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ԲľµÄ½ØÃæÃæ»ý¾Ø S =0.785¡Á50.00¡Á50.00 = 1962.50 N/mm2£»
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Ö§³Å¸Ö¹ÜµÄ×î´óÓ¦Á¦¼ÆËãÖµ 180.236 N/mm2 СÓÚ Ö§³Å¸Ö¹ÜµÄ¿¹Ñ¹Éè¼ÆÇ¿¶È 205.0 N/mm2, Âú×ãÒªÇó.
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°´¹æ·¶±í5.1.7,Ö±½Ç¡¢Ðýתµ¥¿Û¼þ³ÐÔØÁ¦È¡ÖµÎª8.00kN£¬°´ÕÕ¿Û¼þ¿¹»¬³ÐÔØÁ¦ÏµÊý0.80£¬¸Ã¹¤³Ìʵ¼ÊµÄÐýתµ¥¿Û¼þ³ÐÔØÁ¦È¡ÖµÎª6.40kN¡£
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ÆäÖÐ Rc -- ¿Û¼þ¿¹»¬³ÐÔØÁ¦Éè¼ÆÖµ,È¡6.40 kN£»
R -- ×ÝÏò»òºáÏòˮƽ¸Ë´«¸øÁ¢¸ËµÄÊúÏò×÷ÓÃÁ¦Éè¼ÆÖµ£» ¼ÆËãÖÐRÈ¡×î´óÖ§×ù·´Á¦£¬¸ù¾ÝÇ°Ãæ¼ÆËã½á¹ûµÃµ½ R=4.58 kN£» R < 6.40 kN , µ¥¿Û¼þ¿¹»¬³ÐÔØÁ¦µÄÉè¼Æ¼ÆËãÂú×ãÒªÇó.
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ÆäÖÐ N -- Á¢¸ËµÄÖáÐÄѹÁ¦Éè¼ÆÖµ£¬Ëü°üÀ¨£º ºá¸ËµÄ×î´óÖ§×ù·´Á¦£º N1 =4.578 kN £»
½ÅÊֹּܸܵÄ×ÔÖØ£º N2 = 1.2¡Á0.129¡Á4.500=0.697 kN£»
Â¥°åµÄ»ìÄýÍÁÄ£°åµÄ×ÔÖØ£º N3=1.2¡Á(1.00/2+(0.70-0.30)/2)¡Á1.00¡Á0.35=0.294 kN£»
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N4=1.2¡Á(1.00/2+(0.70-0.30)/2)¡Á1.00¡Á0.200¡Á(1.50+24.00)=4.284 kN£»
N =4.578+0.697+0.294+4.284=9.853 kN£»
¦Õ-- ÖáÐÄÊÜѹÁ¢¸ËµÄÎȶ¨ÏµÊý£¬Óɳ¤Ï¸±È lo/i ²é±íµÃµ½£»
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i -- ¼ÆËãÁ¢¸ËµÄ½ØÃæ»Ø×ª°ë¾¶ (cm)£ºi = 1.58£» A -- Á¢¸Ë¾»½ØÃæÃæ»ý (cm2)£º A = 4.89£» W -- Á¢¸Ë¾»½ØÃæµÖ¿¹¾Ø(cm3)£ºW = 5.08£» ¦Ò -- ¸Ö¹ÜÁ¢¸ËÖáÐÄÊÜѹӦÁ¦¼ÆËãÖµ ( N/mm2)£» [f] -- ¸Ö¹ÜÁ¢¸Ë¿¹Ñ¹Ç¿¶ÈÉè¼ÆÖµ£º[f] =205.00 N/mm2£» lo -- ¼ÆË㳤¶È (m)£»
Èç¹ûÍêÈ«²ÎÕÕ¡¶¿Û¼þʽ¹æ·¶¡·²»¿¼ÂǸßÖ§³Å¼Ü£¬°´ÏÂʽ¼ÆËã lo = k1uh (1) k1 -- ¼ÆË㳤¶È¸½¼ÓϵÊý£¬È¡ÖµÎª£º1.155 £»
u -- ¼ÆË㳤¶ÈϵÊý£¬²ÎÕÕ¡¶¿Û¼þʽ¹æ·¶¡·±í5.3.3£¬u =1.700£» ÉÏʽµÄ¼ÆËã½á¹û£º
Á¢¸Ë¼ÆË㳤¶È Lo = k1uh = 1.155¡Á1.700¡Á1.500 = 2.945 m£» Lo/i = 2945.250 / 15.800 = 186.000 £»
Óɳ¤Ï¸±È lo/i µÄ½á¹û²é±íµÃµ½ÖáÐÄÊÜѹÁ¢¸ËµÄÎȶ¨ÏµÊý¦Õ= 0.207 £» ¸Ö¹ÜÁ¢¸ËÊÜѹӦÁ¦¼ÆËãÖµ £»¦Ò=9853.140/(0.207¡Á489.000) = 97.341 N/mm2£» ¸Ö¹ÜÁ¢¸ËÎȶ¨ÐÔ¼ÆËã ¦Ò = 97.341 N/mm2 СÓÚ ¸Ö¹ÜÁ¢¸Ë¿¹Ñ¹Ç¿¶ÈµÄÉè¼ÆÖµ [f] = 205.00 N/mm2£¬ Âú×ãÒªÇó.
Èç¹û¿¼Âǵ½¸ßÖ§³Å¼ÜµÄ°²È«ÒòËØ£¬ÊÊÒËÓÉÏÂʽ¼ÆËã lo = k1k2(h+2a) (2)
k1 -- ¼ÆË㳤¶È¸½¼ÓϵÊý°´ÕÕ±í1ȡֵ1.167£»
k2 -- ¼ÆË㳤¶È¸½¼ÓϵÊý£¬h+2a = 2.700 °´ÕÕ±í2ȡֵ1.002 £» ÉÏʽµÄ¼ÆËã½á¹û£º
Á¢¸Ë¼ÆË㳤¶È Lo = k1k2(h+2a) = 1.167¡Á1.002¡Á(1.500+0.600¡Á2) = 3.157 m£»
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