Optimize Robotic Arm Design for Fatigue Loading Using ANSYS for Multiple Materials

Abstract

This study presents a comparative structural analysis of a robotic arm subjected to combined loads and applied moments at one end, while the opposite end remains fixed. The deflection results indicate that minimum displacement occurs at the fixed end (0.0 m), whereas maximum deflection appears at the loaded end, reaching 0.00026 m for the base material. The equivalent stress distribution varies from 7.22 × 10? Pa to 3.075 × 10? Pa, with minimum stress typically occurring at the mid-section and maximum stress near the loaded or constrained regions. Similar mechanical behaviour is observed for ABS polymer, where the deflection ranges from 0 to 0.0137 m, and the equivalent stress varies between 7.24 × 10? Pa and 3.06 × 10? Pa. Titanium also follows the same pattern, showing a minimum deflection of 0 m at the lower end and a maximum of 0.000133 m at the upper end, with equivalent stress ranging from 7.23 × 10? Pa to 3.03 × 10? Pa. Fatigue analysis reveals that the safety factor varies between 0.8125 and 15, reflecting the influence of cyclic loading on arm life. The fatigue life decreases significantly when applied load increases to 150%, whereas a 50% reduction in load enhances the life beyond 10? cycles, approaching theoretical infinite life. Overall, the results demonstrate that increasing arm dimensions or reducing load effectively improves the structural and fatigue performance of the robotic arm across all materials studied.

Introduction

Robots are programmable machines designed to perform tasks with high accuracy, efficiency, and safety, often in environments that are repetitive, hazardous, or require precision. Robotics integrates mechanical, electrical, and computer engineering with artificial intelligence, enabling applications across manufacturing, healthcare, defense, space, agriculture, and services. Among robotic systems, robotic arms are especially important because they replicate human arm movements using links, joints, actuators, sensors, and end-effectors to perform tasks such as assembly, welding, surgery, and material handling.

Recent research in robotic arms highlights advances in lightweight design, flexible and multi-arm systems, intelligent and adaptive control, and AI-based coordination. Applications range from industrial automation and precision agriculture to medical surgery, underwater operations, and space exploration. Despite progress, key research gaps remain, including limited real-world experimental validation, lack of unified multi-arm coordination frameworks, partial integration of AI for autonomous decision-making, and challenges in balancing stiffness with lightweight materials.

This study focuses on the structural performance of a robotic arm using finite element analysis in ANSYS. The objectives include analyzing deflection, stress distribution, and fatigue behavior under combined loads and moments, and comparing different materials—base material, ABS polymer, and titanium—under identical conditions. The methodology applies the Finite Element Method (FEM), covering geometry creation, meshing, boundary conditions, solution, and post-processing.

Results show that maximum deflection occurs at the free end of the arm, while minimum deflection is at the fixed end for all materials. Stress is distributed throughout the arm, with maximum stress near the fixed end and lower values elsewhere. ABS polymer exhibits significantly higher deflection compared to the base material and titanium, while titanium shows the lowest deflection and comparable stress levels. Overall, the analysis demonstrates that material choice strongly influences deformation and fatigue performance, with titanium offering superior stiffness and suitability for high-precision robotic arm applications.

References

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Copyright

Copyright © 2025 Simpy Kumari, Vikas Kumar Shukla. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.