材料科学与工程导论双语课件教学课件 ppt 作者 陈克正 王玮 刘春延 等编Chapter 4.ppt

INTRODUCTIONTOMATERIALSSCIENCEANDENGINEERINGQingdaoUniversityofScience&——responsetomechanicalforces,strength,——icfields,conductivity,ization,————toabsorption,transmissionandscatteringoflight,refractionindex,——?Howdowedescribe“mechanicalbehavior”?Vocabulary:Stressandstrain,Hooke’slawClassesofbehavior::Stiffness,strength,ductility,toughness,hardnessGoal:(press,twist)orbreakasafunctionofappliedload,time,temperature,andotherconditions,weneedfirsttodiscussstandardtestmethodsformechanicalpropertiesofmaterials.•Tensilestress,s:•Shearstress,t:Stresshasunits:N/m2orlb/in2ENGINEERINGSTRESS•Tensilestrain:•Lateralstrain:•Shearstrain:Lisnegativewhenthesampleisintension,so•Simpletension:cable•Simpleshear:driveshaftNote:t=M/(•pression:pressivestructuremember(s<0here).()()MONSTRESSSTATES(1)