| dc.description.abstract | The main purpose of the thesis is to developed a new type of separation mechanisms with a non-explosive actuator (NEA mechanism), and to validate its functions through various tests. The results of the research can not only improve the independent design and develop abilities of domestic aerospace research, but also can fulfill the requirements for separation of the satellite mission or the sounding rockets missions in Taiwan.
In this study, the related literature and patents about NEA mechanism are searched and analyzed systematically. A morphological chart was thus established, from that the concept design was derived together with “principle of toggle point ” and “principle of self-help”. The new type of NEA mechanism with a flat design involves two modules, namely (a) the non-explosive actuator and (b) the separation mechanism. The Non-explosive actuator used the hot-melting wire as triggering device, which is triggered by high current. The separation mechanism is designed with a split nut for connection with a bolt. It is designed as to support a static load of 50 kg as well as an impact load of 10G. It is also able to remain the connection under random vibration of 6G while no trigger signal is available. A prototype of the NEA mechanism based on the detail design is built for the validation tests.
The function validation tests are initiated to ensure the proposed NEA mechanism having the capability of fulfillment of various requirements of the missions. The conducted tests are (i) static load test, (ii) impact load test, (iii) random vibration test and (iv) measurement of the separation impact. In the static load test, the separation performance of the NEA mechanism is conducted on a force closure fixture with a manually operated hydraulic pump for load generation. Both the impact load test and random vibration test were conducted on a “vertical move-in vibration test machine”, following to the environment testing process for sounding rocket payload’s acceptance.
After all tests validate that NEA mechanism can not only pass through the static load test and impact load test, but also the vibration load test. The separation time by the static load test and by the dynamic load test is about 0.4 seconds and 0.2 seconds, respectively. A possible reason for this time difference is the dynamic micro-setting effect. By conducting an experiment for micro-setting, it is very clear that dynamic vibration load do shorten the separation time. At last, we measure the impact with the accelerometer, which caused by the separation. The max acceleration is detected at the opposite of the bolt detachment axis direction, which is approximate 7.4G.
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