A B S T R A C T
The study aims to optimize the design of a six-degree-of-freedom robotic arm using advanced composite materials
specifically carbon/polyester fiber-reinforced composites to achieve a lightweight yet stiff structure with
superior dynamic performance. The main contribution of this article is the development of a dynamic optimization
framework that integrates a gradient-based optimization technique with the finite element method (FEM)
to model and analyze the flexible robotic arm incorporating flexible joints. This approach carefully derives the
equations of motion to fully capture all dynamic coupling effects within the system including the influence of
joint torsional stiffness on both flexible links and joints. The optimization process focuses on minimizing the
overall displacement while reducing the robot arm’s mass, inertia and enhancing its dynamic capabilities. Using
the block Lanczos method implemented in MATLAB R2021a to calculate the natural frequencies and compares
the original aluminum design with the optimized composite arm. The results demonstrate a significant
improvement in stiffness along with a notable reduction in mass and inertia. Consequently, the optimized robot
arm achieves exceptional specific stiffness, strength and enabling an increase in the load capacity at the end
effector by up to 30 %.