A combination of experimental measurements and numerical analysis was utilized to study the low-velocity impact damage of domestic carbon fiber-reinforced composites(CFRCs).The results indicated that the low-velocity ...A combination of experimental measurements and numerical analysis was utilized to study the low-velocity impact damage of domestic carbon fiber-reinforced composites(CFRCs).The results indicated that the low-velocity impact damage induced pits and longitudinal cracks on the front side,oblique cracks and delaminationin on the back side.The pit depth increased with the increasing impact energy.It was demonstrated that the numerical analysis strain history curve was similar to the experimentally measured strain history curve,which verified the accuracy of numerical analysis in which the Hashin failure criterion was used.The work provides basic data and theoretical basis for the promotion and application of the domestic carbon fiber,and demonstrates the feasibility of replacing imported carbon fibers with domestic carbon fibers.展开更多
Based on the active learning Kriging(ALK)model and the Hashin failure criterion,this paper proposes a new reliability evaluationmodel for composite stiffened panels,and conducts a reliability analysis on the ultimate ...Based on the active learning Kriging(ALK)model and the Hashin failure criterion,this paper proposes a new reliability evaluationmodel for composite stiffened panels,and conducts a reliability analysis on the ultimate bearing capacity.In addition,this paper studies the importance ranking of input variables.By comparing the calculation results of the reliability model proposed in this paper with those of the Monte Carlo method,the accuracy and efficiency of the ALK model are verified by case studies.Finally,the effects of longitudinal elastic modulus and fiber-direction tensile strength on post-buckling failure probability are discussed,which provides significant reference and guidance for the optimization and design of composite stiffened plates.展开更多
In this study,gradual and sudden reduction methods were combined to simulate a progressive failure in notched composite plates using a macro mechanics approach.Using the presented method,a progressive failure is simul...In this study,gradual and sudden reduction methods were combined to simulate a progressive failure in notched composite plates using a macro mechanics approach.Using the presented method,a progressive failure is simulated based on a linear softening law prior to a catastrophic failure,and thereafter,sudden reduction methods are employed for modeling a progressive failure.This combination method significantly reduces the computational cost and is also capable of simultaneously predicting the first and last ply failures(LPFs)in composite plates.The proposed method is intended to predict the first ply failure(FPF),LPF,and dominant failure modes of carbon/epoxy and glass/epoxy notched composite plates.In addition,the effects of mechanical properties and different stacking sequences on the propagation of damage in notched composite plates were studied.The results of the presented method were compared with experimental data previously reported in the literature.By comparing the numerical and experimental data,it is revealed that the proposed method can accurately simulate the failure propagation in notched composite plates at a low computational cost.展开更多
基金Funded by the Fundamental Research Funds for the Central Universities(No.2018IB001)and the National High-tech Research and Development Program of China(863 Program)(No.2013AA031306)。
文摘A combination of experimental measurements and numerical analysis was utilized to study the low-velocity impact damage of domestic carbon fiber-reinforced composites(CFRCs).The results indicated that the low-velocity impact damage induced pits and longitudinal cracks on the front side,oblique cracks and delaminationin on the back side.The pit depth increased with the increasing impact energy.It was demonstrated that the numerical analysis strain history curve was similar to the experimentally measured strain history curve,which verified the accuracy of numerical analysis in which the Hashin failure criterion was used.The work provides basic data and theoretical basis for the promotion and application of the domestic carbon fiber,and demonstrates the feasibility of replacing imported carbon fibers with domestic carbon fibers.
基金supported by government-sponsored research projects(MJZ3-2N21).
文摘Based on the active learning Kriging(ALK)model and the Hashin failure criterion,this paper proposes a new reliability evaluationmodel for composite stiffened panels,and conducts a reliability analysis on the ultimate bearing capacity.In addition,this paper studies the importance ranking of input variables.By comparing the calculation results of the reliability model proposed in this paper with those of the Monte Carlo method,the accuracy and efficiency of the ALK model are verified by case studies.Finally,the effects of longitudinal elastic modulus and fiber-direction tensile strength on post-buckling failure probability are discussed,which provides significant reference and guidance for the optimization and design of composite stiffened plates.
基金the financial support of Iran’s National Elites Foundation for this research under Grant number 15/19549.
文摘In this study,gradual and sudden reduction methods were combined to simulate a progressive failure in notched composite plates using a macro mechanics approach.Using the presented method,a progressive failure is simulated based on a linear softening law prior to a catastrophic failure,and thereafter,sudden reduction methods are employed for modeling a progressive failure.This combination method significantly reduces the computational cost and is also capable of simultaneously predicting the first and last ply failures(LPFs)in composite plates.The proposed method is intended to predict the first ply failure(FPF),LPF,and dominant failure modes of carbon/epoxy and glass/epoxy notched composite plates.In addition,the effects of mechanical properties and different stacking sequences on the propagation of damage in notched composite plates were studied.The results of the presented method were compared with experimental data previously reported in the literature.By comparing the numerical and experimental data,it is revealed that the proposed method can accurately simulate the failure propagation in notched composite plates at a low computational cost.
