Modal Design Optimization of an Articulated Frame

The favorable maneuverability and road adaptability of heavy articulated dump trucks (ADT) is leading to their increased usage in many countries. This paper presents a process for designing an articulated chassis frame, as in an ADT, based on its dynamic properties. The finite element method (FEM), employing the Lanczos modal analysis algorithm, is used to perform modal and sensitivity analyses and evaluate dynamic characteristics of an articulated chassis frame based on its three-dimensional digital design. Several finite element models are constructed in order to find the six lowest natural frequencies and mode shapes for different steering angles. The weight of the articulated chassis frame is optimized through the sensitivity analysis method controlled by the first natural frequency and the thickness of the frame components. The weight of the optimized chassis frame is reduced by 241 kg (about 7.10% of the total frame weight), the maximum flexural rigidity of the frame is reduced by 4.34%, and the first natural frequency is increased from 10.2 to 10.8 Hz. The dynamic characteristics of the optimized frame are evaluated according to principles of vehicle vibration to ensure that the design can adequately meet the dynamic performance requirements of a frame in a real truck.