III II I I 00 I 0 I l 02 l 03 l 04 105 l 06 l 07 108 I 09 200 20 l 202 203 204 205 206 207 208 209
KIEM TOAN DAM CHU
3.3.5. M~t ciit ngang d§m thcp co xet d~n cat thep ban m~tcdu ;.
Ti~t di~n chju mo men am
Khoang each tu tr9ng tam m~t cdt t6i trµc trung hoa ban bl,lng:
- LAy 69 1
YLs,= LA = , mm (172)
Momen quan tinh m~t cdt d6i v6i trµc trung hoa cua m~t cdt:
Bang 17. D?c trung hinh hQc dAm thep c6 xet d~n c6t thep ban m~t cAu
M~t c~t Di~n Thong s6 Momen quan tfnh
ti ch cfiu ki~n B~ Chi~u A Ay Im I r()tig day (mm2 y ) (mm) (mm3) (mm4) (m:n;) (mm) (mm) Canh tren 360 30 10.800 550 5 .. 940.000 810.000 3.267.810.000 Ban b1,mg . 1.070 13 13.910 0 0 1.327.129.917 1.327.129.917 Canh du6i 410 32 13.120 -551 -7.229.120 1.119.573 3.984.364.693 CT tren 4.082 755 3.081.910 1.325.977 2.328.168.027 CT du6i 1.884 655 1.234.020 282.457 808.565.557 T6ng c()ng 43.796 3.026.810 11.716.038.194
Khoang each tu tn,ic trung hoa m?t dt tai mep tren <lAm thep:
Y~:S = 0, 5hw + t, - Y~s = 495, 9mm (174)
Khoang each tu tn,ic trung hoa m~t dt t6'i mep du6'i dAm thep:
(175)
M6men tlnh m?t dt d6i v6'i tn,ic di qua mep tren dAm thep:
r.
s'- =; _l!i_ = 23.204.515mm3
/,S 1- ·
Y1,s (176)
,:·,;
M6men finh m?t c~t d6i v6'i trvc di qua mep du6'i dftm thep:
r.
sh-= LS _l!i_ c- = 18.089.359mm3
Yu:;
{177)
Khoang each tu trvc trung hoa m?t dt t6'i c6t thep th& tren ban
m~tdu:
Momen tinh m?t dt d6i v6i tn,ic di qua c6t thep th6 tren ban m?t du: Sl'''.13 - = i;s = 16.776.563mm3 l.S ctt/3- · Y1.s (179)
Khoang each tu tn,ic trung hoa m?t c~t t6i c6t thep th6 du6i ban m?td.u:
Y~'.~·B- = 0, 5hw + t1 + t11 + 50--.,. y;8 = 5 85, 6mm (180)
Momen tTnh m?t c~t d6i v6i tn,ic di qua c6t thep.th6 tren ban m?t d.u:
sct~R- = J;S = 19.640.003mm3
J.S ctcR-
Y1.s