12423

1022 دكتري

دكتري

طراحي كاربردي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1395

ده، [139]ص.: مصور، جدول، نمودار

ص. ع. به فارسي و انگليسي

محمدرضا فروزان

محمد مشايخي

مجتبي محزون، بيژن برومند، محمد حيدري، عليرضا شهيدي

1396/02/24

كتابنامه

مكانيك

مهندسي مكانيك

ID1022 دكتري

Developing an anisotropic damage model and using it for impact modeling of composite beams Elham Shahabi Ghahfarokhi e shahabi@me iut ac ir Date of Submission 04 09 2017 Department of mechanical engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree Ph D Language FarsiSupervisor Mohammad Reza Forouzan Email address forouzan@cc iut ac irAbstract Damage in polymer matrix composite materials has been formulated in this thesis The number of modelparameters in this formulation has been reduced to the minimum possible one to decrease the number ofexpensive experimental tests required for setting parameters To this aim tensor formulation has been utilized because the independence of the tensor formulation from the selection of the coordinate system reduces thenumber of model parameters Furthermore the damage evolution rule has been formulated usingthermodynamics of irreversible processes which reduce the number of model parameters needs for setting thedamage evolution rule Using thermodynamically consistent evolution rule requires that the damage surface hasbeen formulated based on the damage energy release rate DERR and stress components Accordingly a noveldamage surface with tensor characteristics has been proposed This new failure criterion has been compared withboth the Tsai Wu and experimental data for a number of composite materials After the initial assessment of thecriterion it has been used as the damage surface in a damage mechanics formulation using thermodynamicallyconsistent evolution rule The model has been developed for the general elastic plastic damage state For thepresent material however the plastic deformation in glass polyester pultruded composite beams has beenneglected and the formulation has been reduced to the elastic damage state This model has been firstly verifiedfor an individual element under three basic loadings i e tensile compressive and simple shear loadings Thenthe model has been used for predicting the damage caused by low velocity impact loadings The simulationresults predict the damaged region and force time curve of the impact event in relatively good agreement withthe experimental results KeywordsContinuum damage mechanics CDM thermodynamics of irreversible processes lowvelocity impact

محمدرضا فروزان

محمد مشايخي

مجتبي محزون، بيژن برومند، محمد حيدري، عليرضا شهيدي