dw1?C1?2C2rlnr?C2r?2C3rdrr1dw1?C12?2C2lnr?C2?2C3 rdrrd2w1??C12?2C2lnr?3C2?2C3dr2rd2wudwMr??D(2?)drrdr1??D[?C1(1??)2?2C2(1??)lnr?C2(3??)?2C3(1??)]rdd2w1dwQr??D(2?)drdrrdr 4D??C2r在r=0处，w?0?C1?C4?0，于是
w?C2r2lnr?C3r2
在r=a处，wr?a?0(Mr)r?a?M0，即
?C2a2lna?C3a2?0 ???D[2C2(1??)lna?C2(3??)?2C3(1??)]?M0?C2??M0(3??)DC3?M0lna
(3??)Dw???薄板的内力
Qr?M0M0r2lnr?lnar2(3??)D(3??)D2M0raln(3??)Dr4M0
(3??)r
?2?1???r?Mr?M0?1?ln?3??a??
M0?r?M??1?3??21??ln????3???a???