???????????????
???????????????
?????????????????????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
????????
???????????й?????????????г???????????????????????????????и?????????????12?????160??????????????????????????????????????е?豸???????????????и????????????????8-600mm???4.6m??????15m???????и??????????????????????????????????к?????????????????????豸?????????????????????????????????
???????????????
12*2200*9690
16*2200*7430
12*2200*9780
28*1750*5600
18*2000*8000
????12??25????????630??q345qd????????屨???????????
