項(xiàng)目13貨物加固技術(shù)

Project13GoodsFasteningTechniques

任務(wù)2加固強(qiáng)度計(jì)算FasteningStrengthCalculation王曉明WangXiaoming對(duì)稱拉牽加固時(shí)，拉牽位置如下圖所示O——拉牽繩在貨物上的拴結(jié)點(diǎn)B——O點(diǎn)在車地板上的投影BC——O點(diǎn)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(jié)點(diǎn)知識(shí)點(diǎn)一常用加固方法的強(qiáng)度計(jì)算KnowledgePointIStrengthCalculationforCommonFasteningMethodsThepullingpositionoffasteningthroughsymmetricaltractionisshownasbelow.O--knotofthepullingropeonthecargo（1）采用拉牽加固時(shí)，每根拉牽繩應(yīng)承受的力ForcebearedbyeachpullingropewhenthecargoisfastenedbytractionB--projectionofpointOonthewagonfloorBC--distancefromthelongitudinalverticalplanewherepointOislocatedtotheedgeofthewagonA--knotofthepullingropeonthewagon防止縱向移動(dòng)時(shí)：防止橫向移動(dòng)時(shí)：知識(shí)點(diǎn)一常用加固方法的強(qiáng)度計(jì)算preventinglateralmovement:當(dāng)同一方向有n根拉牽繩時(shí)，每根應(yīng)承受的拉力可按下式計(jì)算：preventinglongitudinalmovement:Whenthenumberofpullingropesinthesamedirectionisn,thepullingforcebornbyeachropecanbecalculatedaccordingtothefollowingformula:==防止縱向傾覆時(shí)：防止橫向傾覆時(shí)：preventinglateraloverturningpreventinglongitudinaloverturning==（KN）（KN）（KN）（KN）KnowledgePointIStrengthCalculationforCommonFasteningMethods(longitudinalmovement)(lateralmovement)(longitudinaloverturning)(lateraloverturning)(lateral)(longitudinal)知識(shí)點(diǎn)一常用加固方法的強(qiáng)度計(jì)算上式中l(wèi)縱——貨物縱向傾覆點(diǎn)至拉牽繩在貨物上拴結(jié)點(diǎn)所在橫向垂直平面間的距離，mm

l橫——貨物橫向傾覆點(diǎn)至拉牽繩在貨物上拴結(jié)點(diǎn)所在縱向平面間的距離，mmIntheaboveequation,l(longitudinal)isthedistancebetweenthelongitudinaloverturningpointofthecargoandthetransverseverticalplanewheretheropeknotislocatedonthegoods,mml(lateral)isthedistancebetweenthelateraloverturningpointofthecargoandthelongitudinalplanewhereofropeknotislocatedonthegoods,mmKnowledgePointIStrengthCalculationforCommonFasteningMethods知識(shí)點(diǎn)一常用加固方法的強(qiáng)度計(jì)算每根拉牽繩應(yīng)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(shí)，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(shí)，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(shí)點(diǎn)一常用加固方法的強(qiáng)度計(jì)算注意事項(xiàng)Cautions使用鍍鋅鐵線、鋼絲繩捆綁加固貨物，應(yīng)依據(jù)所加固貨物的拴結(jié)點(diǎn)情況，盡量考慮對(duì)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(dāng)計(jì)算所需的單道拉牽鍍鋅鐵線在14股以上時(shí)，應(yīng)改用鋼絲繩加固Galvanizedironwirewithlargeelasticdeformationandsmalltensilecapacityshouldnotbeusedforthefasteningofrelativelyheavygoods.Generally,whenthenumberofsinglepullinggalvanizedironwirerequiredismorethan14,thegoodsshouldbefastenedbythewireropeinreplacement.KnowledgePointIStrengthCalculationforCommonFasteningMethods知識(shí)點(diǎn)一常用加固方法的強(qiáng)度計(jì)算注意事項(xiàng)Cautions多股鍍鋅鐵線拉牽加固時(shí)，需用絞棍絞緊，絞棍應(yīng)置于拉牽鐵線的中部，絞緊適度，不得過(guò)緊過(guò)松。絞棍留用時(shí)須固定；不留用時(shí)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(yīng)接近45°。若捆綁加固主要用于防止貨物水平移動(dòng)時(shí)，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(yīng)適當(dāng)大于45°Theanglebetweenthepullingropeandthewagonfloorshouldgenerallybecloseto45°.Ifthefasteningismainlyadoptedtopreventhorizontalmovement,theanglebetweenthepullingropeandthewagonfloorcanbelessthan45°;topreventgoodsoverturning,appropriatelygreaterthan45°,PointIStrengthcalculationforcommonfasteningmethods知識(shí)點(diǎn)一常用加固方法的強(qiáng)度計(jì)算注意事項(xiàng)Cautions多股小直徑鋼絲繩捆綁加固貨物時(shí)，兩端繩頭用鋼絲繩夾頭正反扣緊固定后，應(yīng)用鐵質(zhì)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