大学《工程力学》课后习题解答汇总.doc

1-1试画出以下各题中圆柱或圆盘的受力图,与其它物体接触处的摩擦力均略去。FAOOOAAWWBBW(a)(b)(c)BOOWABWA(d)(e)解:FFOAFBBOOWAOFAWFABFBFAW(a)(b)(c)FBFBFAOWABOWAFA(d)(e)1-2试画出以下各题中AB杆的受力图。WWDBWBDB(b)(a)(c)《工程力学****题选解AFCACBWB(d)(e)解:FDFAAFDWWDBDBCFBFBWBFB(a)(b)(c)AFAFACFACBWFBBFB(d)(e)1-3试画出以下各题中AB梁的受力图。qABFCACBWABCDWD(a)(b)(c)ACBFqDFAWBA’D’B’(d)(e)1《工程力学****题选解解:qBFFAFBAACBABDWCFCFBWFCFD(a)(b)(c)qACBFFDAFBxFAWFBBFDFAFBy(d)(e)1-4试画出以下各题中指定物体的受力图。(a)拱ABCD;(b)半拱AB部分;(c)踏板AB;(d)杠杆AB;(e)方板ABCD;(f)节点B。FFAFBCBWDD’ADADB(a)(b)(c)(d)(e)(f)解:FFFBCABFAxAWDAFBDFDFAyFDFABFB(a)(b)(c)2《工程力学****题选解ACFAFAFABBDFCWBFBCBFBFBCW(d)(e)(f)1-5试画出以下各题中指定物体的受力图。(a)结点A,结点B;(b)圆柱A和B及整体;(c)半拱AB,半拱BC及整体;(d)杠杆AB,切刀CEF及整体;(e)秤杆AB,秤盘架BCD及整体。BAAPWBP(a)(b)AFDBFW1W2EFCACB(c)(d)AOBDGC’CW(e)解:(a)FATFABAFBTBFBAWFA3《工程力学****题选解(b)CF’PFBBAPBPFBPFN(c)FFFBxF’BxBBBFByF’ByW1W2W1W2AFAxFCxCAFCxFAxCFAyFCyFAyFCy(d)BFBEFFEFFCF’CEFCBFEFFFB(e)’CWFC’4《工程力学****题选解2-2杆AC、BC在C处铰接,另一端均与墙面铰接,如图所示,F1和F2作用在销钉C上,F1=445N,F2=535N,不计杆重,试求两杆所受的力。Ao30F143BCF2解:(1)取节点C为研究对象,画受力图,注意AC、BC都为二力杆,xF2(2)列平衡方程:4oF0FFsin60F0y1AC253oF0FFFcos600x1BCAC5F207NF164NACBCAC与BC两杆均受拉。2-3水平力F作用在刚架的B点,如图所示。如不计刚架重量,试求支座A和D处的约束力。2aBCaDA解:(1)取整体ABCD为研究对象,受力分析如图,画封闭的力三角形:FBFCADFDFAFAFD(2)由力三角形得5