As the controlled research of Dynamic Installation(DI)and Static Installation(SI),a new interference installation method was developed based on electromagnetic loading to enhance the mechanical properties of composite...As the controlled research of Dynamic Installation(DI)and Static Installation(SI),a new interference installation method was developed based on electromagnetic loading to enhance the mechanical properties of composite structures.Four different interference-fit sizes were considered,ranging from a net fit to 2.0%.The experiments were conducted to evaluate the installation resistance and the mechanical behavior of the joint under external loads.Meanwhile,an FFA model to model the stress distribution and damage behavior of the bolt-hole contact interface was established.The load-displacement curve and damage modes of experiments were used to verify the FEA results.The results show that the installation resistance during DI process was remarkably lower than that of SI process corresponding to all interference-fit sizes,and the stress amplitudes induced by interference were larger and widely distributed.The damage of the hole wall was positively correlated with interference fit size,but DI can significantly reduce the damage compared to SI.In performance tests,DI enhanced the static bearing capacity and extended longer fatigue life of the joints than SI.DI methods can be an effective way to achieve highly reliable interference joints in composite structures.展开更多
This paper investigates the “brush-like”deformation phenomenon of the contact interface at the bolt-hole during the interference-fit installation of high-locking bolts under static loading in CFRP connection structu...This paper investigates the “brush-like”deformation phenomenon of the contact interface at the bolt-hole during the interference-fit installation of high-locking bolts under static loading in CFRP connection structures.An innovative theoretical model is proposed to predict axial installation force,specifically designed for moderate interference-fit.This model is based on the “brush-like”deformation of the hole wall,with the axial installation force predicted through force analysis and theoretical calculations,effectively overcoming the limitations of prior models that idealized the contact interface at the bolt-hole.The predictions generated by this theoretical model align closely with experimental data,confirming its efficacy in accurately forecasting the curve of installation force for interferencefit bolts during the static installation within the moderate interference-fit range.Additionally,a comprehensive analysis of the relationship between deformation of the hole wall and curves of installation force across small,moderate,and large interference-fit levels are presented.It is demonstrated that the degree of deformation within the moderate interference-fit range is more suitable than that in the small and large interference-fit ranges,making it a reliable alternative for installation force tests within this range during static installation.The moderate interference-fit domain[1.00%,1.24%]is established as a validated and optimal range of interference-fit bolts for the static installation.展开更多
基金co-supported by the National Commercial Aircraft Manufacturing Engineering Innovation Fund,China(No.COMAC-SFGS-2-22-1816)Shaanxi Province Key Research and Development Program Projects,China(No.2022GXLH-02025)Shaanxi Province 100 Scientific and Technological Achievements Transformation Action Projects,China(No.2021CGBX-11)。
文摘As the controlled research of Dynamic Installation(DI)and Static Installation(SI),a new interference installation method was developed based on electromagnetic loading to enhance the mechanical properties of composite structures.Four different interference-fit sizes were considered,ranging from a net fit to 2.0%.The experiments were conducted to evaluate the installation resistance and the mechanical behavior of the joint under external loads.Meanwhile,an FFA model to model the stress distribution and damage behavior of the bolt-hole contact interface was established.The load-displacement curve and damage modes of experiments were used to verify the FEA results.The results show that the installation resistance during DI process was remarkably lower than that of SI process corresponding to all interference-fit sizes,and the stress amplitudes induced by interference were larger and widely distributed.The damage of the hole wall was positively correlated with interference fit size,but DI can significantly reduce the damage compared to SI.In performance tests,DI enhanced the static bearing capacity and extended longer fatigue life of the joints than SI.DI methods can be an effective way to achieve highly reliable interference joints in composite structures.
基金co-supported by the National Natural Science Foundation of China(Nos.52275165 and 52305146)the Sichuan Science and Technology Program,China(Nos.2023YFG0165 and 2023NSFSC0372)+1 种基金the Sichuan Province Engineering Technology Research Center of General Aircraft Maintenance Project,China(No.GAMRC2023ZD03)the Student Innovation Fund Project,China(No.24CAFUC10202)。
文摘This paper investigates the “brush-like”deformation phenomenon of the contact interface at the bolt-hole during the interference-fit installation of high-locking bolts under static loading in CFRP connection structures.An innovative theoretical model is proposed to predict axial installation force,specifically designed for moderate interference-fit.This model is based on the “brush-like”deformation of the hole wall,with the axial installation force predicted through force analysis and theoretical calculations,effectively overcoming the limitations of prior models that idealized the contact interface at the bolt-hole.The predictions generated by this theoretical model align closely with experimental data,confirming its efficacy in accurately forecasting the curve of installation force for interferencefit bolts during the static installation within the moderate interference-fit range.Additionally,a comprehensive analysis of the relationship between deformation of the hole wall and curves of installation force across small,moderate,and large interference-fit levels are presented.It is demonstrated that the degree of deformation within the moderate interference-fit range is more suitable than that in the small and large interference-fit ranges,making it a reliable alternative for installation force tests within this range during static installation.The moderate interference-fit domain[1.00%,1.24%]is established as a validated and optimal range of interference-fit bolts for the static installation.
