简介:Theplowofthesubmarineplowingtrencherisoneofthemainfunctionalmechanisms,anditsoptimizationisveryimportant.Thedesignparametersplayaverysignificantroleindeterminingtherequirementsofthetowingforceofavessel.Amulti-objectivegeneticalgorithmbasedonanalyticalmodelsoftheplowsurfacehasbeenexaminedandappliedineffortstoobtainoptimaldesignoftheplow.Foraspecificsoilcondition,thedraftforceandmoldboardsurfaceareawhicharethekeyparametersintheworkingprocessoftheplowareoptimizedbyfindingthecorrespondingoptimalvaluesoftheplowbladepenetrationangleandtwosurfaceanglesofthemaincuttingbladeoftheplow.Parameterssuchasthemoldboardsideangleofdeviation,moldboardliftangle,angularvariationofthetangentline,andthespanninglengtharealsoanalyzedwithrespecttotheforceofthemoldboardsurfacealongsoilflowdirection.Resultsshowthattheoptimizedplowhasanimprovedplowperformance.Thedraftforcesofthemaincuttingbladeandthemoldboardare10.6%and7%,respectively,lessthantheoriginaldesign.ThestandarddeviationofGaussiancurvatureofmoldboardisloweredby64.5%,whichimpliesthatthesmoothnessoftheoptimizedmoldboardsurfaceismuchgreaterthantheoriginal.
简介:文章阐明了PBL教学法在“船舶强度与结构设计”课程教学中的应用,介绍了其具体实施步骤。实施效果显示,该方法取得了良好的教学效果,具有一定的参考意义。