Lattice composite structures as applied to fuselage barrel of a civil aircraft demonstrate high weight efficiency and capability to bear all external loads,typical for such kind of structures.One of the critical probl...Lattice composite structures as applied to fuselage barrel of a civil aircraft demonstrate high weight efficiency and capability to bear all external loads,typical for such kind of structures.One of the critical problems of lattice structures is low impact resistance,as such structure consists of unidirectional ribs,which residual strength drops severely even after an impact of a quite low energy.The impacts typical for fuselage barrel are low-velocity impacts of hail,small stones from the airdrome etc.with the level of impact energy up to 30–50 J.Low impact resistance of lattice composite fuselage structures leads to the necessity of its full protection against impacts.This means implementation of additional protective structure elements and thus increase of the structure weight.The scope of this study was to make a first approximation of the weight of protective elements for lattice fuselage structures based on impact tests of composite specimens with protection.The specimens consisted of unidirectional composite ribs with rectangular cross-section,manufactured by an industrial technology based on wet winding method,plastic protective hat put on an upper fringe of the rib and an elastic tape,wrapping together the rib and the hat.Specimens were put on a substrate to take into account the compliance of lattice structure and displacements of ribs at impact due to the quasi-static force.According to the standards of impact strength tests of aircraft components,one-inch impactor simulating a small stone,acting on a fuselage structure during aircraft take-off was used.The specimens were tested on low-velocity impact with energies from 10 to 50 J.Before and after the impact an ultrasound control was performed to check if any delamination occurred.For comparison,a number of unidirectional ribs with no protection were tested.展开更多
基金The financial support from the Ministry of Science and High Education of the Russian Federation(Project identification number RFMEFI62818X0009)is gratefully acknowledged.
文摘Lattice composite structures as applied to fuselage barrel of a civil aircraft demonstrate high weight efficiency and capability to bear all external loads,typical for such kind of structures.One of the critical problems of lattice structures is low impact resistance,as such structure consists of unidirectional ribs,which residual strength drops severely even after an impact of a quite low energy.The impacts typical for fuselage barrel are low-velocity impacts of hail,small stones from the airdrome etc.with the level of impact energy up to 30–50 J.Low impact resistance of lattice composite fuselage structures leads to the necessity of its full protection against impacts.This means implementation of additional protective structure elements and thus increase of the structure weight.The scope of this study was to make a first approximation of the weight of protective elements for lattice fuselage structures based on impact tests of composite specimens with protection.The specimens consisted of unidirectional composite ribs with rectangular cross-section,manufactured by an industrial technology based on wet winding method,plastic protective hat put on an upper fringe of the rib and an elastic tape,wrapping together the rib and the hat.Specimens were put on a substrate to take into account the compliance of lattice structure and displacements of ribs at impact due to the quasi-static force.According to the standards of impact strength tests of aircraft components,one-inch impactor simulating a small stone,acting on a fuselage structure during aircraft take-off was used.The specimens were tested on low-velocity impact with energies from 10 to 50 J.Before and after the impact an ultrasound control was performed to check if any delamination occurred.For comparison,a number of unidirectional ribs with no protection were tested.
