設(shè)直桿的軸向變形不計,圖示體系的動力自由度數(shù)為:()
A.2 B.3 C.4 D.5
A.3 B.4 C.5 D.6
A.質(zhì)量小,剛度小 B.質(zhì)量大,剛度大 C.質(zhì)量小,剛度大 D.質(zhì)量大,剛度小