英文弹性力学课件.ppt

文档介绍：,thestateofstressatapointwithreferencetothegeneralCartesianco-ordinatesystemisnotverysignificant. Becauseofthat: -ordinateaxes. Therefore,,txy,txzbestressesonplaneOBCLetsy,tyx,tyzbestressesonplaneOACLetsz,tzx,tzybestressesonplaneOABandsnx,sny,snzbestressesonplaneABC()wheredAistheareaofABCDividingEq.()bydA,():.26)()Eq.(),considerasetofaxesx',y',z'.Letx':坦腰俐淡祟然蘸籍据捌讥屋鹊磅熟复眨儿蔷扦留焚遏勿栈侗坊者某境指麦英文弹性力学课件英文弹性力学课件gthesedirectioncosines,()Substitutingforsnx,snyandsnzfromEq.()()Similarly,()or()and():sx=800kPa,sy=1200kPa,sz=-400kPa,txy=400kPa,tyz=-600kPaandtzx=(a)thestressesonaplanewhosenormalhasdirectioncosinesl1=1/4andl2=1/2,and(b):therelation:get:;fromEq.()::toaxesx’y’z’forstresses:ponentsandthedirectioncosinesa