简介:Webuiltathree-dimensionalmodeltosimulatethedisturbanceofthestressfieldnearthereversefaultinZhaziao,LeyiTownshipowingtohydraulicfracturing.Theporepressure,andshearandnormalstressesduringfracturingareanalyzedindetail.Inputrockmechanicsparametersaretakenfromlaboratorytestdataofshalesamplesfromthestudyarea.Thesimulationresultssuggestthatafter16hoursoffluidinjection,thepore-pressurevariationcanactivatethereversefault,i.e.,weobservereverseslip,andtheshearstressanddisplacementonthefaultplaneincreasewithtime.Thebiggeststress–strainchangeoccursafteronehouroffluidinjectionandtheyieldpointappearsabout0.5hafterinjection.Toobservethestressevolutionineachsection,thenormaldisplacementontheboundaryisconstrainedandthefaultplaneissetasnonpermeable.Thus,theslidingislimitedandthesheardisplacementisonlyinthescaleofmillimeters,andthecalculatedmagnitudeoftheinducedearthquakesisbetweenMw-3.5andMw-0.2.Thesimulationresultssuggestthatfluidwaterinjectionresultsininhomogeneousfracturing.Themainrupturedareasarearoundtheinjectionpositions,whereastheextentofrupturingandcracksinotherareasarerelativelysmall.Nevertheless,nonnegligiblefaultactivationisrecorded.Sensitivityanalysisofthekeyparameterssuggeststhattheporepressureismostsensitivetothemaximumunbalancedforceandtheinternalfrictionanglestronglyaffectsthefaultslip.Finally,thecomparisonbetweentheeffectivenormalstressandthemaximumandminimumprincipalstressesonthefaultplaneexplainsthefaultinstability,i.e.,theMohrcirclemovestowardstheleftwithdecreasingradiusreducesandintersectsthecriticalslipenvelope,andcausesthefaulttoslip.
简介:摘要焊接残余应力的复杂性导致难以通过试验、检测等手段获得残余应力分布规律,精度难以保证。在计算机高速发展的今天,大多采用数值模拟方法。因此结合存在的实际问题,以箱体结构为研究对象,利用Simufactwelding专用焊接软件优化工艺设计,提出合理的施焊方案,控制残余应力以满足结构的使用要求。
简介:摘要明确焊接顺序对T形接头焊接残余应力场的影响对于保证焊接质量以及焊件的加工效率具有重要意义。本文主要探讨了焊接顺序对T形接头焊接残余应力场的影响,在具体分析中主要从分段焊、多道焊、多层焊对T形接头焊接残余应力场的影响等方面进行分析。
简介:摘要:多数矿床的成矿作用与一定的构造因素有关,形成并存在于地壳中的各种矿产,明显地受到地质构造的控制。云龙锡矿带是我国西南地区重要的成矿区带,但地质研究程度确较为薄弱。本文对云龙锡矿带南、北两侧的构造应力场进行详细研究,认为约30km云龙锡矿带成矿期构造应力成为剪切应力,区内最主要的控矿构造应为压扭性构造,结合里德尔(Riedel shear)共轭剪切破裂模式,该类剪切模式在走向和倾向上会有比较稳定的延伸,因此可以认为,区内重要矿山外围和深部找矿会有比较大的潜力。