ÀíÂÛÁ¦Ñ§Á·Ï°²áÌâ¼°½â´ð ÏÂÔØ±¾ÎÄ

ÀíÂÛÁ¦Ñ§B£¨1) Á·Ï°²á 32ѧʱ À¥Ã÷Àí¹¤´óѧ

רҵ ѧºÅ ÐÕÃû ÈÕÆÚ ³É¼¨

3.3.6 ÇóͼʾÐͲĽØÃæÐÎÐĵÄ×ø±ê¡£[´ð°¸£º(a) xC=0£¬yC=6.07©L£»(b) xC=11©L£¬yC=0©L] (b) (a)

(a) ½â£ºÓɾùÖÊÎïÌåµÄÐÎÐÄ×ø±ê¹«Ê½£¨3-30£©Ê½ (b) ½â£ºÓɾùÖÊÎïÌåµÄÐÎÐÄ×ø±ê¹«Ê½£¨3-30£©Ê½

Ó÷ָ£º ÓɶԳÆÐԵ㺠xc?0ÓɶԳÆÐԵ㺠yc?0ÓøºÃæ»ý·¨£º AixCiA1xc1?A2xc2?A3xc3AyAy?AyiCix??2c2cyc? ?1c1AiA1?A2?A3AiA1?A2

?172?(?18?14)?(3?7)20?2?1?20?2?12?15?2?2324?17?11mm???6.08mm 20?2?20?2?15?224?17?(?18?14)

3.3.7¾ùÖÊ¿é³ß´çÈçͼËùʾ£¬ÇóÆäÖØÐĵÄλÖᣠ[´ð°¸£º xC=23.08mm£¬yC=38.46©L, zC=-28.08©L]

???? ViyciV1yc1?V2yc2y?? cViV1?V2

80?40?60?40?40?40?10?20 ? 80?40?60?40?40?10½â£ºÓɾùÖÊÎïÌåµÄÐÎÐÄ×ø±ê¹«Ê½£¨3-30£©Ê½

Ó÷ָ£º

xc???Vx?Viici?V1xc1?V2xc2V1?V280?40?60?20?40?40?10?6080?40?60?40?40?10?23.08mmzc?????Vz?Viici?V1zc1?V2zc2V1?V280?40?60?(?30)?40?40?10?(?5)80?40?60?40?40?10?38.46mm17

??28.08mmÀíÂÛÁ¦Ñ§B£¨1) Á·Ï°²á 32ѧʱ À¥Ã÷Àí¹¤´óѧ

רҵ ѧºÅ ÐÕÃû ÈÕÆÚ ³É¼¨

µÚËÄÕ Ħ ²Á

Ò»¡¢ ÊÇ·ÇÅжÏÌâ

4.1.1 Ö»ÒªÊÜÁ¦ÎïÌå´¦ÓÚÆ½ºâ״̬£¬Ä¦²ÁÁ¦µÄ´óСһ¶¨ÊÇF= ?sFN¡£ ( ¡Á ) 4.1.2 ÔÚ¿¼ÂÇ»¬¶¯Óë¹ö¶¯¹²´æµÄÎÊÌâÖУ¬»¬¶¯Ä¦²ÁÁ¦²»ÄÜÓ¦ÓÃF= ?sFNÀ´´úÌæ¡£ ( ¡Å ) 4.1.3 µ±¿¼ÂÇĦ²Áʱ£¬Ö§³ÐÃæ¶ÔÎïÌåµÄ·¨Ïò·´Á¦FNºÍĦ²ÁÁ¦FsµÄºÏÁ¦FRÓë·¨ÏߵļнǦճÆÎªÄ¦²Á½Ç¡£ ( ¡Á ) 4.1.4 ¹ö¶¯Ä¦²ÁÁ¦Å¼¾ØÊÇÓÉÓÚÏ໥½Ó´¥µÄÎïÌå±íÃæ´Ö²ÚËù²úÉúµÄ¡££¨ÎïÌåÐα䣩 ( ¡Á )

¶þ¡¢ Ìî¿ÕÌâ

4.2.1 ¿¼ÂÇĦ²ÁʱÎïÌåµÄƽºâÎÊÌ⣬ÆäÌØµãÔÚÓÚ P116 (1)£¬(2)£¬(3) ¡£

4.2.2 Îï¿ìÖØP£¬·ÅÖÃÔÚ´Ö²ÚµÄË®Æ½ÃæÉÏ£¬½Ó´¥´¦µÄĦ²ÁϵÊýΪfs£¬ÒªÊ¹Îï¿éÑØË®Æ½ÃæÏòÓÒ»¬¶¯£¬¿ÉÑØOA·½ÏòÊ©¼ÓÀ­Á¦F1Èçͼ4.1Ëùʾ£¬Ò²¿ÉÑØBO·½ÏòÊ©¼ÓÍÆÁ¦F2ÈçͼËùʾ£¬Á½ÖÖÇé¿ö±È½Ïͼ £¨a£© ËùʾµÄÇéÐθüÊ¡Á¦¡£ 4.2.3²ÄÁÏÏàͬ¡¢¹â½à¶ÈÏàͬµÄƽƤ´øºÍÈý½ÇƤ´ø,Èçͼ4.2Ëùʾ,ÔÚÏàͬѹÁ¦F×÷ÓÃÏÂ, Èý½Ç Ƥ´øµÄ×î´óĦ²ÁÁ¦´óÓÚ Æ½ Ƥ´øµÄ×î´óĦ²ÁÁ¦¡£

F1 F2 P P ??O O (a) (b)

ͼ4.1 ͼ4.2

Èý¡¢Ñ¡ÔñÌâ

4.3.1Èçͼ4.3Ëùʾ£¬ÒÑÖªOA¸ËÖØW£¬Îï¿éMÖØP¡£¸ËÓëÎï¿é¼äÓÐĦ²Á£¬¶øÎïÌåÓëµØÃæ¼äµÄĦ²ÁÂÔÈ¥²»¼Æ¡£µ±Ë®Æ½Á¦FÔö´ó¶øÎï¿éÈÔ±£³Öƽºâʱ£¬¸Ë¶ÔÎï¿éMµÄÕýѹÁ¦ B ¡£

A¡¢ÓÉС±ä´ó£» B¡¢ÓÉ´ó±äС£» C¡¢²»±ä¡£

4.3.2Èçͼ4.4Ëùʾ£¬Îï¿éÖØ5kN£¬ÓëË®Æ½Ãæ¼äµÄĦ²Á½ÇΪ¦Õm=35o£¬½ñÓÃÓëǦ´¹Ïß³É60o½ÇµÄÁ¦F=5kNÍÆ¶¯Îï¿é£¬ÔòÎï¿é½« A ¡£

¡ß ¦Õ = 30 0 £¼¦Õf = 900 - ¦Õm = 550

A¡¢²»¶¯£» B¡¢»¬¶¯£» F O C¡¢´¦ÓÚÁÙ½ç״̬£» 60o D¡¢»¬¶¯Óë·ñ²»ÄÜÈ·¶¨¡£

F 600 A F W M FR ¦Õ

Ŷ18

ÀíÂÛÁ¦Ñ§B£¨1) Á·Ï°²á 32ѧʱ À¥Ã÷Àí¹¤´óѧ

רҵ ѧºÅ ÐÕÃû ÈÕÆÚ ³É¼¨

ͼ4.3£¬ ͼ4.4 ËÄ¡¢¼ÆËãÌâ

4.4.1 Ðü±ÛÍмܵ¯»ÉKµÄÀ­Á¦F=8N£¬Îï¿éAÓëBOÁº¼äµÄ¾²Ä¦²ÁϵÊýfs=0.2£¬µ±?=30oʱ£¬ÊÔÎÊÎï¿éAÊÇ·ñƽºâ£¿£¨´ð°¸£ºFs=0.66N£©

½â£ºÈ¡Îï¿éAΪÑо¿¶ÔÏó

O

3B ?F?8N?FTcos??10??8.66N

2? A K ¡à Îï¿éAÓÐÏòÓÒ»¬¶¯µÄÇ÷ÊÆ£¬FSÖ¸Ïò×ó±ß£»

3N 10N X?0-F?F?Fcos??0 FNFT?FS??F?FTcos??0.66Ny FS? A F xY?0-W?FN?FTsin??0 W?FN??W?FTsin??2N

¡à×î´óĦ²ÁÁ¦Îª£º Fmax?fsFN?0.2?2?0.4N?Fmax?0.4N?Fs?0.66N¡àÎï¿éA²»Æ½ºâ¡£

4.4.2 ÖØP =100NµÄ³¤·½ÐξùÖÊľ¿é·ÅÖÃÔÚˮƽµØÃæÉÏ£¬³ß´çÈçͼËùʾ¡£Ä¾¿éÓëµØÃæ¼äµÄĦ²ÁϵÊý?s=0.4£¬Çóľ¿éÄܱ£³ÖƽºâʱµÄˮƽÁ¦FµÄ´óС¡££¨´ð°¸£ºF=31.25N£©

100 100 ½â£ºÓû±£³Öľ¿éƽºâ£¬±ØÐëÂú×ã 1£©²»»áÏòÓÒ»¬¶¯£¬B B A A F F 2£©²»»áÈÆDµã·­µ¹¡£

160 ȡľ¿éΪÑо¿¶ÔÏó 160 1) ľ¿é²»»áÏòÓÒ»¬¶¯:

P P ?F?FSD C X?0F?FS?0C D FS?FN?P?100N100 Y?0FN?P?0FN B A F Èôľ¿é²»»áÏòÓÒ»¬¶¯£¬ÔòÓ¦ÓУº y 160 F?FS?Fmax?fSFN?0.4?100?40N xP D C FS2) ľ¿é²»»áÈÆDµã·­µ¹: ȡľ¿éΪÑо¿¶ÔÏó Éèľ¿é´¦ÓÚÁÙ½ç״̬£¬ÊÜÁ¦Í¼ÈçͼËùʾ¡£ FN??ST??

?MD?0P?50?F?160?0?F?5P16?31.25N?F?31.25N

4.4.3 ¹ÄÂÖÀûÓÃ˫բ¿éÖÆ¶¯Æ÷ÖÆ¶¯£¬ÉèÔڸܸ˵ÄÄ©¶Ë×÷ÓÃÓдóСΪ200NµÄÁ¦F£¬·½ÏòÓë¸Ü¸Ë´¹Ö±£¬ÈçͼËùʾ¡£ÒÑÖªÕ¢¿éÓë¹ÄÂÖµÄĦ²ÁÒòÊýfs= 0.5£¬ÓÖ 2R=O1O2=KD=DC=O1A= KL= O2L= 0.5m£¬O1B=0.75 m£¬AC=O1D=1m£¬ED=0.25m£¬²»¼Æ×ÔÖØ£¬Çó×÷ÓÃÓÚ¹ÄÂÖÉϵÄÖÆ¶¯Á¦¾Ø¡£

19

ÀíÂÛÁ¦Ñ§B£¨1) Á·Ï°²á 32ѧʱ À¥Ã÷Àí¹¤´óѧ

רҵ ѧºÅ ÐÕÃû ÈÕÆÚ ³É¼¨

£¨´ð°¸£ºM=300N.m£©

½â£ºÈ¡BO1¸ËºÍAC¸ËΪÑо¿¶ÔÏó£» FCMO1?0O1A?FC?O1B?F?0 yO1B0.75?F?F??200?300NC O1A0.5x

È¡KE¸ËºÍEDC¸ËΪÑо¿¶ÔÏó£»

MD?0KD?FKsin??CD?F'C?0

?FK?F'Csin??300?KEED?3005N

È¡O2K¸ËºÍÕ¢¿éΪÑо¿¶ÔÏó²¢Éè³õʼ¹ÄÂÖ˳ʱÕëת¶¯

0.255mMO2?0KO2?FKcos??LO2?FN?0F'K K?

KO2FKcos?1?3005KD ?F??NF'CFKFSLO0.5EK2

1?30050.5LF??1200NNF\S0.50.255

O2F'N? OÈ¡¹ÄÂÖÑо¿¶ÔÏó£» MO?0RF'S?RF\S?0F\N ÐγÉÖÆ¶¯Á¦Å¼ ?F'S??F\SF'S

¡àÖÆ¶¯Á¦¾ØÎª£º Mf?2RF'S?2R?fSFN?300Nm

4.4.4 Ò»°ë¾¶ÎªR¡¢ÖØÎªP1µÄÂÖ¾²Ö¹ÔÚË®Æ½ÃæÉÏ£¬ÈçͼËùʾ¡£ÔÚÂÖÉϰ뾶ΪrµÄÖáÉϲøÓÐϸÉþ£¬´ËϸÉþ¿ç¹ý»¬ÂÖA£¬Ôڶ˲¿ÏµÒ»ÖØÎªP2µÄÎïÌå¡£ÉþµÄAB²¿·ÖÓëǦֱÏ߳ɦȽǡ£ÇóÂÖÓëË®Æ½Ãæ½Ó´¥µãC´¦µÄ¹ö¶¯Ä¦×èÁ¦Å¼M¡¢»¬¶¯Ä¦²ÁÁ¦FxºÍ·¨Ïò·´×÷ÓÃÁ¦Fy¡£

½â£ºÈ¡ÂÖΪÑо¿¶ÔÏó£»

P2sin??FS?0?FS?P2sin?X?0

yP2cos??P1?FN?0?FN?P1?P2cos?Y?0o

x MO?0?Mf?RFS?rP2?0 ???????FSMfFN

?Mf??RFS?rP2?P2(r?Rsin?)

20