项目13货物加固技术任务2加固强度计算66课件.pptxVIP

项目13货物加固技术

Project13GoodsFasteningTechniques

任务2加固强度计算FasteningStrengthCalculation王晓明WangXiaoming

对称拉牵加固时，拉牵位置如下图所示O——拉牵绳在货物上的拴结点B——O点在车地板上的投影BC——O点所在纵向垂直平面至车辆边线的距离A——拉牵绳在车辆上的拴结点知识点一常用加固方法的强度计算KnowledgePointIStrengthCalculationforCommonFasteningMethodsThepullingpositionoffasteningthroughsymmetricaltractionisshownasbelow.O--knotofthepullingropeonthecargo（1）采用拉牵加固时，每根拉牵绳应承受的力ForcebearedbyeachpullingropewhenthecargoisfastenedbytractionB--projectionofpointOonthewagonfloorBC--distancefromthelongitudinalverticalplanewherepointOislocatedtotheedgeofthewagonA--knotofthepullingropeonthewagon

防止纵向移动时：防止横向移动时：知识点一常用加固方法的强度计算preventinglateralmovement:当同一方向有n根拉牵绳时，每根应承受的拉力可按下式计算：preventinglongitudinalmovement:Whenthenumberofpullingropesinthesamedirectionisn,thepullingforcebornbyeachropecanbecalculatedaccordingtothefollowingformula:==防止纵向倾覆时：防止横向倾覆时：preventinglateraloverturningpreventinglongitudinaloverturning==（KN）（KN）（KN）（KN）KnowledgePointIStrengthCalculationforCommonFasteningMethods(longitudinalmovement)(lateralmovement)(longitudinaloverturning)(lateraloverturning)(lateral)(longitudinal)

知识点一常用加固方法的强度计算上式中l纵——货物纵向倾覆点至拉牵绳在货物上拴结点所在横向垂直平面间的距离，mml横——货物横向倾覆点至拉牵绳在货物上拴结点所在纵向平面间的距离，mmIntheaboveequation,l(longitudinal)isthedistancebetweenthelongitudinaloverturningpointofthecargoandthetransverseverticalplanewheretheropeknotislocatedonthegoods,mml(lateral)isthedistancebetweenthelateraloverturningpointofthecargoandthelongitudinalplanewhereofropeknotislocatedonthegoods,mmKnowledgePointIStrengthCalculationforCommonFasteningMethods

知识点一常用加固方法的强度计算每根拉牵绳应承受的力：S≥max{S纵移，S横移，S纵倾，S横倾}选用钢丝绳拉牵时，钢丝绳的破断拉力不得小于2S。选用镀锌铁线或盘条拉牵时，每根拉牵绳需要股数为：（股）式中P许——一股镀锌铁线或盘条的许用拉力，kNThepullingforcebornbyeachpullingrope:Thebreakingforceshallnotbelessthan2Swhenthewireisusedfortractio