材料力学第五版部分重点课后题答案材料力学第五版部分重点课后题答案涔犻涔犻涔犻涔犻2-2涓鎵撳叆鍩哄湴鍐呯殑鏈濡傚浘鎵绀猴紝鏉嗚酱鍗曚綅闀垮害鐨勬懇鎿姏 f=kx*2 锛岃瘯鍋氭湪妗殑鍚庡姏鍥俱?瑙細鐢遍鎰忓彲寰楋細 330233110,3/()3/(/)llNfdxFklFkFlFxFxldxFxl=鈭埆 1 鏈? 涔犻涔犻涔犻涔犻2-3 鐭崇爩妗鐨勫韬珮ml10=锛屽叾妯埅闈潰灏哄濡傚浘鎵绀恒傝嵎杞絢NF1000=锛屾潗鏂欑殑瀵嗗害 3/35.2mkg=蟻锛岃瘯姹傚韬簳閮 鎴潰涓婄殑鍘嬪簲鍔涖?瑙細澧韩搴曢潰鐨勮酱鍔涗负锛? gAlFGFN 蟻鈭掆垝=+鈭?)( 2-3 鍥?)(942.31048.935.210)114.323(10002kN 鈭?脳脳脳脳+脳鈭掆垝= 澧韩搴曢潰绉細)(14.9)114.323(22mA=脳+脳= 鍥犱负澧负杞村悜鍘嬬缉鏋勪欢锛屾墍浠叾搴曢潰涓婄殑姝簲鍔涘潎鍖鍒嗗竷銆?MPakPamkNAN34.071.33914.9942.31042 鈭掆増鈭?鈭?=蟽 涔犻涔犻涔犻涔犻2-7 鍥剧鍦嗛敟褰潌鍙楄酱鍚戞媺鍔涗綔鐢紝璇曟眰鏉嗙殑浼搁暱銆? 2-7 鍥?瑙細鍙栭暱搴负 dx 鎴浣擄紙寰厓浣擄級銆傚垯寰厓浣撶殑浼搁暱閲忎负锛? )()(xEAFdxld=鈭?锛屸埆鈭?=鈭唋lxAdxEFdxxEAFl00)()( lxrrrr=鈭掆垝 121 锛?2112112dxlddrxlrrr+鈭?+鈰呪垝=锛?2211222)(udxlddxA 鈰?铮凤铮讹，铮+鈭?蟺蟺锛宒xldddudxlddd2)22(12112 鈭?=+鈭?duddldx122 鈭?锛?()(22)(221212ududdlduuddlxAdx 鈭掆媴鈭?鈰呪垝=蟺蟺 鍥犳锛?)()(2)()(202100ududdEFlxAdxEFdxxEAFllll 鈭埆鈭垝鈭?=鈭喯 lldxlddddEFluddEFl011221021221)(21)(2 铮猴：铮猴：铮伙铮铮铮帮+鈭掆垝=铮猴；铮癸铮帮鈭?蟺蟺 铮猴：铮猴：铮伙铮铮铮帮鈭?鈭掆垝=21221)(2111221ddllddddEFl 蟺 铮猴；铮癸铮帮鈭掆垝=122122)(2ddddEFl 蟺 214dEdFl 蟺= 涔犻涔犻涔犻涔犻2-10 鍙楄酱鍚戞媺鍔汧浣滅敤鐨勭褰杽澹佹潌濡傚浘鎵绀恒傚凡鐭鏉愭枡鐨勫脊鎬 父鏁颁负谓,E 锛岃瘯姹侰涓嶥涓偣闂寸殑璺濈鏀瑰彉閲廋 D 鈭嗐?瑙細 EAFEAF 谓谓谓蔚蔚鈭?鈭?鈭?/ 寮忎腑锛屛次次碼 aaA4)()(22=鈭掆垝+=锛屾晠锛毼次轿礒 aF4鈭? 未谓蔚 EaFaa4鈭?=鈭嗭紝 未谓 EFaaa4鈭?鈭?鈭?未谓 EFaa4鈭?锛宎 aaCD12145)()(243232=+= 12145)()(243232aaaDC=+= 未谓未谓EFEFaaCDDCCD4003.1412145)(12145)(鈰呪垝=鈰呪垝=鈭?鈭?鈭?涔犻涔犻涔犻涔犻2-11 鍥剧缁撴瀯涓紝 AB 涓烘按骞虫斁缃殑鍒氭 潌锛屾潌 1 锛?锛?鏉愭枡鐩稿悓锛屽叾寮规 閲廏 PaE210=锛屽凡鐭l1=锛?21100mmAA=锛?3150mmA=锛宬NF20=銆傝瘯姹侰鐐圭殑姘村钩浣嶇 鍜岄搮鍨備綅绉汇? 2-11 鍥?瑙細锛?锛夋眰鍚勬潌鐨勮酱鍔? 浠B 鏉嗕负鐮旂瀵硅薄锛屽叾鍙楀姏鍥惧鍥炬墍绀恒? 鍥犱负 AB骞宠 锛屾墍浠? 0=鈭慩锛?45cos3=oN 锛?3=N 鐢卞绉版 彲鐭紝 0=鈭咰 H 锛?(10205.05.021kNFNN=脳= 锛?锛夋眰C 鐐圭殑姘村钩浣嶇 涓庨搮鍨備綅绉汇? A 鐐圭殑閾呭瀭浣嶇 锛歮 mmmmmNmmNEAlNl476.0100/21000010001000022111=脳脳=鈭? B 鐐圭殑閾呭瀭浣嶇 锛?mmmmmmNmmNEAlNl476.0100/21000010001000022222=脳脳=鈭?1 銆?銆?鏉嗙殑鍙樺舰鍗忥紙璋愶級璋冪殑鎯呭喌濡傚浘鎵绀恒傜敱1 銆?銆?鏉嗙殑鍙樺舰鍗忥紙璋愶級璋冩潯浠讹紝骞朵笖鑰冭檻鍒癆 B 涓哄垰鎬 潌锛屽彲浠緱鍒?C 鐐圭殑姘村钩浣嶇 锛?(476.045tan1mmloBHAHCH=鈰呪垎=鈭?鈭?鈭?C 鐐圭殑閾呭瀭浣嶇 锛?(476.01mmlC=鈭?鈭?涔犻涔犻涔犻涔犻2-12 鍥剧瀹炲績鍦嗘潌 AB 鍜孉 C 鍦鐐逛互閾扮浉杩炴帴锛屽湪 A 鐐逛綔鐢湁閾呭瀭鍚戜笅鐨勫姏 kNF35=銆傚凡鐭潌 AB 鍜孉 C 鐨勭洿寰勫垎鍒负 mmd121=鍜宮 md152=锛岄挗鐨勫脊鎬 閲忓彈鍔涘浘 鍙樺舰鍗忚皟鍥?GPaE210=銆傝瘯姹侫鐐瑰湪閾呭瀭鏂瑰悜鐨勪綅绉汇?瑙細锛?锛夋眰 AB 銆丄 C 鏉嗙殑杞村姏 浠妭鐐笰涓虹爺绌跺璞紝鍏跺彈鍔涘浘濡傚浘鎵绀恒? 鐢卞钩琛潯浠跺緱鍑猴細 0=鈭慩锛?45sin30sin=鈭抩ABoACNN ABACNN2=鈥?a) 0=鈭慪锛?3545cos30cos=鈭?oABoACNN 7023=+ABACNN 鈥?b) (a) (b)鑱旂珛瑙緱锛? kNNNAB117.181=锛沰 NNNAC621.252= 锛?锛夌敱鍙樺舰鑳藉師鐞嗘眰 A 鐐圭殑閾呭瀭鏂瑰悜鐨勪綅绉? 222211212221EAlNEAlNFA+=鈭? )(122221121EAlNEAlNFA+=鈭? 寮忎腑锛?(141445sin/10001mmlo=锛?(160030sin/8002mmlo= 2211131214.325.0mmA=脳脳=锛?221771514.325.0mmA=脳脳= 鏁咃細)(366.1)177210000160025621113210000141418117(35000122mmA=脳脳+脳脳=鈭?涔犻涔犻涔犻涔犻2-13 鍥剧 A 鍜孊涓偣涔嬮棿鍘熸湁姘村钩鏂瑰悜鐨勪竴鏍圭洿寰刴 md1=鐨勯挗涓濓紝鍦挗涓濈殑涓偣 C 鍔犱竴绔栧悜鑽疯浇 F 銆傚凡鐭挗涓濅骇鐢熺殑绾垮簲鍙樹负 0035.0=蔚锛屽叾鏉愭枡鐨勫脊鎬 閲廏 PaE210=锛?閽笣鐨勮嚜閲嶄笉璁傝瘯姹傦細 锛?锛夐挗涓濇 鎴潰涓婄殑搴斿姏锛堝亣璁鹃挗涓濈粡杩囧喎鎷夛紝鍦柇瑁傚墠鍙涓虹鍚堣儭鍏嬪畾寰嬶級锛?锛?锛夐挗涓濆湪 C 鐐逛笅闄嶇殑璺濈鈭嗭紱 锛?锛夎嵎杞紽鐨勫笺?瑙細锛?锛夋眰閽笣妯埅闈笂鐨勫簲鍔? )(7350035.0210000MPaE=脳=蔚蟽 锛?锛夋眰閽笣鍦鐐逛笅闄嶇殑璺濈鈭? )(72100002000735mmElEANll=脳=鈰?=鈭喯冦傚叾涓紝 AC 鍜孊 C鍚刴 m5.3 銆? 996512207.05.10031000cos=伪 o7867339.4)5.10031000arccos(=伪 )(7.837867339.4tan1000mmo=鈭?锛?锛夋眰鑽疯浇 F 鐨勫? 浠缁撶偣涓虹爺绌跺璞紝鐢卞叾骞崇琛潯浠跺彲寰楋細 0=鈭慪锛?sin2=鈭扨 aN 伪蟽 sin2sin2AaNP= )(239.96787.4sin114.325.0735202N=脳脳脳脳脳= 涔犻涔犻涔犻涔犻2-15姘村钩鍒氭 潌 AB 鐢变笁鏍笲 C,BD 鍜孍 D 鏀拺锛屽鍥撅紝鍦潌鐨凙绔壙鍙楅搮鍨傝嵎杞紽=20KN,涓夋牴閽潌鐨勬 鎴潰绉垎鍒负 A1=12 骞虫柟姣背锛孉 2=6骞虫柟姣背锛孉,3=9 骞虫柟姣背锛屾潌鐨勫脊鎬 閲廍=210Gpa 锛屾眰锛?锛?锛?绔偣 A 鐨勬按骞冲拰閾呭瀭浣嶇 銆?锛?锛?搴旂敤鍔熻兘鍘熺悊姹傜鐐笰鐨勯搮鍨備綅绉汇?瑙細锛?锛?30323311031231111711961222,3/()3/(/)cos450sin4500.450.15060,401,0,60100.153.87210101210401llNNNNNNNfdxFklFkFlFxFxldxFxlFFFFFFFFKNFKNFKNFllEAFllEA 鈭?=铮?铮粹垝+鈭?=铮诧鈭捗?脳=铮斥埓=鈭?鈭?鈭捗椕椻垎=脳脳脳脳鈭?=鈭埆顎顎1 鏈?鐢辫儭鍏嬪畾鐞嗭紝796x2y2100.154.762101012104.762320.23AlAll 鈭捗?脳脳脳鈭?鈭?鈭?鈭喢?鈭喢?鈫撲粠鑰屽緱锛岋紝锛堬級 锛?锛?y1122y+020.33VFAFlFlA 蔚=脳鈭嗏垝脳鈭喢椻垎=鈭?鈫擄紙锛? 涔犻涔犻涔犻涔犻2-17 绠鍗曟鏋跺強鍏跺彈鍔涘鍥炬墍绀猴紝姘村钩鏉咮 C 鐨勯暱搴淇濇寔涓嶅彉锛屾枩鏉咥 B鐨勯暱搴彲闅忓瑙捨哥殑鍙樺寲鑰屾敼鍙樸備袱鏉嗙敱鍚屼竴绉嶆潗鏂欏埗閫狅紝涓旀潗鏂欑殑璁哥敤鎷夊簲鍔涘拰璁哥敤鍘嬪簲鍔涚浉绛夈傝姹備袱鏉嗗唴鐨勫簲鍔涘悓鏃惰揪鍒拌鐢簲鍔涳紝涓旂粨鏋勭殑鎬婚噸閲忎负鏈灏忔椂锛岃瘯姹傦細 锛?锛変袱鏉嗙殑澶硅锛?锛?锛変袱鏉嗘 鎴潰闈 鐨勬瘮鍊笺?瑙細锛?锛夋眰杞村姏 鍙栬妭鐐笲涓虹爺绌跺璞紝鐢卞叾骞宠 鏉欢寰楋細 鈭?0Y 0sin=鈭扚 NAB 胃 胃sinFNAB= 鈭?0X 0cos=鈭掆垝 BCABNN 胃 胃胃胃胃 cotcossincosFFNNABBC=鈰?鈭? 2-17 锛?锛夋眰宸綔搴斿姏 胃蟽 sinABABABABAFAN= BCBCBCBCAFAN 胃蟽 cot= 锛?锛夋眰鏉嗙郴鐨勬婚噸閲? )(BCBCABABlAlAVW+=鈰?纬纬 銆偽虫槸閲嶅姏瀵嗗害锛堢畝绉伴噸搴紝鍗曚綅锛?/mkN 锛夈?)cos(lAlABCAB+=胃纬 )cos1(BCABAAl+鈰?胃纬 锛?锛変唬鍏璁炬潯浠舵眰涓潌鐨勫瑙? 鏉欢鈶狅細 sin 蟽胃蟽=ABABABABAFAN 锛屛赶僺 inFAAB= cot 蟽胃蟽=BCBCBCBCAFAN 锛? cot 蟽胃 FABC= 鏉欢鈶碉細W 鐨勬婚噸閲忎负鏈灏忋? )cos1(BCABAAlW+鈰?胃纬)cos1(BCABAAl+鈰?胃纬 )cotcos1sin(蟽胃胃胃蟽纬 FFl+鈰呪媴=)sincoscossin1(胃胃胃胃蟽纬+=Fl 铮凤铮革铮，铮