Rigid-Body Modelling of Forklift Masts and Mast Sway Simulations
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Reach truck masts are subjected to oscillations, which have signiﬁcant impacts on the dynamics of the entire vehicle. Mast oscillations can cause undesirable outcomes in extreme situations and therefore it is desirable to be able to predict these outcomes before they occur. A forklift manufacturer in Mjölby initiated a thesis with the intention to obtain a model that can simulate mast sway for situations where oscillations occur. The objective of the thesis was to create a model of Triplex masts and ﬁnd dependencies between model parameters and variables such as fork height and load.
The thesis was conducted modelling the mast with a rigid multibody approach where torsion springs and dampers were used between mast parts to simulate mast elasticity. Clearance at the connections were considered and included in the model. The obtained model constitutes of 8 parameters that could be tuned to attain diﬀerent oscillation characteristics. Parametric optimisation was carried out to ﬁnd optimal sets of parameters for compliance with sway measurement tests with diﬀerent load and fork height cases.
The thesis has resulted in a model that is able to simulate mast sway with diﬀerent oscillation characteristics depending on model parameters. Performed parametric optimisation resulted in parameters that reveal useful information about how model parameters depend on load and fork height. The method used for obtaining optimal parameters can likewise be applied to other mast models in order to gain insight into model parameters as functions of load and fork height.
Place, publisher, year, edition, pages
2016. , 70 p.
Forklift, MBS, Simulation, Mast, Mast Sway, SimXpert, Oscillations, Rigid-body, Modelling, Reach truck
Applied Mechanics Control Engineering
IdentifiersURN: urn:nbn:se:liu:diva-129529ISRN: LiTH-ISY-EX--16/4960--SEOAI: oai:DiVA.org:liu-129529DiVA: diva2:940179
Subject / course
2016-06-08, Algoritmen, Linköping, 14:00 (English)
Erdemir, SertacFredin, Jim
Gunnarsson, Svante, Professor