中南大学材料力学--组合变形
答案
八年级地理上册填图题岩土工程勘察试题省略号的作用及举例应急救援安全知识车间5s试题及答案
组合变形答案
一、概念题
1.A;2.A;3.D;4.C;5.B;6.A;7.C;8.D;9.C;10.C
11.略
2216(8)1024PdQlT,,12. ,,,,,,133,d
二、计算题
1
截面形心和惯性矩计算:
zmm,59.521
zmm,40.482
64Imm,,4.8810z
1-1 截面上的内力:
MPyNm,,28857.6. FPkN,,12N
FMztN2,,,,,,26.8[]MPamaxtAIZ 安全 FMzcN1,,,,,32.3[]MPa,,maxcAIZ
2
设切口深度为x,则偏心距为:x/2
3F1210,P,,, t1Ax0.005(0.04),
x31210,,M2,,, t220.005(0.04),,xW
6
62,,,,,,,10010 得 xxxm,,,,12864000.00521tt12
h6,P4FMPPP2,3 ,,,,,,,,()()A2AWbhbhbh
A点的应力状态为单向压缩应力状态
,2PA ,,,,,,4545,2bh
1122PP ,,,,,,,,,()()454545,EEbhbh
Ebh,,,P 2(1),,
4 过O点横截面上的应力
h32,P420FMPPP2 ,,,,,,()()232AWddd,,,
M8PT ,,,2Wd,P
O点的应力状态为二向应力状态:
,,,,,,,,0xyy
,20Px ,,,a2EdE,
,,,,,,18Pxyxy,,,,,,cos90sin90,,xy2,4522d,
,,2P,,,,xyxy,,,,cos90sin90 ,,xy24522d,
14P,,,,()b2,,,,4545,EdE,5
a点的应力状态为二向应力状态:
FF43PP ,,,,,12.710FP2Ad,
16MM3eT,,,,,5.1010F P2Wd,P
,,,,,,xyxy3,,,,,cos60sin6013.910F,,xyP3022
,,,,,,xyxy3 ,,,,,,cos240sin2401.2410F,,xyP12022
11,35()(13.90.31.24)1014.3310F,,,,,,,,P,,,,93030120E20010,
FNMNm,,21072.107.Pe
采用第三强度理论校核强度
22,,,,,,,,,,,,434.33[]MPa 安全 r313
6
1) 计算外力
PmNm,,954920.46.n
163.68491.1FNFN,,PzPy FNFN,,,408.9293.75AyBy
252.3488.66FNFN,,,AzBz
2) 作计算简图
3) 作内力图
MNm,20.46.Tmax4) 危险截面为A截面: MNm,28.08.zmax
MNm,,21.28.ymax
5)危险点于A截面的边缘a点,a点的应力状态为二向应力状态:
2232MM,xymaxmax ,,,2.87MPa3d,
16MMeT,,,, 0.83MPa2Wd,P
,,,,,,xyxymax223.1MPa,,,,(),,min0.22xyMPa,22
,3.1MPa,1
,0MPa ,2
,,0.22MPa3,
,13,,,,1.66MPamax,2
6)采用第三强度理论校核强度
22,,,,,,,,,,,,43.32[]MPa 安全 r313