As composites are increasingly used in aircraft,composites-based the primary-load bearing structures were gradually considered for wide application. However,to determine worst case of the primary-load bearing structur...As composites are increasingly used in aircraft,composites-based the primary-load bearing structures were gradually considered for wide application. However,to determine worst case of the primary-load bearing structures of composites is quite necessary. In this paper,to reveal the effects on the mechanical performance of composite laminate plates were made,respectively by open holes and different environments. Firstly,we obtained the benchmark of composite plates by conducting tension and compression of room temperature and dry air( RTD),tension of cold temperature and dry air( CTD),and compression of elevated temperature and wet( ETW). Then opened circle holes were introduced into composite plates to know the influence of holes. Finally,CTD and ETW environment were respectively investigated to composite plate with holes being under tension and compression loads. As shown by experimental results,open-holes decreased tension and compression mechanical performance 42% and 46% respectively,and ETW environment have 17% and 23% decreasing influence on the compression mechanical performance of composite plate and plate with holes. Furthermore,the compression damage mechanism of composite plates and plates with holes are fiber compressing-shearing fracture after fiber buckling.展开更多
This work established a new analytical model based upon the equivalent constraint model （ECM） to constitute an available predictive approach for analyzing the ultimate strength and simulating the stress/strain respo...This work established a new analytical model based upon the equivalent constraint model （ECM） to constitute an available predictive approach for analyzing the ultimate strength and simulating the stress/strain response of general symmetric laminates subjected to combined loading, by taking into account the effect of matrix cracking. The ECM was adopted to mainly predict the in-plane stiffness reduction of the damaged laminate. Basic consideration that progressive matrix cracking provokes a re-distribution of the stress fields on each lamina within laminates, which greatly deteriorates the stress distributed in the primary load-bearing lamina and leads to the final failure of the laminates, is introduced for the construction of the failure criterion. The effects of lamina properties, lay-up configurations and loading conditions on the behaviors of the laminates were examined in this paper. A comparison of numerical results obtained from the established model and other existed models and published experimental data was presented for different material systems. The theory predictions demonstrated great match with the experimental observations investigated in this study.展开更多
文摘As composites are increasingly used in aircraft,composites-based the primary-load bearing structures were gradually considered for wide application. However,to determine worst case of the primary-load bearing structures of composites is quite necessary. In this paper,to reveal the effects on the mechanical performance of composite laminate plates were made,respectively by open holes and different environments. Firstly,we obtained the benchmark of composite plates by conducting tension and compression of room temperature and dry air( RTD),tension of cold temperature and dry air( CTD),and compression of elevated temperature and wet( ETW). Then opened circle holes were introduced into composite plates to know the influence of holes. Finally,CTD and ETW environment were respectively investigated to composite plate with holes being under tension and compression loads. As shown by experimental results,open-holes decreased tension and compression mechanical performance 42% and 46% respectively,and ETW environment have 17% and 23% decreasing influence on the compression mechanical performance of composite plate and plate with holes. Furthermore,the compression damage mechanism of composite plates and plates with holes are fiber compressing-shearing fracture after fiber buckling.
基金supported by the Natural Science Foundation Project of CQ CSTC(No.2009BB4290)the National Natural Science Foundation of China(No.10772105)the National Natural Science Association Foundation(NSAF) of China (No.10776023).
文摘This work established a new analytical model based upon the equivalent constraint model （ECM） to constitute an available predictive approach for analyzing the ultimate strength and simulating the stress/strain response of general symmetric laminates subjected to combined loading, by taking into account the effect of matrix cracking. The ECM was adopted to mainly predict the in-plane stiffness reduction of the damaged laminate. Basic consideration that progressive matrix cracking provokes a re-distribution of the stress fields on each lamina within laminates, which greatly deteriorates the stress distributed in the primary load-bearing lamina and leads to the final failure of the laminates, is introduced for the construction of the failure criterion. The effects of lamina properties, lay-up configurations and loading conditions on the behaviors of the laminates were examined in this paper. A comparison of numerical results obtained from the established model and other existed models and published experimental data was presented for different material systems. The theory predictions demonstrated great match with the experimental observations investigated in this study.
