Separation Security Of Fragments During Linear Explosive Separation Process

Linear separation device is a key part of rocket launcher and the performance of it has significant impact on launch mission.Previous investigations mainly focused on separation reliability,while security after separation was neglected.Besides,traditional design of the device was mainly based on former practices,yet an understanding of separation mechanism was lack.Aiming at improving separation security,the present paper studies several key scientific problems involved,and quantitative influence of relevant factors on fragment scattering performance is presented.Without loss of generality,a typical mild detonations fuse(MDF)actuated linear explosive separation device was selected to do the research,with cast aluminum alloy ZL205 A chosen as separation plate material.Dynamic properties especially dynamic fracture response of the material were chaterized by SHTB tensile test,mode I and I/II mixed mode fracture test.Energy output mechanism of MDF was theoretically predicted based on momentum theorem and verified by experiment and simulation results.Linear explosive separation experiments were carried out to obtain fragment scattering performance,including scattering angle,flying velocity and length of fragments.Besides,more fragment velocity data was obtained by numerical simulation.On this basis,energy partition of MDF during separation process was theoretically analysed based on assumption of work efficiency.Based on structural failure criterion,shear slip accumulation theory and derormation chacter of separation plate,quantitative relationship bewteen key factors and fragment scattering performance was established.These relevant factors include key material parameter,structure parameter and MDF features.All the relations were verified by results of experiments and simulations.Conclusions and research methods of the present paper would provide effective scientifical support and reference for design of linear explosive separation device.