Telehandler Stability Analysis Using a Virtual Tilt & Rotation Platform

This paper investigates the stability of telescopic handlers operating on inclined terrain through a sequential methodological approach. In a first stage, stability is assessed using quasi-static methods based on force and moment equilibrium, including the load transfer matrix and the stability pyramid. These approaches account for gravitational and inertial effects through equivalent external forces and moments applied at the global centre of gravity, enabling an efficient evaluation of load redistribution and proximity to rollover thresholds under generalized quasi-static conditions.The application of these methods highlights intrinsic limitations when addressing structurally complex systems, such as telehandlers equipped with a pivoting rear axle, and when interpreting certain results obtained from standardized stability tests. To overcome these limitations, a dynamic multibody model based on the three-dimensional Bond Graph (3D Bond Graph) methodology is subsequently introduced. This virtual model is not intended to replace the quasi-static analyses, but to complement them by providing a physically consistent interpretation of the observed behaviour.The dynamic model is implemented within a virtual tilting and rotation test platform and validated against experimental results obtained from ISO 22915-14 stability tests. The comparison confirms compliance with the normative requirements and demonstrates that the model captures different rollover modes and transitions between virtual stability axes that cannot be fully explained by quasi-static approaches alone. Unlike most previous studies, which focus on fixed orientations and isolated configurations, the proposed framework analyses how stability evolves as the vehicle changes its orientation on inclined terrain. This contributes to a more realistic assessment of operating conditions and supports the use of dynamic simulation as a complementary tool for test interpretation, experimental planning, and the future development of predictive stability and operator assistance systems.