F Fik 12 2i C F,k22 B 1.5 3(2i) 61 D 1.5 0.75 D 2 F11+F12+F1p=0. k F21+F2+F2p=0 (2a) k r)6 4 k1△1+k12△2+F1p=0 1.5 k1△1+k2△A,+F2p=0 2P (2 6 21 22 0 16 15 202 k1=107k21=1.57k2=-1.5k2 2216 16 52021/2/21 5 i l i 1.5 6 = 1.5i i l i 0.75 3 = 3(2i) 2i 4i 2 A B C D F12 F22 F11+F12+F1P =0………………(1a) F21+F22+F2P=0………………(2a) A B C D 1 F11 F21 i i 2i =1 k11 k21 =1 k12 k22 =0………..(1) =0………..(2) k111+ k122 +F1P k211+ k222 +F2P k21 i i 1.5 4 6 = 0 4i 6i k11 1.5i k12 k22 4 3 i 16 3i k11 =10i k21= -1.5i k12= -1.5i k i 16 15 22 =