00:02:48,830 --> 00:02:54,150 | |
| باختلاف بدل ما تم استبدال ال SUT ب sigma F bar او | |
| 34 | |
| 00:02:54,150 --> 00:03:01,470 | |
| sigma F prime sigma F bar اللي هي ال true fracture | |
| 35 | |
| 00:03:01,470 --> 00:03:05,590 | |
| strength sigma F prime اللي هي ال fatigue strength | |
| 36 | |
| 00:03:05,590 --> 00:03:06,190 | |
| coefficient | |
| 37 | |
| 00:03:10,770 --> 00:03:15,330 | |
| ال moral line هو ال moral provides a reasonable | |
| 38 | |
| 00:03:15,330 --> 00:03:18,170 | |
| fit to the fatigue data on both positive and | |
| 39 | |
| 00:03:18,170 --> 00:03:23,270 | |
| negative mean stress site يعني اي نحظة ال .. ال | |
| 40 | |
| 00:03:23,270 --> 00:03:28,330 | |
| experimental data جاي كان زي هيك فاحنا روحنا | |
| 41 | |
| 00:03:28,330 --> 00:03:34,150 | |
| باتجاه to fit ال experimental data اكتر من اياش ال | |
| 42 | |
| 00:03:34,150 --> 00:03:34,550 | |
| good one | |
| 43 | |
| 00:03:43,240 --> 00:03:47,940 | |
| it tends to be slightly toward the conservative | |
| 44 | |
| 00:03:47,940 --> 00:03:51,900 | |
| side for positive mean stress يعني بتكون تعطينا | |
| 45 | |
| 00:03:51,900 --> 00:03:55,240 | |
| conservative results في حال كان ال mean stress | |
| 46 | |
| 00:03:55,240 --> 00:04:00,720 | |
| موجب and slightly to the non conservative side for | |
| 47 | |
| 00:04:00,720 --> 00:04:04,140 | |
| negative mean stress إذا كان ال stress negative | |
| 48 | |
| 00:04:04,140 --> 00:04:08,900 | |
| بتكون مش conservativeطبعا هي زي ما حكينا linear و | |
| 49 | |
| 00:04:08,900 --> 00:04:13,980 | |
| simple زي ال godman لكن بتعطينا بيتار fit لل | |
| 50 | |
| 00:04:13,980 --> 00:04:19,060 | |
| experimental data يعني من عيوبها انها limited يعني | |
| 51 | |
| 00:04:19,060 --> 00:04:23,100 | |
| مش دايما تكون متاحة عند ال sigma f bar او sigma f | |
| 52 | |
| 00:04:23,100 --> 00:04:23,460 | |
| prime | |
| 53 | |
| 00:04:28,870 --> 00:04:32,970 | |
| عشان هيك فينا ال sigma f prime معادلة مرة تلانا | |
| 54 | |
| 00:04:32,970 --> 00:04:38,310 | |
| سابقا في حالة ال English units sigma f prime | |
| 55 | |
| 00:04:38,310 --> 00:04:42,270 | |
| بيستوي ال C2 زائد خمسين او في حالة ال metric unit | |
| 56 | |
| 00:04:42,270 --> 00:04:45,510 | |
| sigma f bar او sigma f prime بيستوي ال C2 زائد | |
| 57 | |
| 00:04:45,510 --> 00:04:50,700 | |
| تلاتمية و خمس و اربعين الفتيك في ال criteriaاللحظة | |
| 58 | |
| 00:04:50,700 --> 00:04:56,040 | |
| هنا عندي هنا sigma a على se و هنا sigma m على | |
| 59 | |
| 00:04:56,040 --> 00:05:00,080 | |
| sigma f prime يعني انا استبدلت ايش ال SUT ب sigma | |
| 60 | |
| 00:05:00,080 --> 00:05:05,980 | |
| f prime او sigma f bar او sigma f prime ال factor | |
| 61 | |
| 00:05:05,980 --> 00:05:09,280 | |
| of safety هيكون sigma a على se زي sigma m على | |
| 62 | |
| 00:05:09,280 --> 00:05:15,100 | |
| sigma f prime bar او او الانف بيستوى sigma a على | |
| 63 | |
| 00:05:15,100 --> 00:05:17,660 | |
| se زي sigma m على sigma f prime او | |
| 64 | |
| 00:05:22,650 --> 00:05:27,190 | |
| ال gear bar جاية | |
| 65 | |
| 00:05:27,190 --> 00:05:33,890 | |
| بين ال sut و ال se لكن مش linear يعني هي زي ال | |
| 66 | |
| 00:05:33,890 --> 00:05:38,150 | |
| goodman بس ال goodman جاية linear هذه non linear | |
| 67 | |
| 00:05:38,150 --> 00:05:43,610 | |
| معناته it fits جاية باتجاه ال experimental data it | |
| 68 | |
| 00:05:43,610 --> 00:05:46,470 | |
| fits ال experimental data أحسن من goodman | |
| 69 | |
| 00:05:49,990 --> 00:05:53,930 | |
| slightly non-conservative especially for stress | |
| 70 | |
| 00:05:53,930 --> 00:05:59,630 | |
| conditions near the ordinate يعني بتكون أعلى شوية | |
| 71 | |
| 00:05:59,630 --> 00:06:03,250 | |
| من ال experimental data و بالذات في المنطقة هذه | |
| 72 | |
| 00:06:03,250 --> 00:06:07,070 | |
| applies | |
| 73 | |
| 00:06:07,070 --> 00:06:12,250 | |
| to positive mean stress to conservative if applied | |
| 74 | |
| 00:06:12,250 --> 00:06:15,910 | |
| to negative means ممكن انا اعمل extrapolation لل | |
| 75 | |
| 00:06:15,910 --> 00:06:17,030 | |
| curve اتجاه | |
| 76 | |
| 00:06:20,010 --> 00:06:24,550 | |
| الـ negative برضه بتعطينا إيش إذا بتحاولوا تعملوا | |
| 77 | |
| 00:06:24,550 --> 00:06:31,630 | |
| plot لها هتكون لاحظوا ال curve جاي مش شكل هذا | |
| 78 | |
| 00:06:31,630 --> 00:06:39,540 | |
| تقريبا حسين زي هيكهكون تحت ال experimentally تحت | |
| 79 | |
| 00:06:39,540 --> 00:06:43,420 | |
| ال experimental data الفيرق criteria المعادلة اللي | |
| 80 | |
| 00:06:43,420 --> 00:06:48,240 | |
| هي sigma a على se زي sigma m على sut لكل تربيع | |
| 81 | |
| 00:06:48,240 --> 00:06:51,800 | |
| بيساوي واحد و ال factor of safety بيساوي واحد على | |
| 82 | |
| 00:06:51,800 --> 00:06:55,860 | |
| اتنين في sut على sigma m لكل تربيع في sigma a على | |
| 83 | |
| 00:06:55,860 --> 00:07:00,400 | |
| se في minus واحد زي جزر تربيع لواحد زي اتنين sigma | |
| 84 | |
| 00:07:00,400 --> 00:07:04,820 | |
| m se على sut sigma a لكل تربيع هذا في حالة كان ال | |
| 85 | |
| 00:07:04,820 --> 00:07:05,780 | |
| stress positive | |
| 86 | |
| 00:07:12,050 --> 00:07:20,110 | |
| ال Soderbergh جاي بين ال S Y و ال S E جاي بين ال S | |
| 87 | |
| 00:07:20,110 --> 00:07:24,450 | |
| Y و ال S E ultra conservative يعني conservative | |
| 88 | |
| 00:07:24,450 --> 00:07:28,790 | |
| بالزيادة يعني عندنا ال .. ال .. ال .. ال good man | |
| 89 | |
| 00:07:28,790 --> 00:07:32,650 | |
| conservative و هد جاي لورا هتكون conservative أكتر | |
| 90 | |
| 00:07:33,920 --> 00:07:39,000 | |
| مزيتها انها بتعمل check for both ال fatigue | |
| 91 | |
| 00:07:39,000 --> 00:07:43,460 | |
| failure و ال yield لان جاي بتعمل check for both | |
| 92 | |
| 00:07:43,460 --> 00:07:46,400 | |
| اللي هو fatigue failure و ال yield | |
| 93 | |
| 00:07:49,320 --> 00:07:53,820 | |
| العلاقة linear ال filler line اللي هو اللي هو جاي | |
| 94 | |
| 00:07:53,820 --> 00:07:57,800 | |
| بين ال S Y و ال S E بيسوا S A على S E زاد Sigma M | |
| 95 | |
| 00:07:57,800 --> 00:08:01,780 | |
| على S Y بيسوا واحد factor of safety بيكون Sigma A | |
| 96 | |
| 00:08:01,780 --> 00:08:05,160 | |
| على S E زاد Sigma M على S Y او ناقص واحد for | |
| 97 | |
| 00:08:05,160 --> 00:08:10,000 | |
| positive mean stress ال | |
| 98 | |
| 00:08:10,000 --> 00:08:14,560 | |
| asthma elliptic جاي | |
| 99 | |
| 00:08:14,560 --> 00:08:23,560 | |
| بين ال S Y و ال S E لكن هيشnon-linear فهي checks | |
| 100 | |
| 00:08:23,560 --> 00:08:28,220 | |
| for both yield failure و fatigue failure it's | |
| 101 | |
| 00:08:28,220 --> 00:08:34,420 | |
| better fit ال experimental data ال line اللي هو | |
| 102 | |
| 00:08:34,420 --> 00:08:37,940 | |
| sigma a على s e لكل تربيع زي sigma m على s y | |
| 103 | |
| 00:08:37,940 --> 00:08:42,400 | |
| بالساوية واحد هذه التربيع على فكرة | |
| 104 | |
| 00:08:55,210 --> 00:08:59,490 | |
| فهذا هتكون sigma A على SE لكل تربيع زي sigma M على | |
| 105 | |
| 00:08:59,490 --> 00:09:01,890 | |
| أسوأ لكل تربيع بيساوي واحد و ال factor of safety | |
| 106 | |
| 00:09:01,890 --> 00:09:06,110 | |
| بيساوي sigma A على SE لكل تربيع زي sigma M على | |
| 107 | |
| 00:09:06,110 --> 00:09:09,310 | |
| أسوأ لكل تربيع كله أس ناقص نص هذا for positive | |
| 108 | |
| 00:09:09,310 --> 00:09:17,410 | |
| pain stress هذا | |
| 109 | |
| 00:09:17,410 --> 00:09:22,270 | |
| ال Smith Watson Tuber SWT Smith Watson Tuber | |
| 110 | |
| 00:09:26,760 --> 00:09:32,080 | |
| طبعا في ال .. ال .. Soderbergh .. في ال .. | |
| 111 | |
| 00:09:32,080 --> 00:09:37,680 | |
| Soderbergh .. في ال .. في الأزمة الليبتك .. في ال | |
| 112 | |
| 00:09:37,680 --> 00:09:44,890 | |
| Godman .. في ال Gerber .. في ال Moroهذا كان تعمل | |
| 113 | |
| 00:09:44,890 --> 00:09:49,190 | |
| fit لل experimental data تعمل fit ل .. للبيانات | |
| 114 | |
| 00:09:49,190 --> 00:09:54,390 | |
| just a fit بدون ماخوض فيه تفاصيل بدون ماخوض تفاصيل | |
| 115 | |
| 00:09:54,390 --> 00:10:00,230 | |
| نظرية لكن ال morrow او ال ال SWT اللي هى Smith | |
| 116 | |
| 00:10:00,230 --> 00:10:01,230 | |
| Watson Tupper | |
| 117 | |
| 00:10:04,110 --> 00:10:07,310 | |
| الليبتيك it has a theoretical basis rather than | |
| 118 | |
| 00:10:07,310 --> 00:10:09,810 | |
| simply attempting to fit the data يعني إلها أساس | |
| 119 | |
| 00:10:09,810 --> 00:10:14,410 | |
| نظري ليس فقط أن تم ال fit that is printed لكن إلها | |
| 120 | |
| 00:10:14,410 --> 00:10:18,150 | |
| أساس نظري it is primarily associated with the | |
| 121 | |
| 00:10:18,150 --> 00:10:22,110 | |
| strain life method يعني ..يعني ..يعني إلها أساس | |
| 122 | |
| 00:10:22,110 --> 00:10:26,630 | |
| مرتبط بطريقة ال strain life method لكن في حالة ال | |
| 123 | |
| 00:10:26,630 --> 00:10:30,590 | |
| high cycle fatigue يعني بين العشرة بين الألف cycle | |
| 124 | |
| 00:10:30,590 --> 00:10:32,690 | |
| لمليون cycle | |
| 125 | |
| 00:10:35,040 --> 00:10:37,820 | |
| بيكون ال plastic strain صغير الفئة الكرتيرية | |
| 126 | |
| 00:10:37,820 --> 00:10:43,340 | |
| بتاعتها اللي هي SE بيساوي الجزر التربيعي ل sigma | |
| 127 | |
| 00:10:43,340 --> 00:10:46,860 | |
| max sigma alternating او ما هي sigma max اش بيساوي | |
| 128 | |
| 00:10:46,860 --> 00:10:50,140 | |
| sigma mean زي sigma alternating الجزر التربيعي ل | |
| 129 | |
| 00:10:50,140 --> 00:10:52,500 | |
| sigma mean زي sigma alternating في sigma | |
| 130 | |
| 00:10:52,500 --> 00:10:57,940 | |
| alternating وال factor of safety بيساوي SE على | |
| 131 | |
| 00:10:57,940 --> 00:10:58,820 | |
| الجزر التربيعي | |
| 132 | |
| 00:11:01,560 --> 00:11:07,940 | |
| سيجما ام زي سيجما اي في سيجما اي | |
| 133 | |
| 00:11:07,940 --> 00:11:12,040 | |
| دي | |
| 134 | |
| 00:11:12,040 --> 00:11:15,080 | |
| is a criterion اللي هي المعادلة ان بينا ان انا | |
| 135 | |
| 00:11:15,080 --> 00:11:21,020 | |
| عندي سيجما ام وسيجما alternating بس this criterion | |
| 136 | |
| 00:11:21,020 --> 00:11:23,960 | |
| is not a function of ultimate strength مش هي لا | |
| 137 | |
| 00:11:23,960 --> 00:11:26,660 | |
| تعتبر .. مش function في ال ultimate strength or | |
| 138 | |
| 00:11:26,660 --> 00:11:33,840 | |
| any other static strength او أسوايso its curve | |
| 139 | |
| 00:11:33,840 --> 00:11:38,640 | |
| does not intersect the mean stress line يعني عندي | |
| 140 | |
| 00:11:38,640 --> 00:11:44,840 | |
| هين مش مبين عند ال SUT بس و بتالي المعادلة بتتقطش | |
| 141 | |
| 00:11:44,840 --> 00:11:46,780 | |
| و بتتقطش مع المحور الأفضل | |
| 142 | |
| 00:11:51,940 --> 00:11:55,320 | |
| it's strange for positive mean stress should be | |
| 143 | |
| 00:11:55,320 --> 00:11:57,720 | |
| limited by the yield line لأن في yield line دي | |
| 144 | |
| 00:11:57,720 --> 00:12:02,540 | |
| بيكون واصل هي ال yield line بين أسواي و أسواي يعني | |
| 145 | |
| 00:12:02,540 --> 00:12:09,780 | |
| بتكون هي valid لحد هنا لحد | |
| 146 | |
| 00:12:09,780 --> 00:12:15,960 | |
| يعني يعني في البنطقة هذه مش لازم تخطى ال yield | |
| 147 | |
| 00:12:15,960 --> 00:12:16,220 | |
| line | |
| 148 | |
| 00:12:19,310 --> 00:12:23,670 | |
| it is usually also accepted for negative mean | |
| 149 | |
| 00:12:23,670 --> 00:12:27,190 | |
| stress ينفع استخدامها في حالة ال mean stress يكون | |
| 150 | |
| 00:12:27,190 --> 00:12:27,770 | |
| negative | |
| 151 | |
| 00:12:33,480 --> 00:12:36,840 | |
| كان الملاحظة الأخيرة هذه تنطبق عليهم كلهم تقريبا | |
| 152 | |
| 00:12:36,840 --> 00:12:40,140 | |
| بس commonly used for predicting an equivalent | |
| 153 | |
| 00:12:40,140 --> 00:12:44,420 | |
| completely reverse stress for a fluctuating state | |
| 154 | |
| 00:12:44,420 --> 00:12:47,280 | |
| of stress that does not predict infinite life يعني | |
| 155 | |
| 00:12:47,280 --> 00:12:52,040 | |
| في حال طلع ال factor of shift أقل من واحد احنا | |
| 156 | |
| 00:12:52,040 --> 00:12:57,720 | |
| بنجيب equivalent reversed stress عادة بستخدمها هذه | |
| 157 | |
| 00:12:57,720 --> 00:13:00,360 | |
| النظرية اللي هي S W T | |
| 158 | |
| 00:13:04,260 --> 00:13:21,820 | |
| طيب .. هنشوف مثال عندي | |
| 159 | |
| 00:13:21,820 --> 00:13:27,150 | |
| واحد و نص انش Diameter barhas been machined from | |
| 160 | |
| 00:13:27,150 --> 00:13:37,110 | |
| an AISI 1050 called drone bar فعندي قطع ميكانيكية | |
| 161 | |
| 00:13:37,110 --> 00:13:41,530 | |
| قطرها واحد | |
| 162 | |
| 00:13:41,530 --> 00:13:47,730 | |
| و نص انش machined | |
| 163 | |
| 00:13:53,940 --> 00:13:59,060 | |
| من ال material اللي هي ألف | |
| 164 | |
| 00:13:59,060 --> 00:14:07,920 | |
| و خمسين كولدرون | |
| 165 | |
| 00:14:07,920 --> 00:14:12,640 | |
| steel this | |
| 166 | |
| 00:14:12,640 --> 00:14:16,440 | |
| part is to withstand a fluctuating tensile load | |
| 167 | |
| 00:14:16,440 --> 00:14:24,390 | |
| varying from zero to sixteen kilo poundهذه القطع | |
| 168 | |
| 00:14:24,390 --> 00:14:30,310 | |
| لازم تتحمل fluctuating tensile load يعني هاي ال | |
| 169 | |
| 00:14:30,310 --> 00:14:35,170 | |
| bar و | |
| 170 | |
| 00:14:35,170 --> 00:14:46,510 | |
| عليها tensile load F في ال F بتراه من سفر لستاشر | |
| 171 | |
| 00:14:46,510 --> 00:14:48,630 | |
| kilo pound | |
| 172 | |
| 00:14:56,550 --> 00:15:00,490 | |
| because of the ends and fillet radius يعني هو واضح | |
| 173 | |
| 00:15:00,490 --> 00:15:07,950 | |
| انه عشان امسكها مكبر قطر وفيه اندي fillet a | |
| 174 | |
| 00:15:07,950 --> 00:15:15,510 | |
| fatigue stress concentration factor KF بالساوي | |
| 175 | |
| 00:15:15,510 --> 00:15:23,410 | |
| واحد point تمانية خمسة for عشر أو ستة or larger | |
| 176 | |
| 00:15:23,410 --> 00:15:35,770 | |
| lifeيعني عندي infinite life infinite life | |
| 177 | |
| 00:15:35,770 --> 00:15:45,350 | |
| find | |
| 178 | |
| 00:15:45,350 --> 00:15:47,450 | |
| S A and S M | |
| 179 | |
| 00:15:59,870 --> 00:16:04,670 | |
| and the factor of safety guarding against fatigue | |
| 180 | |
| 00:16:04,670 --> 00:16:12,310 | |
| and yielding يعني بده الان اف والان | |
| 181 | |
| 00:16:12,310 --> 00:16:20,970 | |
| واي طيب | |
| 182 | |
| 00:16:32,430 --> 00:16:38,910 | |
| الان ال fatigue failure يعني ابدا أستخدم gear bar | |
| 183 | |
| 00:16:38,910 --> 00:16:47,090 | |
| لو نحكي using gear | |
| 184 | |
| 00:16:47,090 --> 00:16:51,850 | |
| bar هيكون | |
| 185 | |
| 00:16:51,850 --> 00:16:56,370 | |
| عندي sigma a هي | |
| 186 | |
| 00:16:56,370 --> 00:16:56,890 | |
| gear bar | |
| 187 | |
| 00:17:02,420 --> 00:17:16,160 | |
| سيجما اي على اس اي حاكين | |
| 188 | |
| 00:17:16,160 --> 00:17:27,500 | |
| N في سيجما اي على اس اي زائد N في سيجما Mعلى sut | |
| 189 | |
| 00:17:27,500 --> 00:17:36,740 | |
| الكل تربيع بالساوية واحدة هي انما اعطيني ان مباشرة | |
| 190 | |
| 00:17:36,740 --> 00:17:45,220 | |
| انك بالساوية نص sut على sigma m او using الازم | |
| 191 | |
| 00:17:45,220 --> 00:17:54,380 | |
| اللي بتاك هكون | |
| 192 | |
| 00:17:54,380 --> 00:17:54,820 | |
| عندى | |
| 193 | |
| 00:18:05,300 --> 00:18:23,180 | |
| الان سجما A على SE كل تربيع زاد ان سجما M على SY | |
| 194 | |
| 00:18:23,180 --> 00:18:30,440 | |
| كل تربيع بالساوية واحدة | |
| 195 | |
| 00:18:37,830 --> 00:18:40,230 | |
| يعني اول شئ احنا خلينا نحكي عن ال material، هنطلع | |
| 196 | |
| 00:18:40,230 --> 00:18:44,630 | |
| الخصائص .. الخصائص الميكانيكية، واضح بدنا الخصائص | |
| 197 | |
| 00:18:44,630 --> 00:18:48,130 | |
| الميكانيكية لل part عشان نقدر نحسب ال design | |
| 198 | |
| 00:18:48,130 --> 00:18:49,010 | |
| factor of safety | |
| 199 | |
| 00:19:11,110 --> 00:19:24,110 | |
| أظن الف و تونين هذا | |
| 200 | |
| 00:19:24,110 --> 00:19:28,810 | |
| اتنين و عشرين اه انا عارف ايه عشرين هذا واحد و | |
| 201 | |
| 00:19:28,810 --> 00:19:36,210 | |
| عشرين ايه عشرين يعني | |
| 202 | |
| 00:19:36,210 --> 00:19:37,630 | |
| اللي هو الف و خمسين | |
| 203 | |
| 00:19:40,980 --> 00:19:48,640 | |
| called drone معناته عندى هذا ال .. تسعين و تسعة و | |
| 204 | |
| 00:19:48,640 --> 00:19:56,420 | |
| اربعة و نص .. صح؟ called drone .. مية و اربعة و | |
| 205 | |
| 00:19:56,420 --> 00:20:05,520 | |
| تمانين .. اه لان احنا وحدات انجلزية عندى ال SUT | |
| 206 | |
| 00:20:05,520 --> 00:20:08,700 | |
| بستخدام | |
| 207 | |
| 00:20:08,700 --> 00:20:21,380 | |
| ميةكي بي اس اي و ال اس واي يستوي اربعة تمانين هدول | |
| 208 | |
| 00:20:21,380 --> 00:20:28,960 | |
| اي عشرين بلزمنا | |
| 209 | |
| 00:20:28,960 --> 00:20:32,740 | |
| اس اي صح؟ ال اس اي | |
| 210 | |
| 00:20:36,060 --> 00:20:50,120 | |
| سوى KA KB KC KD KE SE' SE' | |
| 211 | |
| 00:20:50,420 --> 00:20:55,160 | |
| شو الساوية نص | |
| 212 | |
| 00:20:55,160 --> 00:21:02,160 | |
| ال SUT يعني هتكون الساوية خمسين | |
| 213 | |
| 00:21:06,030 --> 00:21:10,610 | |
| ال K A Machined ال K A | |
| 214 | |
| 00:21:39,150 --> 00:21:46,910 | |
| بالسواء A S U T ال | |
| 215 | |
| 00:21:46,910 --> 00:21:59,290 | |
| A في حالة ال machine اتنين وال B point | |
| 216 | |
| 00:21:59,290 --> 00:22:05,120 | |
| اتنين و سبعتاشمعنى طيب ان هذه هتساوي اللي هي اتنين | |
| 217 | |
| 00:22:05,120 --> 00:22:13,580 | |
| في مية سالب point متين واحد سبعة هذا | |
| 218 | |
| 00:22:13,580 --> 00:22:23,060 | |
| ال K ايه point سبعة ال | |
| 219 | |
| 00:22:23,060 --> 00:22:23,640 | |
| KB | |
| 220 | |
| 00:22:32,210 --> 00:22:37,910 | |
| طبعا هذا في حالة ال torsion او bending في | |
| 221 | |
| 00:22:37,910 --> 00:22:43,730 | |
| حالة ال axial loading KBA شو يساوي؟ واحد KBA يساوي | |
| 222 | |
| 00:22:43,730 --> 00:22:48,210 | |
| واحد عندي axial loading | |
| 223 | |
| 00:23:02,720 --> 00:23:11,620 | |
| الـ KC إيش الساوية؟ لأن | |
| 224 | |
| 00:23:11,620 --> 00:23:19,580 | |
| K دي و K ايه ماحتي بيرميش واحد ال K دي ساوية K E | |
| 225 | |
| 00:23:19,580 --> 00:23:26,560 | |
| ساوية واحدة معناته ال SE هتكون ساوية K A اللي هو | |
| 226 | |
| 00:23:26,560 --> 00:23:36,050 | |
| point سبعة تلاتة ستةفي واحد في بون تمانية خمسة في | |
| 227 | |
| 00:23:36,050 --> 00:23:46,430 | |
| واحد في واحد في فمسين هذه | |
| 228 | |
| 00:23:46,430 --> 00:23:50,930 | |
| الأسئلة واحد تلاتين | |
| 229 | |
| 00:24:10,450 --> 00:24:21,250 | |
| kpsi الآن عندي ال .. بشكل عام ال stress سيجما عندي | |
| 230 | |
| 00:24:21,250 --> 00:24:26,410 | |
| اكسل اللي هتكون F على area صح هذا ال nominal F على | |
| 231 | |
| 00:24:26,410 --> 00:24:32,240 | |
| areaفي ال KF اذا بدي اخد فرصة stress consideration | |
| 232 | |
| 00:24:32,240 --> 00:24:43,020 | |
| يعني هيكون اربعة | |
| 233 | |
| 00:24:43,020 --> 00:24:58,280 | |
| KF في ال F على Pi D square | |
| 234 | |
| 00:25:02,930 --> 00:25:13,470 | |
| صح؟ الان ال F minimum ايش الساوي؟ سفر وال F | |
| 235 | |
| 00:25:13,470 --> 00:25:18,030 | |
| maximum بالساوي | |
| 236 | |
| 00:25:18,030 --> 00:25:23,890 | |
| ستة عشر معناته | |
| 237 | |
| 00:25:23,890 --> 00:25:36,340 | |
| ال F mean ايش الساوي؟سفر زي ستاشر على اتنين ساوية | |
| 238 | |
| 00:25:36,340 --> 00:25:41,000 | |
| تمانية وال | |
| 239 | |
| 00:25:41,000 --> 00:25:45,440 | |
| F alternating برضه | |
| 240 | |
| 00:25:45,440 --> 00:25:49,800 | |
| ستاشر ناقص سفر على اتنين | |
| 241 | |
| 00:26:04,140 --> 00:26:08,900 | |
| معناته هتكون في الحالة هذه ال F مين بيساوي ال | |
| 242 | |
| 00:26:08,900 --> 00:26:10,700 | |
| alternating معناته ال sigma alternating بيساوي ال | |
| 243 | |
| 00:26:10,700 --> 00:26:13,740 | |
| sigma مين صح؟ هيطلع عند ال sigma alternating | |
| 244 | |
| 00:26:13,740 --> 00:26:20,620 | |
| بيساوي ال sigma مين بتساوي | |
| 245 | |
| 00:26:20,620 --> 00:26:33,500 | |
| اربعة ك F F alternating او F مين على Pi D Square | |
| 246 | |
| 00:26:35,720 --> 00:26:47,000 | |
| هتكون أربع في واحد bond تمانية خمسة في تمانية على | |
| 247 | |
| 00:26:47,000 --> 00:26:59,680 | |
| باي في واحد و نص تاربع تمانية | |
| 248 | |
| 00:26:59,680 --> 00:27:03,980 | |
| bond تلات تمانية KPSI | |
| 249 | |
| 00:27:18,850 --> 00:27:25,550 | |
| انا لو بده اجعل ال criteria هي | |
| 250 | |
| 00:27:25,550 --> 00:27:32,410 | |
| اندي ال sigma مين؟ هي ال sigma alternating صح؟ | |
| 251 | |
| 00:27:32,410 --> 00:27:37,830 | |
| اندي | |
| 252 | |
| 00:27:37,830 --> 00:27:43,430 | |
| هي عشرة هي | |
| 253 | |
| 00:27:43,430 --> 00:27:43,870 | |
| مية | |
| 254 | |
| 00:27:49,850 --> 00:27:55,630 | |
| هذه خمسين هذه | |
| 255 | |
| 00:27:55,630 --> 00:28:11,150 | |
| عشرة عشرين تلاتين اربعين هذه ستين سبعين تمانين | |
| 256 | |
| 00:28:11,150 --> 00:28:13,630 | |
| تسعين | |
| 257 | |
| 00:28:20,810 --> 00:28:27,870 | |
| اتابرها دي مية هاي | |
| 258 | |
| 00:28:27,870 --> 00:28:32,290 | |
| خمسين عشرة | |
| 259 | |
| 00:28:32,290 --> 00:28:42,010 | |
| عشرين تلاتين اربعين عشرة عشرين تلاتين هاي عشرة | |
| 260 | |
| 00:28:42,010 --> 00:28:46,870 | |
| عشرين تلاتين اربعين ستين | |
| 261 | |
| 00:28:54,140 --> 00:28:58,220 | |
| ال SUT اللي | |
| 262 | |
| 00:28:58,220 --> 00:29:07,860 | |
| هي مية صح هاي ال SUT و | |
| 263 | |
| 00:29:07,860 --> 00:29:15,340 | |
| ال SY هاد | |
| 264 | |
| 00:29:15,340 --> 00:29:22,920 | |
| ال SY و ال SE اللي هي واحد تلاتين هاي تلاتين جاي | |
| 265 | |
| 00:29:22,920 --> 00:29:23,160 | |
| هنا | |
| 266 | |
| 00:29:33,630 --> 00:29:40,150 | |
| هي ال SE الجيربا | |
| 267 | |
| 00:29:40,150 --> 00:29:45,430 | |
| جاين non linear بين ال SE و ال SET | |
| 268 | |
| 00:30:01,150 --> 00:30:08,970 | |
| هذه جيربار وهذه ال fatigue failure ال | |
| 269 | |
| 00:30:08,970 --> 00:30:17,310 | |
| yield ال yield عندى هاي تمانين هذا اربعة تمانين | |
| 270 | |
| 00:30:17,310 --> 00:30:20,350 | |
| صح؟ | |
| 271 | |
| 00:30:20,350 --> 00:30:25,530 | |
| as | |
| 272 | |
| 00:30:25,530 --> 00:30:25,810 | |
| wire | |
| 273 | |
| 00:30:34,230 --> 00:30:43,810 | |
| هذا ال yield line وهذا | |
| 274 | |
| 00:30:43,810 --> 00:30:53,230 | |
| ال fatigue طيب | |
| 275 | |
| 00:30:53,230 --> 00:31:00,090 | |
| بدى | |
| 276 | |
| 00:31:00,090 --> 00:31:04,450 | |
| اعرف احنا حسبت ال sigma ايه و sigma مينال سيجمه و | |
| 277 | |
| 00:31:04,450 --> 00:31:12,070 | |
| سيجمه مين؟ تمانية هاي تمانية و تمانية صح؟ | |
| 278 | |
| 00:31:34,930 --> 00:31:41,030 | |
| هذه الـ sigma main التي هي تمانية point تلات | |
| 279 | |
| 00:31:41,030 --> 00:31:47,550 | |
| تمانية هذه ال sigma alternating التي هي تمانية | |
| 280 | |
| 00:31:47,550 --> 00:31:56,050 | |
| point تلات تمانية هذا يعني load line | |
| 281 | |
| 00:32:25,960 --> 00:32:36,020 | |
| لنرجع على ال gear bar يعني هذه هتكون | |
| 282 | |
| 00:32:36,020 --> 00:32:51,340 | |
| هذه | |
| 283 | |
| 00:32:51,340 --> 00:33:00,620 | |
| الحكاية اسمها SM بتاعة الفتيكوها دي S A بتاعة | |
| 284 | |
| 00:33:00,620 --> 00:33:07,940 | |
| الفتيك يعني هذه ال main fatigue strength for this | |
| 285 | |
| 00:33:07,940 --> 00:33:11,940 | |
| loading line هذه ال alternating fatigue strength | |
| 286 | |
| 00:33:11,940 --> 00:33:22,300 | |
| for this load line من | |
| 287 | |
| 00:33:22,300 --> 00:33:22,820 | |
| المعادلة | |
| 288 | |
| 00:33:50,620 --> 00:34:02,280 | |
| ممكن نحصل فتيك factor of safety NF هو | |
| 289 | |
| 00:34:02,280 --> 00:34:06,160 | |
| اشي اللي سواه معادلة | |
| 290 | |
| 00:34:06,160 --> 00:34:14,360 | |
| الخط هذا معروفة عشان نشوف كيف سواه معادلة الخط هذا | |
| 291 | |
| 00:34:14,360 --> 00:34:15,160 | |
| ال filler line | |
| 292 | |
| 00:34:18,140 --> 00:34:23,740 | |
| اللي هو هذه المعادلة ال N Sigma A اللي هي إيش S A | |
| 293 | |
| 00:34:23,740 --> 00:34:32,700 | |
| على S E زاد | |
| 294 | |
| 00:34:32,700 --> 00:34:40,920 | |
| S M على S U T الكل | |
| 295 | |
| 00:34:40,920 --> 00:34:47,400 | |
| تربيع مستوى هذا ال S A و ال S M | |
| 296 | |
| 00:34:50,250 --> 00:34:56,530 | |
| هذه معادلة ال filler line ال load line هذا ال load | |
| 297 | |
| 00:34:56,530 --> 00:35:06,110 | |
| line ال load line هذا جاي بين نقاط صفر و صفر و جاي | |
| 298 | |
| 00:35:06,110 --> 00:35:16,910 | |
| بين sigma M و sigma alternating و جاي بين SM و S | |
| 299 | |
| 00:35:16,910 --> 00:35:21,520 | |
| alternating تلت نقاطيعني المعادلة اللي هو ال line | |
| 300 | |
| 00:35:21,520 --> 00:35:30,360 | |
| هتكون sigma a minus zero على sigma m minus zero | |
| 301 | |
| 00:35:30,360 --> 00:35:35,120 | |
| بالساوية | |
| 302 | |
| 00:35:35,120 --> 00:35:44,760 | |
| S a على S m خلنا نحكي انها ساوية R، R هي ال slope | |
| 303 | |
| 00:35:44,760 --> 00:35:45,460 | |
| بتاعة الخطة | |
| 304 | |
| 00:35:51,540 --> 00:35:59,560 | |
| في الحالة هذه احنا عندنا R بساوة Sigma A على Sigma | |
| 305 | |
| 00:35:59,560 --> 00:36:19,180 | |
| M بساوة واحدة صح عند | |
| 306 | |
| 00:36:19,180 --> 00:36:31,560 | |
| النقطة هذهعند نقطة هذه بتكون نقطة هذه يتم تحقيقها | |
| 307 | |
| 00:36:31,560 --> 00:36:38,120 | |
| من معادة الخط هذا و معادة ال curve هذا صح؟ منته لو | |
| 308 | |
| 00:36:38,120 --> 00:36:45,860 | |
| عوضت عن هذه معادلة واحد هذه معادلة اتنين من اتنين | |
| 309 | |
| 00:36:51,060 --> 00:36:57,020 | |
| لو حكيت ان S A بساوة | |
| 310 | |
| 00:36:57,020 --> 00:37:02,800 | |
| R S M | |
| 311 | |
| 00:37:02,800 --> 00:37:12,820 | |
| R S M و عوضتها هنا بس راندي هنا عوضت في واحد R S M | |
| 312 | |
| 00:37:12,820 --> 00:37:16,040 | |
| على | |
| 313 | |
| 00:37:16,040 --> 00:37:16,780 | |
| S E | |
| 314 | |
| 00:37:22,170 --> 00:37:29,470 | |
| بتساوى زائد RSM | |
| 315 | |
| 00:37:29,470 --> 00:37:35,770 | |
| على SUT لكل | |
| 316 | |
| 00:37:35,770 --> 00:37:43,350 | |
| تربيع ساوى واحد نعم | |
| 317 | |
| 00:37:43,350 --> 00:37:45,590 | |
| ال .. ال .. | |
| 318 | |
| 00:37:49,640 --> 00:37:57,240 | |
| ها دي S A بيوضع ان S A اللي هي R في S M اه | |
| 319 | |
| 00:37:57,240 --> 00:38:08,640 | |
| اه صحيح مافيش R زي ما هي S M الصحيح ال | |
| 320 | |
| 00:38:08,640 --> 00:38:14,920 | |
| S M اللي هو نحكي ال factor safety N بس هو ال S M | |
| 321 | |
| 00:38:17,380 --> 00:38:24,540 | |
| على sigma M صح؟ يعني | |
| 322 | |
| 00:38:24,540 --> 00:38:31,520 | |
| SM بستوى N Sigma M يعني هنا حسينا اندي R في | |
| 323 | |
| 00:38:31,520 --> 00:38:42,400 | |
| N F Sigma M على SE زائد | |
| 324 | |
| 00:38:42,400 --> 00:38:45,240 | |
| N F | |
| 325 | |
| 00:38:48,070 --> 00:39:00,870 | |
| Sigma M على S U T كل تربيع تساوي واحد ال | |
| 326 | |
| 00:39:00,870 --> 00:39:13,390 | |
| R ايه بتساوي؟ واحد ال R بتساوي واحد مش واحد ال R | |
| 327 | |
| 00:39:13,390 --> 00:39:18,200 | |
| بتساوياللي هي هذه .. هذه واحد حالة خاصة الحالة | |
| 328 | |
| 00:39:18,200 --> 00:39:25,000 | |
| تاعتنا واحد ال R بعوض عنها Sigma A على Sigma M | |
| 329 | |
| 00:39:25,000 --> 00:39:31,440 | |
| بمعنى انت بيصير مجهول عندك ويحسب ال NF ال NF هذي | |
| 330 | |
| 00:39:31,440 --> 00:39:36,660 | |
| معادلة إيش؟ عندي في term تربيع جاء على صيغة اللي | |
| 331 | |
| 00:39:36,660 --> 00:39:47,710 | |
| هي AX تربيع زائد BX زائد C بالساعة وصفرومنها حسب | |
| 332 | |
| 00:39:47,710 --> 00:39:52,370 | |
| إيش ال enough لإن هو هذي التربيع و هذا مش تربيع و | |
| 333 | |
| 00:39:52,370 --> 00:39:56,510 | |
| هذا ال constant term و منها بيحسب ال X اللي هي | |
| 334 | |
| 00:39:56,510 --> 00:39:58,950 | |
| بتعطينا المعادلة هذه يعني شفتوا الفكرة بتاعتها ال | |
| 335 | |
| 00:39:58,950 --> 00:40:05,590 | |
| enough اللي هي بس واحد على اتنين S U T يعني هتكون | |
| 336 | |
| 00:40:05,590 --> 00:40:07,890 | |
| ان دي ال enough الحالة هذه | |
| 337 | |
| 00:40:15,010 --> 00:40:27,230 | |
| ن اف بحالة جيربار بالساعة نص ف | |
| 338 | |
| 00:40:27,230 --> 00:40:32,770 | |
| س يو تي على | |
| 339 | |
| 00:40:32,770 --> 00:40:47,690 | |
| سيجما ام الكل تربيع فسيجما اي على س ايفي minus | |
| 340 | |
| 00:40:47,690 --> 00:40:54,830 | |
| واحد زائد جزر التربيع لواحد | |
| 341 | |
| 00:40:54,830 --> 00:40:58,450 | |
| زائد | |
| 342 | |
| 00:40:58,450 --> 00:41:05,170 | |
| اتنين sigma M SE على | |
| 343 | |
| 00:41:14,310 --> 00:41:22,430 | |
| العوض يعني هيكون عنده نص في | |
| 344 | |
| 00:41:22,430 --> 00:41:25,650 | |
| ال | |
| 345 | |
| 00:41:25,650 --> 00:41:31,670 | |
| SUT اللي هي مية على | |
| 346 | |
| 00:41:31,670 --> 00:41:37,550 | |
| تمانية point تلات تمانية الكل | |
| 347 | |
| 00:41:37,550 --> 00:41:48,600 | |
| تربيعفي تمانية point تلاتة تمانية على ال S A على | |
| 348 | |
| 00:41:48,600 --> 00:41:57,900 | |
| واحد تلاتين point اتنين تمانية في ناقص واحد زائد | |
| 349 | |
| 00:41:57,900 --> 00:42:05,560 | |
| جزر التربيعي لواحد زائد اتنين في تمانية point | |
| 350 | |
| 00:42:05,560 --> 00:42:13,820 | |
| تلاتة تمانيةهذه لـ Sigma M في واحد تلاتين بون | |
| 351 | |
| 00:42:13,820 --> 00:42:21,960 | |
| تمانية وعشرين على مية في تمانية بون تلاتة تمانية | |
| 352 | |
| 00:42:21,960 --> 00:42:33,260 | |
| هو الكل ترجع هنا بنحسب الان اف طبعا | |
| 353 | |
| 00:42:37,460 --> 00:42:41,180 | |
| إذا طلع الأناف أكبر أو يستوي واحد شغلنا 100% صحيح | |
| 354 | |
| 00:42:41,180 --> 00:42:45,580 | |
| إذا مش .. طلعت أقل من واحد بدأنا نعمل شغل تاعنا | |
| 355 | |
| 00:42:45,580 --> 00:42:54,520 | |
| نجيله بعد شوية تلاتة point أربع | |
| 356 | |
| 00:42:54,520 --> 00:43:00,840 | |
| ال factor of safety طيب | |
| 357 | |
| 00:43:00,840 --> 00:43:03,620 | |
| اللي ييه ال factor of safety | |
| 358 | |
| 00:43:06,620 --> 00:43:13,260 | |
| بدي احسب انا SM هذه هذي | |
| 359 | |
| 00:43:13,260 --> 00:43:19,280 | |
| SM بتاعة ال yield هذي | |
| 360 | |
| 00:43:19,280 --> 00:43:28,260 | |
| SA بتاعة ال yield اذا اخدت المثلث هذا هذا المثلث | |
| 361 | |
| 00:43:28,260 --> 00:43:31,680 | |
| مع | |
| 362 | |
| 00:43:31,680 --> 00:43:32,780 | |
| المثلث الكبير | |
| 363 | |
| 00:43:45,740 --> 00:43:51,740 | |
| النقطة هذه تقاطع معادة الخط هذا الخط هذا جاي بين S | |
| 364 | |
| 00:43:51,740 --> 00:43:58,760 | |
| Y و S Y صح الخط هذا جاي بين S يعني معادة ال lead | |
| 365 | |
| 00:43:58,760 --> 00:44:13,120 | |
| line هتكون اللي هي S A على S E زائد S M على S Y | |
| 366 | |
| 00:44:16,390 --> 00:44:22,790 | |
| زاد SM على SY بالسواء | |
| 367 | |
| 00:44:22,790 --> 00:44:36,450 | |
| واحد هذا الخط و هذا الخط معدلته اللى عندى انا اللى | |
| 368 | |
| 00:44:36,450 --> 00:44:53,190 | |
| هو Sigma A على Sigma M بالسواء SAعلى ايش SM يعني | |
| 369 | |
| 00:44:53,190 --> 00:44:57,850 | |
| SA هتكون | |
| 370 | |
| 00:44:57,850 --> 00:45:10,110 | |
| تساوي SM في Sigma A على Sigma M نعوض | |
| 371 | |
| 00:45:10,110 --> 00:45:10,830 | |
| هنا عن SA | |
| 372 | |
| 00:45:14,270 --> 00:45:22,190 | |
| S A اللي هي S M في | |
| 373 | |
| 00:45:22,190 --> 00:45:32,250 | |
| Sigma A على Sigma M S | |
| 374 | |
| 00:45:32,250 --> 00:45:36,930 | |
| Y على Sigma | |
| 375 | |
| 00:45:36,930 --> 00:45:40,710 | |
| M S Y | |
| 376 | |
| 00:45:44,030 --> 00:45:51,650 | |
| زائد SM على SY بالساعة واحدة يعني اذا ضربت طرفين | |
| 377 | |
| 00:45:51,650 --> 00:45:57,690 | |
| بـ SY بتروح الـ SY بسير | |
| 378 | |
| 00:45:57,690 --> 00:46:07,970 | |
| على الجهة التانية SY يعني | |
| 379 | |
| 00:46:07,970 --> 00:46:16,960 | |
| خود عام مشترك اللي هوsm هيكون | |
| 380 | |
| 00:46:16,960 --> 00:46:20,560 | |
| عندى | |
| 381 | |
| 00:46:20,560 --> 00:46:32,500 | |
| sigma a على sigma m زائد واحد صح بتسوى | |
| 382 | |
| 00:46:32,500 --> 00:46:36,260 | |
| sy يعني | |
| 383 | |
| 00:46:36,260 --> 00:46:40,940 | |
| n او sm بتاعة ال yield | |
| 384 | |
| 00:46:52,490 --> 00:47:00,690 | |
| بتساوي بتساوي Sigma Y Sigma M SY | |
| 385 | |
| 00:47:00,690 --> 00:47:12,990 | |
| على Sigma A زائد Sigma M هذه الاس ام منعته | |
| 386 | |
| 00:47:16,830 --> 00:47:21,690 | |
| هتساوي نه مش | |
| 387 | |
| 00:47:21,690 --> 00:47:25,030 | |
| فاهم | |
| 388 | |
| 00:47:25,030 --> 00:47:31,610 | |
| ماشي انا بحل بشكل عام حتكون | |
| 389 | |
| 00:47:31,610 --> 00:47:40,810 | |
| هتساوي SY على 2 في حالتنا صح؟ بيساوي SY على | |
| 390 | |
| 00:47:40,810 --> 00:47:46,460 | |
| 2 لإن هو ده جاي مائل بزاوية 45هكون في النص الخط S | |
| 391 | |
| 00:47:46,460 --> 00:47:53,420 | |
| Y على اتنين يعني هكون اربعة تمانين على اتنين اتنين | |
| 392 | |
| 00:47:53,420 --> 00:48:03,120 | |
| واربعين كيلو pound per square inch معناه ال N Y ال | |
| 393 | |
| 00:48:03,120 --> 00:48:11,680 | |
| N Y هتكون تستاوي الاسئم بتاعة ال yield على ال | |
| 394 | |
| 00:48:11,680 --> 00:48:12,260 | |
| sigma M | |
| 395 | |
| 00:48:15,170 --> 00:48:23,910 | |
| اللي هي اتنين و اربعين على تمانية point تلال | |
| 396 | |
| 00:48:23,910 --> 00:48:28,870 | |
| تمانية بطلع | |
| 397 | |
| 00:48:28,870 --> 00:48:39,850 | |
| خمسة أو اشي مظبوط خمسة point zero واحد مبين | |
| 398 | |
| 00:48:39,850 --> 00:48:44,780 | |
| يعنيمن .. منبين ان ال factor of safety بتاع ال | |
| 399 | |
| 00:48:44,780 --> 00:48:50,760 | |
| fatigue أقل و انا ماتوقع أصير .. يعني في الحالة دي | |
| 400 | |
| 00:48:50,760 --> 00:48:55,300 | |
| أقل من ارثم بيبين معايا إذا في ده أفحص لليد و لا | |
| 401 | |
| 00:48:55,300 --> 00:49:00,060 | |
| مش ده أفحص لليد في حالتنا ك designer بلزمنيش أفحص | |
| 402 | |
| 00:49:00,060 --> 00:49:04,520 | |
| لليد لأن ال factor of safety أعلى في ال yield أعلى | |
| 403 | |
| 00:49:04,520 --> 00:49:08,420 | |
| من في حالة الفتيك طبعا نفس الطريقة بنحل في حالة | |
| 404 | |
| 00:49:09,210 --> 00:49:15,430 | |
| القزمة بس المعادلة تختلف example ستة احدة هتقراوه | |
| 405 | |
| 00:49:15,430 --> 00:49:22,070 | |
| في الكتاب اللي بختلف ماشي | |
| 406 | |
| 00:49:22,070 --> 00:49:25,510 | |
| يعني .. يعني تقراوه لحالكوا عشان اخش موضوع جديد | |
| 407 | |
| 00:49:25,510 --> 00:49:27,070 | |
| المحاضرة عشان اعطيكوا العافية | |