简介:BasedonthecontinuityofthederivativesoftheNon-UniformRationalB-Splines(NURBS)curveandtheJaumannstrainmeasure,thepresentpaperadoptedthepositioncoordinatesofthecontrolpointsasthedegreesoffreedomanddevelopedaplanarrotation-freeEuler-Bernoullibeamelementforisogeometricanalysis,wherethederivativesofthefieldvariableswithrespecttothearc-lengthwereexpressedasthesumoftheweightedsumofthepositioncoordinatesofthecontrolpoints,andtheNURBSbasisfunctionswereusedastheweightfunctions.Furthermore,theconceptofbendingstripwasusedtoinvolvetherigidconnectionbetweenmultiplepatches.Severaltypicalexampleswithgeometricnonlinearitieswereusedtodemonstratetheaccuracyandeffectivenessoftheproposedalgorithm.Thepresentedformulationfullyaccountsforthegeometricnonlinearitiesandcanbeusedtostudythesnap-throughandsnap-backphenomenaofflexiblebeams.
简介:摘要:探究化学分析过程中,经常会运用的两种技术就是化学分析及仪器分析。这两种技术在分析过程中,具有发挥精准、合理且科学的特点,对分析化学有着重要影响。本文就分析化学中的化学分析和仪器分析的原理、差异性、统一性及关联性进行解析,并提出二者今后的发展方向和趋势。 关键词:分析化学;化学分析;仪器分析