Abstract: In order to study the response characteristics of the scissor-type deployable element under vibration conditions, the study used the ship rust removal device as the vibration source and firstly established the mechanical model of the scissor-type deployable element. And the reliability of the element members under extreme conditions was studied. Then it used numerical modal analysis method and dynamic stress test analysis method under random vibration to study the random excitation problem and response of the scissor expandable unit under vibration conditions. It proposed a method to eliminate the second-order transverse bending vibration and excitation resonance of the scissor expandable unit and carried out dynamic stress simulation for each structural optimization scheme. The results show that the second-order modal vibration (306.15Hz) of the scissor-type deployable unit and the random excitation resonance generated by rust removal are the main reasons for the vibration fatigue of the scissor-type deployable unit. The dynamic stress level of the unit can be reduced most significantly by increasing the thickness of the upper worktable from 10mm to 14mm, reducing the rigidity of the worktable from 20GPa to 19.5GPa, and adding a connecting shaft between the two connecting rods. The research results can provide a theoretical basis for the stable and reliable operation of the scissor deployable unit in engineering applications.

Key words: scissor structure, unfolding process, modal analysis, random vibration, structure optimization