Topology Optimization for Mass Reduction of a Structural Component in a Surgical Robotic Arm

Abstract

This paper presents a case study on the topology optimization of a structural component in a surgical robotic arm, aiming to reduce mass while maintaining mechanical performance. The component, made of aluminium alloy Al7075-T6, was subjected to finite element analysis and topology optimization using Altair OptiStruct. The objective of the study was to minimize mass under the imposed constraints of maximum displacement (≤ 0.2 mm) and von Mises stress (≤ 250 MPa). The stress limit was selected as 50% of the alloy’s yield strength (≈ 503 MPa), to ensure an additional safety margin. Finite element analysis (FEA) was employed to evaluate and validate the optimized geometry. The initial design exhibited a displacement of 0.21 mm and a maximum stress of 240 MPa, which corresponds to a safety factor of 1.04. After optimization, the final design achieved a displacement of 0.18 mm and a maximum stress of 227 MPa, which results in a safety factor of 1.3. These results demonstrate that the adopted topology optimization strategy can effectively reduce structural mass (≈34%) while maintaining compliance with displacement and stress constraints, ensuring reliability for robotic applications.