理论力学全套解疑07

??,vvzz,vvyy,vvxxCCCdddddd∫∫∫∫∫∫===,vvzz,vvyy,vvxxiiCiiCiiCddddddγγγγγγ∫∫∫∫∫∫===iγdviγ=γ=,vvzz,vvyy,vvxxCCCdddddd∫∫∫∫∫∫===7-2(a)7-2(b)7-21xkxmxxyySd)(d)(d221−=−=dS324320203214131ddddkamakamax)kxmx(x)kxmx(xSSxxaaC1−−=−−==∫∫∫∫mkx=ay=by=mxb=mabam=2kxy=2kab=2abk=mkxC=0.5ayC7-2cyxxyxxyyb0b0C)d-()d-(1212∫∫=kyx=2myx=1=⎟⎟⎠⎞⎜⎜⎝⎛−⎟⎟⎠⎞⎜⎜⎝⎛−=∫∫ymykyymykyyybbCdd000.4b7-3Oabcdef7-3OabgegfdbcS1S2S32x1y1x2y2x3y37-315,9,5403018111===×=yxS2322π3420,2132π34185.7810π415153125213118,5.1572115213323222=+==+======+==×=ryrxSyxSmm8.13mm5.13321332211321332211=++++==++++=SSSySySySySSSxSxSxSxCC7-47-47-4211=S200280=2800020032,2803211==yx3S2=π402=1600πx2=200y2=140=−−=212211SSSxSxxC184mm=−−=212211SSSySyyC132mm4