項目13貨物加固技術任務2加固強度計算66課件

項目13貨物加固技術

Project13GoodsFasteningTechniques

任務2加固強度計算FasteningStrengthCalculation王曉明WangXiaoming對稱拉牽加固時，拉牽位置如下圖所示O——拉牽繩在貨物上的拴結點B——O點在車地板上的投影BC——O點所在縱向垂直平面至車輛邊線的距離A——拉牽繩在車輛上的拴結點知識點一常用加固方法的強度計算KnowledgePointIStrengthCalculationforCommonFasteningMethodsThepullingpositionoffasteningthroughsymmetricaltractionisshownasbelow.O--knotofthepullingropeonthecargo（1）采用拉牽加固時，每根拉牽繩應承受的力ForcebearedbyeachpullingropewhenthecargoisfastenedbytractionB--projectionofpointOonthewagonfloorBC--distancefromthelongitudinalverticalplanewherepointOislocatedtotheedgeofthewagonA--knotofthepullingropeonthewagon防止縱向移動時：防止橫向移動時：知識點一常用加固方法的強度計算preventinglateralmovement:當同一方向有n根拉牽繩時，每根應承受的拉力可按下式計算：preventinglongitudinalmovement:Whenthenumberofpullingropesinthesamedirectionisn,thepullingforcebornbyeachropecanbecalculatedaccordingtothefollowingformula:==防止縱向傾覆時：防止橫向傾覆時：preventinglateraloverturningpreventinglongitudinaloverturning==（KN）（KN）（KN）（KN）KnowledgePointIStrengthCalculationforCommonFasteningMethods(longitudinalmovement)(lateralmovement)(longitudinaloverturning)(lateraloverturning)(lateral)(longitudinal)知識點一常用加固方法的強度計算上式中l(wèi)縱——貨物縱向傾覆點至拉牽繩在貨物上拴結點所在橫向垂直平面間的距離，mm

l橫——貨物橫向傾覆點至拉牽繩在貨物上拴結點所在縱向平面間的距離，mmIntheaboveequation,l(longitudinal)isthedistancebetweenthelongitudinaloverturningpointofthecargoandthetransverseverticalplanewheretheropeknotislocatedonthegoods,mml(lateral)isthedistancebetweenthelateraloverturningpointofthecargoandthelongitudinalplanewhereofropeknotislocatedonthegoods,mmKnowledgePointIStrengthCalculationforCommonFasteningMethods知識點一常用加固方法的強度計算每根拉牽繩應承受的力：S≥max{S縱移，S橫移，S縱傾，S橫傾}選用鋼絲繩拉牽時，鋼絲繩的破斷拉力不得小于2S。選用鍍鋅鐵線或盤條拉牽時，每根拉牽繩需要股數(shù)為：（股）式中P許——一股鍍鋅鐵線或盤條的許用拉力，kNThepullingforcebornbyeachpullingrope:Thebreakingforceshallnotbelessthan2Swhenthewireisusedfortraction.Whenusinggalvanizedironwireorcoiledwirefortraction,thenumberofstrandsrequiredforeachpullingropeshallbeP(allowablepullingforce)isthepermissiblepullingforceofastrandofgalvanizedironwireorcoiledwire,kNKnowledgePointIStrengthCalculationforCommonFasteningMethods(longitudinalmovement)(lateralmovement)(longitudinaloverturning)(lateraloverturning)(allowablepullingforce)(strand)知識點一常用加固方法的強度計算注意事項Cautions使用鍍鋅鐵線、鋼絲繩捆綁加固貨物，應依據(jù)所加固貨物的拴結點情況，盡量考慮對稱拉牽Whenusinggalvanizedironwireorsteelwireropetofastengoods,consideringtheknottingstatusofthegoodsfastened,symmetricaltractionshouldbechosenasfaraspossible.彈性變形較大，抗拉能力較小的鍍鋅鐵線，不宜作為重量較大貨物捆綁加固用，一般當計算所需的單道拉牽鍍鋅鐵線在14股以上時，應改用鋼絲繩加固Galvanizedironwirewithlargeelasticdeformationandsmalltensilecapacityshouldnotbeusedforthefasteningofrelativelyheavygoods.Generally,whenthenumberofsinglepullinggalvanizedironwirerequiredismorethan14,thegoodsshouldbefastenedbythewireropeinreplacement.KnowledgePointIStrengthCalculationforCommonFasteningMethods知識點一常用加固方法的強度計算注意事項Cautions多股鍍鋅鐵線拉牽加固時，需用絞棍絞緊，絞棍應置于拉牽鐵線的中部，絞緊適度，不得過緊過松。絞棍留用時須固定；不留用時須采取措施防止鐵線回松Whenthemulti-strandedgalvanizedironwireisusedforfastening,itshouldbetightenedwithastrandedstick.Thestrandedstickshouldbeplacedinthemiddleofthepullingironwiretotightenthestrandappropriately,avoidingmakingittootightortooloose.Thestickshouldbefixedifitwillbeusedagain;whenitwillnotbeusedagain,measuresmustbetakentopreventthewirefrombecomingloose.拉牽繩與車底板的夾角一般應接近45°。若捆綁加固主要用于防止貨物水平移動時，拉牽繩與車底板的夾角可小于45°；若主要用于防止貨物傾覆，拉牽繩與車底板的夾角應適當大于45°Theanglebetweenthepullingropeandthewagonfloorshouldgenerallybecloseto45°.Ifthefasteningismainlyadoptedtopreventhorizontalmovement,theanglebetweenthepullingropeandthewagonfloorcanbelessthan45°;topreventgoodsoverturning,appropriatelygreaterthan45°,PointIStrengthcalculationforcommonfasteningmethods知識點一常用加固方法的強度計算注意事項Cautions多股小直徑鋼絲繩捆綁加固貨物時，兩端繩頭用鋼絲繩夾頭正反扣緊固定后，應用鐵質絞棍絞緊，在此種情況下，絞棍必須留用并予以固定Whenmultiple-strandedwireropeswithsmalldiameterareusedforfastening,afterthetwoendsoftheropearelockedandfixedwiththewireropechuck,theyshallbetightenedwithanironstrandedstick,inwhichcasethestickmustberetainedand