简介:直升机在飞行降落时尾桨操纵连杆发生断裂,对断裂的尾桨连杆组件损伤及磨损情况进行外观检查,宏微观观察分析连杆断口,并对连杆的材料成分、金相组织和硬度进行检查。结果表明:连杆的断裂性质为疲劳断裂,疲劳起源于螺纹根部,疲劳区占断口总面积80%以上;连杆端部的球轴承产生了异常的磨损。分析认为:由于连杆端的球轴承产生了异常的磨损,导致其对连杆的限位功能不良,连杆发生轻微偏转使连杆上形成了附加的弯曲应力。该应力与连杆上的工作应力叠加,造成连杆发生了疲劳断裂。此外,对连杆硬度的检测表明连杆的硬度仅为HRC22.7,说明其强度较低,疲劳抗力较差,也是连杆容易发生疲劳断裂的原因。
简介:Characteristicvaluesandtestingmethodsfordeepdrawingprocesses;Comparisonofexperimentalandsimulateresultsforamildsteelandadual-phasesteeldeformedundertensionanddeep-drawing;Computer-aidedprocessdesignsystemforaxisymmetricdeepdrawing;Contactlesson-linemeasurementofmaterialflowforclosedloopcontrolofdeepdrawing;Deepdrawingofnickelfoilandstainlesssteelfoil;
简介:Adatabaseorientedprocesscontroldesignalgorithmforimprovingdeep-drawingperformance,Afiniteelementandexperimentalstudyofsheetdeformationasinfluencedbydrawbeadendgeometry,Anoteondeepdrawingprocess:numericalsimulationandexperimentalvalidation,Anovelrolling-annealingcycleforenhanceddeepdrawingpropertiesinIFsteels,Anoveltechniqueoffrictionaideddeepdrawingusingablank-holderdividedintofoursegments.
简介:Drivesystemoptimizationofhydraulicdeepdrawingpressesfordevelopmentandcommissioning;Economicallaser-cutblanksfordeepdrawing;Effectofanisotropyandprebulgingonhydromechanica!deepdrawingofmildsteelcups;EnhancetheFormabilityofSheetMetalviaSmartTooling;Experimentalandnumericalapproachesofspringbackofhigh-performancesteelsdrawnwithu-shapedtoolsandanindustrialsidemembertool
简介:Afundamentalstudyofcanformingbythestretch-drawingprocess;Anexerciseincoldironingasthepost-forgingoperationfornet-shapemanufacture;Designofhorizontalmechanicalpressesfordeepdrawingandironingprocess;DevelopmentofsimulationcodeforcalculatingresidualstressdistributioninD-Icansproducedbyboth-sidedironingprocess;Fractureanalysisoftubedrawingwithamandrel;Improvementoffillingratioandreductionofformingpressure-atrialforformingofaspurgearmadefromthedrawncupⅡ
简介:铜拉链的拉头加工工艺,在冲裁、弯形和对折弯形后整形。使处于2.7±0.05mm空间中的倒U字形条,整形成2.60-0.15×4.3mm×63°10'的V字形条。整形后V字形条要与拉头外形的中心线对称,由于拉链的产量大,价格便宜,故铜拉头冲压整形是关键性的工序。而要从两边仅为0.05㎜的单边间隙中,将倒U字形条整形成V字形条。可采用支承块支撑拉头,压板是依靠橡皮弹力轻压拉头,并需要进行完全定位。然后,在左右斜块作用下,使安装在左右滑块上左右挤板产生挤压,将U字形条整形成V字形条。这种整形成形效果不仅使成形的效率高,而且是整形成形的对称性好,整形的质量高、价格便宜。