文档介绍：该【土木工程 外文翻译 外文文献 英文翻译 】是由【1781111****】上传分享，文档一共【5】页，该文档可以免费在线阅读，需要了解更多关于【土木工程 外文翻译 外文文献 英文翻译 】的内容，可以使用淘豆网的站内搜索功能，选择自己适合的文档，以下文字是截取该文章内的部分文字，如需要获得完整电子版，请下载此文档到您的设备，方便您编辑和打印。:..Howlargemustapartbetowithstandagivensetofloadswhathesizeandmaterialforapart?,theconditionswhichlimitload-,wewouldnotbeveryhappywiththem;theywouldbetoospringy’.,weshouldbeconcernedwiththemaximum‘deflection’thatwe,asindividuals,,,thesamepeoplemaygivedifferentanswersdependingonwhethertheyarepayingforthefloorornot!:..youwillseelargedeflections;,youknowthattheimportantissueisthatofstructuralintegrity’,,,;whoknowswhatthe‘worst’conditionsmightbe?Engineerswhoareresponsibleforthedesignofairplanewingstructuresmustknow,withsomedegreeofcertainty,whatthe‘worst’‘worst’—onceevery1000hours,oronceevery10000hours,,,however,thataparthasfailedinservice,andweareasked;Why?‘Error’efromthreedistinctlydifferentsources,anyorallofwhichcancausefailure::..havebeenabittoooptimistic:Maybeweignoredsomeloads;maybeourequationsdidnotapplyorwerenotproperlyapplied;maybeweoverestimatedtheintelligenceoftheuser;:Whenadeviceinvolvesheavilystressedmembers,theeffectivestrengthofthememberscanbegreatlyreducedthroughimpropermanufactureandassembly:Maythewrongmaterialwasused;maybetheheattreatmentwasnotasspecified;maybethesurfacefinishwasnotasgoodascalledfor;mayapartwasoutoftolerance’;maybesurfacewasdamagedduringmachining;maybethethreadswerenotlubricatedatassembly;:Asweallknow,wecandamagealmostanythingifwetryhardenough,identally:Wewenttoofast;welostcontrol;wefellasleep;wewerenotwatchingthegages;thepowerwentoff;putercrashed;hewastakingacoffeebreak;ottoturnthemachineoff;youfailedtolubricateit,:Nothingisdesignedperfectly;nothingismadeperfectly;:..ur,hecause,wecanhedesign;hefailedpartsformanufacturingdeficiencies;butwecannotusuallydeterminehowthedevicewasused(ormisused).Inseriouscases,thiscangiverisetoconsiderabledifferencesofopinion,,,thesafetyfactor(SF),orbydesigningtostresslevelsbelowthosethatthematerialactuallycanwithstand(frequentlycalleddesignstresses’).Safetyfactor=SF=failureload/designload=failurestress/,weshoulduselargervalueswhen::..(asinaircraftandspacecraft),,,test,manufacture,anduse,’.Thisisnottoimplythatengineersareignorant,buttohelpinstillinthemhumility,caution,,.