已知簡(jiǎn)支梁受如圖所示荷載,則跨中點(diǎn)C截面上的彎矩為:()
A.0 B.(1/2)ql2 C.(1/4)ql2 D.(1/8)ql2
若梁的荷載及支承情況對(duì)稱(chēng)于梁的中央截面C,如圖所示,則下列結(jié)論中哪個(gè)是正確的()?
A.Q圖對(duì)稱(chēng),M圖對(duì)稱(chēng),且Qc=0 B.Q圖對(duì)稱(chēng),M圖反對(duì)稱(chēng),且Mc=0 C.Q圖反對(duì)稱(chēng),M圖對(duì)稱(chēng),且Qc=0 D.Q圖反對(duì)稱(chēng),M圖反對(duì)稱(chēng),且Mc=0
均質(zhì)圓盤(pán)作定軸轉(zhuǎn)動(dòng),其中圖a)、圖c)的轉(zhuǎn)動(dòng)角速度為常數(shù)(ω=C),而圖b)、圖d)的角速度不為常數(shù)(ω≠C),則下列哪個(gè)圖示的慣性力系簡(jiǎn)化的結(jié)果為平衡力系?()
A.圖A. B.圖B. C.圖C. D.圖D.