In aircraft assembly, interlayer burr formation in dry drilling of stacked metal materials is a common problem. Traditional manual deburring operation seriously affects the assembly qual- ity and assembly efficiency, ...In aircraft assembly, interlayer burr formation in dry drilling of stacked metal materials is a common problem. Traditional manual deburring operation seriously affects the assembly qual- ity and assembly efficiency, is time-consuming and costly, and is not conducive to aircraft automatic assembly based on industrial robot. In this paper, the formation of drilling exit burr and the influ- ence of interlayer gap on interlayer burr formation were studied, and the mechanism of interlayer gap formation in drilling stacked aluminum alloy plates was investigated, a simplified mathematical model of interlayer gap based on the theory of plates and shells and finite element method was established. The relationship between interlayer gap and interlayer burr, as well as the effect of feed rate and pressing force on interlayer burr height and interlayer gap was discussed. The result shows that theoretical interlayer gap has a positive correlation with interlayer burr height and preloading nressing force is an effective method to control interlaver burr formation.展开更多
The ability of perceiving external pressures and conducting corresponding signals is one of the important functions of flexible electronics,which has been widely studied in electronic skin,prosthetics,robotics,healthc...The ability of perceiving external pressures and conducting corresponding signals is one of the important functions of flexible electronics,which has been widely studied in electronic skin,prosthetics,robotics,healthcare,human-machine interfaces,etc.Pressure sensor should not be limited to the detection of unidirectional pressure.Here,a leather-based electronic pressure sensor and corresponding arrays with bidirectional sensing capability are demonstrated.The sensor/arrays consisting of two pieces of stacked leather both modified with acidified carbon nanotubes(a-CNTs)can achieve multi-level response to pressure over a broad working range and sense pulling force opposite to pressure.With polyurethane mixed with ferriferrous oxide(Fe3O4)powder being applied to their upper surface,the resistive sensor/individual units of arrays can also detect the magnetic field because of the contactless pulling force generated by the magnetized Fe3O4.Being able to sense pressure,pulling force and magnetic field,the leather-based electronic bidirectional pressure sensor and corresponding arrays with good performance not only exhibit potential for mass production and their broad application prospects,but also provide a new insight for the development of flexible electronics.展开更多
基金the financial support of the Aeronautical Science Foundation of China(Nos.2013ZE52067,2014ZE52057)
文摘In aircraft assembly, interlayer burr formation in dry drilling of stacked metal materials is a common problem. Traditional manual deburring operation seriously affects the assembly qual- ity and assembly efficiency, is time-consuming and costly, and is not conducive to aircraft automatic assembly based on industrial robot. In this paper, the formation of drilling exit burr and the influ- ence of interlayer gap on interlayer burr formation were studied, and the mechanism of interlayer gap formation in drilling stacked aluminum alloy plates was investigated, a simplified mathematical model of interlayer gap based on the theory of plates and shells and finite element method was established. The relationship between interlayer gap and interlayer burr, as well as the effect of feed rate and pressing force on interlayer burr height and interlayer gap was discussed. The result shows that theoretical interlayer gap has a positive correlation with interlayer burr height and preloading nressing force is an effective method to control interlaver burr formation.
基金the National Natural Science Foundation for Distinguished Young Scholars(Grant No.21625401)the National Natural Science Foundation of China(Grant Nos.21727808,21574065,21604038,21504043,21604040 and 51702155)+2 种基金the Jiangsu Provincial Founds for Natural Science Foundation(Grant Nos.BK20160975,BK20160981 and BK20170975)the Program for Outstanding Young Scholars from the Organization Department of the CPC Central Committee,the National Key Basic Research Program of China(Grant No.2015CB932200)the National Key R&D Program of China(Grant No.2017YFA0207201)。
文摘The ability of perceiving external pressures and conducting corresponding signals is one of the important functions of flexible electronics,which has been widely studied in electronic skin,prosthetics,robotics,healthcare,human-machine interfaces,etc.Pressure sensor should not be limited to the detection of unidirectional pressure.Here,a leather-based electronic pressure sensor and corresponding arrays with bidirectional sensing capability are demonstrated.The sensor/arrays consisting of two pieces of stacked leather both modified with acidified carbon nanotubes(a-CNTs)can achieve multi-level response to pressure over a broad working range and sense pulling force opposite to pressure.With polyurethane mixed with ferriferrous oxide(Fe3O4)powder being applied to their upper surface,the resistive sensor/individual units of arrays can also detect the magnetic field because of the contactless pulling force generated by the magnetized Fe3O4.Being able to sense pressure,pulling force and magnetic field,the leather-based electronic bidirectional pressure sensor and corresponding arrays with good performance not only exhibit potential for mass production and their broad application prospects,but also provide a new insight for the development of flexible electronics.
