Simulation Analysis and Optimization of the Mold-Changing Robot Structure for a Six-Station Cold Heading Machine

Background: Automated mould replacement in six-station cold heading machines requires a frame that balances reduced mass with acceptable static deformation and dynamic behaviour. Aim: This study examines that trade-off using recorded finite-element results for an original frame and a hollow-section redesign. Methods: A simplified model of the frame was investigated in ANSYS Workbench using static structural and constrained modal analyses. The first six natural frequencies of the original frame were compared with nominal motor, pneumatic, and motion repetition frequencies. Seventeen recorded square-tube dimension combinations were reviewed, alongside the reported response-surface candidate and the selected redesign. Data consistency and available validation evidence were assessed. Results: The original frame had a reported mass of 521.93 kg, maximum equivalent stress of 14.577 MPa, and maximum total deformation of 0.12662 mm. For the hollow-section redesign, corresponding values were 270.73 kg, 8.6661 MPa, and 0.24265 mm, representing reductions of 48.13% in mass and 40.55% in stress, but an increase of 91.64% in deformation. The original frame's first six natural frequencies ranged from 9.9 to 78.7 Hz. Inconsistent parameter-study records, undefined numerical acceptance limits, and missing final-design dynamic validation limited conclusions about optimality and resonance avoidance. Conclusion: Hollow square tubing offers a potential mass-saving configuration, but the recorded results do not establish sufficient stiffness, positioning accuracy, or dynamic acceptability. Verified input data, design constraints, convergence testing, and experimental assessment are required before engineering acceptance.