The development of a dynamic scissor lift model

Abstract

Tip-over/rollovers are the most frequent cause of fatalities associated with the use of scissor lifts. The objective of this study is to develop a dynamic model of a scissor lift to investigate tip-overs. A multibody dynamic model of a typical scissor lift was created using an advanced modeling platform-ADAMS ®. This model was statically validated and dynamically calibrated based on experimental results from center of gravity, curb impact, and pothole depression tests. The dynamic responses of the scissor lift model were consistent with the experimental data. Once calibrated/validated, the model was used to simulate hazardous scenarios while varying the scissor lift's flexibility. Results of the simulations indicate that increased flexibility reduces the scissor lift's stability. This developed scissor lift model could be used to perform additional simulated conditions and for design optimization.

Assessment of Fall-Arrest Systems for Scissor Lift Operators

“…Further investigation is needed using modifications to the computer model that represent more realistic conditions of the scissor lift, such as significant stiffness reduction resulting from damage to joints/structures of the lift because of aging and normal wear. The effects of such deterioration were observed in automobile suspension systems (Dukkipati, Pang, Qatu, Sheng, & Shuguang, 2008) subjected to extreme weather, poor maintenance, soft ground operational conditions, or any combination of these factors (Hartsell, 2010).…”

“…Therefore, the extrapolation of our findings to elevating platforms with multiple occupants should be done with caution, as elevating platform characteristics for such platforms might differ under conditions with multiple occupants. In addition, dynamic test procedures followed by ANSI A92.6 recommendations and associated computer modeling were performed (Hartsell, 2010). Numerous other avenues of research could profitably be followed here because questions of dynamic actions of the lift or occupants, task performance, slope and motion, body orientation during falling, propulsion of occupants on sudden platform motion, and various other avenues of research suggest mechanisms of injury causation, and these mechanisms are at this point little understood.…”

“…The model was also validated and refined using the time histories of the lift dynamic responses measured in these physical experiments. Simulated operator information was then incorporated into the completed and validated scissor lift model ( Figure 2) using LifeMOD Biomechanics Human Modeler (Version 2010, LifeModeler Inc., San Clemente, CA), which is a plug-in to the ADAMS software (Hartsell, 2010).…”

“…The objectives of this study were twofold: (a) to further evaluate the stability of the lift and the performance of various fall-arrest harnesses and lanyards using manikin drop tests and computer modeling and (b) to evaluate/predict the dynamic loading to the head/neck of a scissor lift operator caused by fall-arrest forces by using a dynamic simulation model that includes the scissor lift (Hartsell, 2010;Ronaghi et al, 2009) and the manikin.…”

Kinetostatic analysis of a scissor jack mechanism powered by a tetrad RRR-Ta-RRR

“…Other researches about this mechanism were done by researchers from different countries, each of them trying to improve it. [4][5][6][7][8][9][10][11].…”