Design And Analysis Of High Load And Low Impact Separating Device Driven By SMA

After the satellite is launched with the carrier rocket,it is necessary to separate the satellite from the rocket at an appropriate time to ensure that the satellite enters the intendedorbit.In this process,it is vital to ensure a reliable connection and accurate separation.With the development of aerospace technology,the demand for launching heavy payloads in space is increasingly widespread.At the same time,increasingly sophisticated,diversified and flexible sensitive devices and optical equipment are more sensitive to the impact and vibration environment caused by on-orbit release.Traditional explosive actuators will produce great unlocking impact and chemical pollution.Therefore,it is of great significance to carry out research on non-explosive connection and separation technology.Today,the development of non-fire technology is mainly concentrated in the field of new intelligent materials,among which the research based on shape memory alloy has achieved rich results.In this article,a SMAdriven wire connection and separation device is developed on the background of large load and low impact satellite-rocket connection and separation.Based on the low impact release of space heavy load,we propose a connection scheme of locking release device driven by smart material shape memory alloy combined with C-type elastic band.According to the principle scheme,the locking and releasing device and the wrapping system are designed in detail respectively.For the locking release device,the trigger scheme of offset SMA driver is preferred,and the SMA wire trigger secondary swing arm limiting structure combined with pulley wear reduction scheme is proposed.Stress analysis is carried out on the limiting structure and design check of key parameters is carried out.According to the bag system,a C-type elastic bag is proposed to replace the traditional multi-section bag,and the detailed design of the separation component and the storage component is completed at the same time.The mechanical model of the loading process of the separation device is established,and the stress distribution characteristics and dangerous cross-section parameters of the band in the elastic deformation stage and the loading pretightening stage are obtained.The stress law of the band under the condition of variable input is analyzed.Static strength analysis is carried out for non-selflocking threads of key connection structures.A simplified model of the locking and releasing device and the strap system in the connected state is established and static load analysis is carried out.The dynamic simulation of the locking and releasing device and the band system is carried out to obtain the dynamic response characteristics of the unlocking and releasing process of the device.The energy transfer path of unlocking process is analyzed,and the energy transfer model is established.The functions and performance indexes of the whole separator are verified by means of simulation and experiment.Through thermal environment analysis,modal analysis and random vibration analysis,the thermal deformation of the device in the space environment is simulated,the modal parameters of the system are identified,the fundamental frequency and mode shape of the vibration are obtained,and the adaptability of the device to random vibration is verified.A testing platform for SMA actuators was set up to test key parameters such as mechanical properties and reaction time of SMA wires.The principle prototype of the linear separation device is developed,and an experimental platform is built to verify the unlocking and resetting functions of the locking and releasing device.Meanwhile,the performance indexes such as unlocking force,unlocking time and ultimate bearing are tested.The band system and the locking and releasing device are assembled together to detect the unlocking performance of the whole separating device.