第十二章彎曲的幾個(gè)補(bǔ)充問(wèn)題02

1、 FyFzFzFj jFyFzyxz撓曲線撓曲線梁的軸線梁的軸線對(duì)稱(chēng)軸對(duì)稱(chēng)軸垂直縱向?qū)ΨQ(chēng)面垂直縱向?qū)ΨQ(chēng)面xyz梁的軸線梁的軸線對(duì)稱(chēng)軸對(duì)稱(chēng)軸水平縱向?qū)ΨQ(chēng)面水平縱向?qū)ΨQ(chēng)面撓曲線撓曲線FyFzmmzyMyxMz yyMzI zzMyI yzyzMMzyII mmzyMyxMz e ( z0 ,y0 )000yzeyzMMzyII yzyzMMzyIIzyxzOe (z0,y0)000yzyzMMzyII中性軸中性軸000yzyzMMzyII00tancotyyzyzzIIMzyMIIjj 22zyMMM tantanzzzzyyyywFIIwFIIjjyzOwj j中性軸中性軸22zywww 討討

2、論：論：中性軸D2D1OD1D2zy中性軸中性軸中性軸中性軸D2D1max xA B CzyF2=2kNF1=1kN 0.5m 0.5m 4080zyO xA B CzyF2=2kNF1=1kN 0.5m 0.5m xA B CzyF2=2kNF1=1kN 0.5m 0.5m 1kNmMz(x)圖圖1kNmMy(x)圖圖zyxMyzyxzzyx拉拉拉拉壓壓D2D18040zyyyyWM max zzzWM max 2408061 yW2804061 zW22408061mkN1804061mkN1 yyzzWMWMMPa02. 7)max(1 yyzzDWMWM MPa02. 7)max(2

3、D zyxMyzyxz拉拉拉拉壓壓41101101128040124080tan3333 yzzyMMII 14 zy中性軸中性軸 8040zy中性軸中性軸 1+-拉拉壓壓40Fqaayzz40FqaayFyFzqaFFqaFFzy321. 040sin383. 040cos FzACBxz面面qFyACBxy面面DD0.617abcda0.456qa20.266qa20.383qa2Mz圖圖ac0.321qa20.642qa20.444qa2My圖圖3636m105 .31m10237 yzWWqWMWMyyAzzAA3max105 .21)( qWMWMyyDzzDD3max1002.16

4、)( .)(maxmax qWMWMyyAzzAA3 310105 52121kN/m44. 75 .21101603 q AAAq(x)F1F2tyOmtyzdhbh1hbdy1y1dISFzz*S )4(22221SyhdhbdIFz tyOmtyzdhbh1hbdy1y1q(x)mmnnxdxFSMFSM+dMnmmndxxnmnmdxmnOzydxm2hDCA111dAADmCdxBF*1NF*11NIhMz21 IhMMz2d11 z*AA*IhMAAAF2dd1*1*11N hIMMFz*2N2d A*mnOzydxm2hDCAADmCdxB111dAF*1NF*11NA*FF*2N*1N ADmCdxBF*1NF*11NSdF 1 1xFdd1S 0d*2NS*1N FFF z*IhMF21N hIMMFz*2N2dzIhF2S1 ADmCdxBF*1NF*11NSdF 1 1 11zIhF2S1 mnOzydxm2hDCA 1 1mmb max1zIhF2S1 zIbhF2Smax1 yOmyzdhbh1hbdy1y1)4(22221SyhdhbdIFz 11()2R2ddhhFAdy* *A A)()4(2222221SdyyhdhbIFhhz yOmyzdhbh1hbdy1y1 1 1mmb m