??????????????????????
???????????????
?????????????????????λ????? kg ???????????????
W ???????? kg ?? = F ??????? mm2 ???? L ??????? m ??????????? g/cm3 ???? 1/1000
????????? 7.85g/cm3
??壨kg/m2??W= 7.85 ??d d= ??
??? 4mm ???壬???m2 ???????m2 ????=7.85 ??4=31.4kg
???????????????????
??????????????????????
3??1250??6000 32??
3??1800??7500 90??
4??1500??6000 32??
4??1500??8000 90??
4??1500??8000 90??
4??1800??8000 32??
5??1800??8000 21??
5??1800??8000 90??
6??1800??8000 35??
???3??21??????????12*1800*C????????????????????????
