µÃÈçϽá¹û£º
±í3. ·çËÙΪ36msʱµÄÇó½â½á¹û h1 h2 º£Ë®Éî¶È êÁ´Ë®Æ½Çã½Ç ¸ÖͰµÄÇã½Ç ËùÓÃÎÞµµÁ´»·¸öÊý 0.759m 0.7810m 17.7796m 17.7796¡ã 8.1268¡ã 210 ¸Ö¹Ü1µÄÇã½Ç ¸Ö¹Ü2µÄÇã½Ç ¸Ö¹Ü3µÄÇã½Ç ¸Ö¹Ü4µÄÇã½Ç Óζ¯ÇøÓò°ë¾¶ ¸¡±êµÄ³ÔË®Éî¶È 7.8999¡ã 7.9424¡ã 7.9853¡ã 8.0287¡ã 18.3712m 0.77m µÃµ½ÃªÁ´µÄÐÎ×´Èçͼ14Ëùʾ£º
ͼ14.·çËÙΪ36msʱêÁ´µÄÐÎ×´
´Ëʱ£¬ÃªÁ´Ä©¶ËÓëêµÄÁ´½Ó´¦µÄÇÐÏß·½ÏòÓ뺣´²µÄ¼Ð½ÇΪ17.7796¶È£¬³¬¹ýÁË16¶È£¬¸ÖͰµÄÇãб½Ç¶È(¸ÖͰÓëÊúÖ±ÏߵļнÇ)Ϊ8.1268¶È£¬³¬¹ý5¶È£¬ÒѾ²»Äܹ»´ïµ½Æ½ºâ״̬£¬Òò´ËÐ迼Âǵ÷½ÚÖØÎïÇòÖÊÁ¿£¬Ê¹ÆäÖØÐ´ﵽƽºâ״̬¡£ 4.4.2 »ùÓÚÖØÎïÇòÖÊÁ¿µÄ¶¨³£ÏµÍ³×îÓÅϵ²´Ä£ÐÍ
µ±·çËÙ´ïµ½36msʱ£¬Ïµ²´ÏµÍ³ÒѾ²»ÔÙÂú×ã½Ç¶ÈµÄÒªÇ󣬴Ӷø²»ÔÙ´¦ÓÚÆ½ºâ״̬£¬Òò´ËÎÒÃÇ¿¼Âǵ÷ÕûÖØÎïÇòÖÊÁ¿¡£ÔÚ´ËÎÒÃǼÙÉ躣ˮ¾²Ö¹£¬¿¼ÂÇˮƽ·çËÙ¡¢Ë®ÉêÁ´Ðͺ𢳤¶ÈµÈ¾ùΪ¶¨³£Êý£¬»ùÓÚÖØÎïÇòÖÊÁ¿µÄÑ¡Ôñ£¬½¨Á¢Á˵¥¾ö²ß±äÁ¿µÄ¶àÄ¿±ê×îÓÅϵ²´Ä£ÐÍ¡£
4.4.2.1Ä¿±êº¯Êý
£¨Ò»£©¸¡±êµÄ³ÔË®Éî¶È¾¡¿ÉÄÜС£º
minmh; £¨45£©
h1?h2£¬¼´¸¡±êÁ½±ß½þË®³¤¶ÈµÄƽ¾ùÖµ£» 2£¨¶þ£©Óζ¯ÇøÓò¾¡¿ÉÄÜС£¬¼´Óζ¯°ë¾¶¾¡¿ÉÄÜ×îС£º
ÆäÖгÔË®Éî¶Èh?minmX £¨46£©
ÆäÖÐÓζ¯°ë¾¶X?XA?XB?XC?XD(¼û29ʽ)£» £¨Èý£©¸ÖͰµÄÇãб½Ç¶È¾¡¿ÉÄÜС£»
minm?2??C £¨47£©
17
ÆäÖÐ?C±íʾ¸ÖͰÓëË®Æ½ÃæµÄ¼Ð½Ç¡£
4.4.2.2 Ô¼ÊøÌõ¼þ
(Ò»)º£Ë®µÄÉî¶ÈÔ¼Êø£¬¼´Æ½ºâ״̬ÏÂÕû¸öϵ²´ÏµÍ³µÄÊúÖ±¸ß¶ÈÖ®ºÍÓ¦µÈÓÚË®ÉîH£¬ÓÐ
4h1?h2sin?A??LBsin(?Bi)?LCsin?C?yD?H, £¨48£© 2iÆäÖÐ
h1?h2sin?A±íʾ¸¡±êµ×ÃæÖáÐĵ½º£Æ½ÃæµÄ¾àÀ룬h1,h2·Ö±ð±íʾ¸¡±êÁ½±ß½þÈë24i?1Ë®Öеij¤¶È£¬?A¸¡±êµÄÇãб½Ç¶È£¬?LBsin(?Bi)±íʾ4¸ö¸Ö¹ÜÔÚË®Öеĸ߶Ⱥͣ¬LB±íʾÿ½Ú¸Ö¹ÜµÄ³¤¶È£¬?Bi±íʾµÚi½Ú¸Ö¹ÜµÄÇãб½Ç¶È£»LC±íʾ¸ÖͰµÄ³¤¶È£¬?C±íʾ¸ÖͰµÄÇãб½Ç¶È£¬yD±íʾêÁ´ÊúÖ±·½ÏòµÄ¸ß¶È¡£
£¨¶þ£©ÃªÁ´µ×¶ËÀÁ¦µÄ¼Ð½ÇÔ¼Êø£¬¼´ÃªÁ´ÔÚêµãÓ뺣´²µÄ¼Ð½Ç²»³¬¹ý16¶È£¬ÓÐ
?(s)??D??max, £¨49£©
NÓÉÎÊÌâ1¿ÉÖª£¬T,?,sÂú×ãÈçÏÂ΢·Ö·½³Ì×é
ÆäÖÐ?DN?d??Dg?cos???dsT, £¨50£© ?dT???Dgsin??ds?±íʾêÁ´ÔÚêµãÓ뺣´²µÄ¼Ð½Ç£¬?max±íʾʹµÃê²»»¬¶¯Ê±£¬ÃªÁ´ÔÚêµãÓë
º£´²µÄ×î´ó¼Ð½Ç¡£
£¨Èý£©Æ½ºâÔ¼ÊøÌõ¼þ£¬¼´´ïµ½ÏµÍ³¸÷²¿·ÖÁ¦ºÍÁ¦¾ØÆ½ºâµÄ¸÷µÈÊ½Ô¼ÊøÌõ¼þ£¬°üÀ¨Ê½£¿
×ÛÉÏ£ºÎÒÃǽ¨Á¢ÁË»ùÓÚÖØÎïÇòÖÊÁ¿µÄ¶àÄ¿±ê×îÓÅϵ²´Ä£ÐÍÈçÏÂ
minh;minX;£¨51£©
?min??C;2
4h1?h2??H?2sin?A??LBsin(?Bi)?LCsin?C?yDi????? £¨52£© max?DN??Á¦¼°Á¦¾ØÆ½ºâÔ¼ÊøÌõ¼þ(1)-(23)
4.5ÎÊÌâ2 µÄÄ£ÐÍÇó½â 4.5.1¶àÄ¿±êµÄת»»
¶ÔÓÚÎÊÌâ2£¬ÕâÊÇÒ»¸ö¶àÄ¿±êµÄÓÅ»¯ÎÊÌ⣬²»Äܹ»Ö±½Ó½øÐÐÇó½â£¬ÐèÒª°Ñ¶àÄ¿±êת»¯Îªµ¥Ä¿±ê½øÐÐÇó½â¡£¾ßÌå·½·¨Îª£º
ÏȼÆË㵥Ŀ±ê
?min??C£¨53£©
2
18
4h1?h2??H?2sin?A??LBsin(?Bi)?LCsin?C?yDi????? £¨54£© max?DN??Á¦¼°Á¦¾ØÆ½ºâÔ¼ÊøÌõ¼þ(1)-(23)?µÃµ½Çã½ÇµÄ×îÓÅÖµ?* £¬ÔÙ½«?*??5×÷ÎªÔ¼ÊøÌõ¼þ¼ÓÈëµ½ÓÅ»¯ÎÊÌâÀïÃæ£¬ÕâÑù
2ÎÊÌâת»¯ÎªË«Ä¿±êÓÅ»¯ÎÊÌâ¡£
minh;£¨55£©
minX;
4h1?h2??H?2sin?A??LBsin(?Bi)?LCsin?C?yDi???DN??max (56)???*???5?2 ??Á¦¼°Á¦¾ØÆ½ºâÔ¼ÊøÌõ¼þ(1)-(23) ÔÙ¿¼ÂdzÔË®Éî¶ÈµÄÓÅ»¯£¬ÀûÓÃÀàËÆµÄ·½·¨µÃµ½Æä×îÓÅÖµ×÷ÎªÔ¼ÊøÌõ¼þ£¬¼´£º
minX;(57)
4h1?h2??H?2sin?A??LBsin(?Bi)?LCsin?C?yDi???DN??max? (58)?*????5??*2 ?h?h?2?Á¦¼°Á¦¾ØÆ½ºâÔ¼ÊøÌõ¼þ(1)-(23)?4.5.2 ¿ÉÐнâµÄ·¶Î§
ÒòΪ¸ÃÎÊËù¸øµÄ·çËÙ±ä´ó£¬ÔÚ³õʼµÄÌõ¼þϲ»ÄÜÔٵõ½¿ÉÐнâÁË¡£ËùÒÔÕâÀï³ýÁ˸ø¶¨h1¡¢h2µÄÖµ£¬»¹ÐèÒª¸ø¶¨ÖØÎïÇòµÄÖÊÁ¿¡£ÔÚÎÊÌâÒ»ÖÖÖØÁ¦ÇòÖÊÁ¿Îª1200kgÒѾ²»ÄÜÂú×ãÌâĿҪÇó£¬ËùÒÔÖØÎïÇòµÄÖØÁ¦Ó¦¸ÃÂú×㣺GC1?12000N¡£ÎªÁËÕÒµ½ÖØÎïÇòÖØÁ¦µÄÉÏÏÞ£¬Ê×ÏȼÙÉèÖ»ÓÐÖØÎïÇòµÄÖØÁ¦×÷Óã¬ÇÒ¸¡±êÍêÈ«ÑÍûÔÚË®ÖС£´Ëʱ£¬¶Ô¸¡±ê½øÐÐÊÜÁ¦·ÖÎö£¬µÃµ½µÄÊÜÁ¦·ÖÎöͼÈçͼ15Ëùʾ£º
19
ͼ15.¸¡±êµÄÊÜÁ¦·ÖÎöͼ
¸ù¾ÝÊÜÁ¦·ÖÎö£¬µ±¸¡±ê´¦ÓÚÆ½ºâ״̬ʱÓУº
FbuyantA?GA?GC1 (59) ÆäÖУ¬FbuoyantA??gVoverflowA£» ÓÉÓÚ¸¡±êÍêÈ«±»ÑÍû£¬ËùÒÔÓУº
VoverflowA??rA2lA?6.28m3
Ôò£º
FbuoyantA?63082.6N
´Ëʱ£¬Òò´ËÉè¶¨ÖØÎïÇòÖØÁ¦µÄȡֵ·¶Î§ÊÇ12000N?GC1?53082.6N¡£GC1?53082.6N¡£µ±ÖØÎïÇòÖØÁ¦µÄÖµ½Ó½üÉÏÏÞֵʱ£¬¸¡±ê½Ó½ü±»ÍêÈ«ÑÍû£¬´Ëʱ¸¡±êÊÜ·ç´µµÄÃæ»ýС£¬¼´·çÁ¦Ð¡£¬Õû¸öϵͳÔÚˮƽ·½ÏòÖ»ÊÜ·çÁ¦ºÍêÉϵÄĦ²ÁÁ¦µÄ×÷Óã¬ÇÒÕâÁ½¸öÁ¦ÊÇÒ»¶ÔƽºâÁ¦£¬µ±·çÁ¦½ÏСʱ£¬ÏµÍ³½«²»»áÔÚˮƽ·½ÏòÉÏÒÆ¶¯£¬µ±¸¡±êÍêÈ«³Áûʱ£¬ÏµÍ³½«ÍêÈ«²»ÔÚˮƽ·½ÏòÒÆ¶¯£¬Õâʱ¸ÖͰÇãб½Ç¶È´ïµ½×îСΪ0¶È£¬ÃªÁ´´¦ÓÚËɳÚ״̬£¬ÇÒ´ËʱΪƽºâ״̬¡£
4.5.3ÎÊÌâ2 µÄ¾ßÌåËã·¨²½Öè
Çó½âµÄ»ù±¾Ë¼Â·Í¬ÎÊÌâÒ»ÊÇÀàËÆµÄ£¬»¹ÊDzÉÓÃËÑË÷Ëã·¨¡£µ«ÊÇÓÉÓÚ±äÁ¿¸öÊýÔö¼ÓÁËÒ»¸ö£¬ËÑË÷µÄ·¶Î§ºÍ¼ÆËãÁ¿½«´ó´óÔö¼Ó£¬Èç¹û»¹²ÉÓÃÎÊÌâÒ»µÄ¶¨²½³¤ËÑË÷µÄ»°£¬¼ÆËãʱ¼äºÍ½á¹û¿ÉÄÜÄÑÒÔ±£Ö¤¡£¹Ê²ÉÓñ䲽³¤ËÑË÷Ëã·¨£¬¾ßÌå²½ÖèΪ£º
£¨1£©ÔÚËÑË÷²ÎÊýµÄÓÐЧ·¶Î§ÄÚ£¬¸ø¶¨Ò»¸ö½Ï´óµÄ²½³¤?G,?h1,?h2£¨±ÈÈç[5,0.1,0.1]£©£¬ÓëÎÊÌâÒ»µÄÇó½â·½·¨Ò»Ñù£¬µÃµ½¶ÔÓ¦µÄH,?DN£»
£¨2£©ÅжÏÈç¹ûͬʱÂú×ãÌõ¼þH?18??£¬£¨?È¡½ÏСֵ£¬±ÈÈç0.1£©ºÍ0??DN?16£¬
?£» ÔòÊä³ö½á¹û²¢½áÊø¼ÆË㣻Èç¹û²»Âú×㣬Ôò¼ÇÏÂ×î½Ó½üÅжÏÌõ¼þµÄÒ»×éG?,h1?,h2?Ϊеijõʼµã£¬?£¨3£©ÒÔG?,h1?,h2Ñ¡¶¨Ò»¸ö½ÏСµÄ²½³¤?G?,?h1?,?h2£¨±ÈÈç[1,0.01,0.01]£©£¬
20
Ïà¹ØÍÆ¼ö£º