This research paper studies the static stability of six kinds of scissor lifts with one input force of hydraulic
actuator by having the input on the lines of the nodes of the scissor lifts. Firstly, the static stability of single scissor arm is
studied by using energy method and modeling method in the software Nastran. The stability results of two methods are
then compared. Subsequently, the scissor lift models with hydraulic actuators are prepared to analyze the static stability.
The static stability of six kinds of scissor lifts is compared. It is thus found that the results of the overall model are closer
to the actual situation. The analysis of single arm models has made it easier to compare the theoretical solutions and
modeling solutions thus the study on stability of single scissor arm has been proved to be meaningful.