圖示桁架結(jié)構(gòu)桿①的軸力為:()
A.-P/2 B.P C.3/2P D.2P
A.3P/4 B.P/2 C.0.707P D.1.414P
圖示三鉸拱結(jié)構(gòu)K截面彎矩為:()
A.3ql2/8 B.0 C.ql2/2 D.ql2/8