Topology Optimization for Mass Reduction of a Structural Component in a Surgical Robotic Arm
Keywords:
topology optimization, surgical robot, Altair OptiStruct, structural analysis, Al7075-T6, robotic arm component
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.
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References
[1]. Batista R. C., et al., Lattice-based topology optimization of robot arm components for additive manufacturing, Front. Mech. Eng, 10, 1422539, 2024.
[2]. Curkovic P., Comparative Analysis of Topology Optimization Platforms for Additive Manufacturing of Robot Arms, Designs, 8, 98, 2024.
[3]. Sha L., et al., A topology optimization method of robot lightweight design based on the finite element model of assembly and its applications, Sci. Prog, 103(3), p. 36850420936482, 2020.
[4]. Langelaar M., Topology optimization of 3D self-supporting structures for additive manufacturing, Addit. Manuf, 12(Part A), p. 60-70, 2016.
[5]. Jia J., Sun X., Structural Optimization Design of a Six Degrees of Freedom Serial Robot with Integrated Topology and Dimensional Parameters, Sensors, 23(16), p. 7183, 2023.
[6]. Chen J., Chen Q., Yang H., Additive manufacturing of a continuum topology-optimized palletizing manipulator arm, Mech. Sci, 12, p. 289-304, 2021.
[7]. Dammer G., et al., Design, topology optimization, and additive manufacturing of a pneumatically actuated lightweight robot, Actuators, 12(7), p. 266, 2023.
[8]. El Khadiri I., et al., Topology optimization methods for additive manufacturing: A review, Int. J. Simul. Multidisci. Des. Optim, 14, p. 12, 2023.
[9]. Fernandez E., et al., Topology optimisation for large-scale additive manufacturing: generating designs tailored to the deposition nozzle size, Virtual Phys. Prototyping, 16(2), p. 196-220, 2021.
[10]. Pinskier J., et al., Automated design of pneumatic soft grippers through design-dependent multi-material topology optimization, Proc. IEEE Int. Conf. Soft Robotics (RoboSoft), 2023.
[11]. Silva G. A., Beck A. T., Sigmund O., Stress-constrained topology optimization considering uniform manufacturing uncertainties, Comput. Methods Appl. Mech. Eng, 344, p. 512-537, 2019.
[12]. Suresh S., et al., Topology optimization for transversely isotropic materials with high-cycle fatigue as a constraint, Struct. Multidiscip. Optim, 63, p. 161-172, 2021.
[13]. Sigmund O., Maute K., Topology optimization approaches: A comparative review, Structural and Multidisciplinary Optimization, 48(6), p. 1031-1055, 2013.
[14]. Suresh S., et al., Topology optimization using a continuoustime high-cycle fatigue model, Struct. Multidiscip. Optim, 61, p. 1011-1025, 2020.
[15]. Liu K., Tovar A., An efficient 3D topology optimization code written in Matlab, Structural and Multidisciplinary Optimization, 50(6) p. 1175-1196, 2014.
[16]. Oh M. K., Lee D. S., Yoo J., Stress-constrained topology optimization simultaneously considering the uncertainty of load positions, International Journal for Numerical Methods in Engineering, 123(3), p. 339-365, 2022.
[17]. Granlund G., et al., Stress-constrained topology optimization of structures subjected to non-proportional loading, Int. J. Numer. Methods Eng, 124(12), p. 2818-2836, 2023.
[18]. Kranz M., Lüdeker J. K., Kriegesmann B., A generalized approach for robust topology optimization using the first-order second-moment method for arbitrary response functions, Structural and Multidisciplinary Optimization, 66, 98, 2023.
[19]. Murat F., Kaymaz I., Şensoy A. T., Reliability-Based Topology Optimization Considering Overhang Constraints for Additive Manufacturing Design, Applied Sciences, 15(11), 6250, 2025.
[20]. Martínez-Frutos J., Herrero-Pérez D., Robust topology optimization of continuum structures, Computers & Structures, 257, 106677, p. 1-15, 2021.
[21]. Yun G. H., Topology optimization considering the fatigue constraint of variable amplitude load based on the equivalent static load approach, Appl. Math. Model, 56, p. 626-647, 2018.
[22]. Hermansen S. M., Lund E., Multi-material and thickness optimization of laminated composite structures subject to highcycle fatigue, Struct. Multidisc. Optim, 66, p. 259, 2023.
[23]. Tang H., et al., Numerical Prediction of Fatigue Life for Landing Gear Considering the Shock Absorber Travel, Aerospace, 12(1), p. 42, 2025.
[24]. Senhora F. V., Topology optimization with local stress constraints and continuously varying load direction, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 478(2260), 20220436, 2023.
[25]. Venkatesh S., et al., A review on aluminium 7075 alloy: Micro structure, mechanical properties and application, AIP Conf. Proc, 3221, p. 020001, 2024.
[2]. Curkovic P., Comparative Analysis of Topology Optimization Platforms for Additive Manufacturing of Robot Arms, Designs, 8, 98, 2024.
[3]. Sha L., et al., A topology optimization method of robot lightweight design based on the finite element model of assembly and its applications, Sci. Prog, 103(3), p. 36850420936482, 2020.
[4]. Langelaar M., Topology optimization of 3D self-supporting structures for additive manufacturing, Addit. Manuf, 12(Part A), p. 60-70, 2016.
[5]. Jia J., Sun X., Structural Optimization Design of a Six Degrees of Freedom Serial Robot with Integrated Topology and Dimensional Parameters, Sensors, 23(16), p. 7183, 2023.
[6]. Chen J., Chen Q., Yang H., Additive manufacturing of a continuum topology-optimized palletizing manipulator arm, Mech. Sci, 12, p. 289-304, 2021.
[7]. Dammer G., et al., Design, topology optimization, and additive manufacturing of a pneumatically actuated lightweight robot, Actuators, 12(7), p. 266, 2023.
[8]. El Khadiri I., et al., Topology optimization methods for additive manufacturing: A review, Int. J. Simul. Multidisci. Des. Optim, 14, p. 12, 2023.
[9]. Fernandez E., et al., Topology optimisation for large-scale additive manufacturing: generating designs tailored to the deposition nozzle size, Virtual Phys. Prototyping, 16(2), p. 196-220, 2021.
[10]. Pinskier J., et al., Automated design of pneumatic soft grippers through design-dependent multi-material topology optimization, Proc. IEEE Int. Conf. Soft Robotics (RoboSoft), 2023.
[11]. Silva G. A., Beck A. T., Sigmund O., Stress-constrained topology optimization considering uniform manufacturing uncertainties, Comput. Methods Appl. Mech. Eng, 344, p. 512-537, 2019.
[12]. Suresh S., et al., Topology optimization for transversely isotropic materials with high-cycle fatigue as a constraint, Struct. Multidiscip. Optim, 63, p. 161-172, 2021.
[13]. Sigmund O., Maute K., Topology optimization approaches: A comparative review, Structural and Multidisciplinary Optimization, 48(6), p. 1031-1055, 2013.
[14]. Suresh S., et al., Topology optimization using a continuoustime high-cycle fatigue model, Struct. Multidiscip. Optim, 61, p. 1011-1025, 2020.
[15]. Liu K., Tovar A., An efficient 3D topology optimization code written in Matlab, Structural and Multidisciplinary Optimization, 50(6) p. 1175-1196, 2014.
[16]. Oh M. K., Lee D. S., Yoo J., Stress-constrained topology optimization simultaneously considering the uncertainty of load positions, International Journal for Numerical Methods in Engineering, 123(3), p. 339-365, 2022.
[17]. Granlund G., et al., Stress-constrained topology optimization of structures subjected to non-proportional loading, Int. J. Numer. Methods Eng, 124(12), p. 2818-2836, 2023.
[18]. Kranz M., Lüdeker J. K., Kriegesmann B., A generalized approach for robust topology optimization using the first-order second-moment method for arbitrary response functions, Structural and Multidisciplinary Optimization, 66, 98, 2023.
[19]. Murat F., Kaymaz I., Şensoy A. T., Reliability-Based Topology Optimization Considering Overhang Constraints for Additive Manufacturing Design, Applied Sciences, 15(11), 6250, 2025.
[20]. Martínez-Frutos J., Herrero-Pérez D., Robust topology optimization of continuum structures, Computers & Structures, 257, 106677, p. 1-15, 2021.
[21]. Yun G. H., Topology optimization considering the fatigue constraint of variable amplitude load based on the equivalent static load approach, Appl. Math. Model, 56, p. 626-647, 2018.
[22]. Hermansen S. M., Lund E., Multi-material and thickness optimization of laminated composite structures subject to highcycle fatigue, Struct. Multidisc. Optim, 66, p. 259, 2023.
[23]. Tang H., et al., Numerical Prediction of Fatigue Life for Landing Gear Considering the Shock Absorber Travel, Aerospace, 12(1), p. 42, 2025.
[24]. Senhora F. V., Topology optimization with local stress constraints and continuously varying load direction, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 478(2260), 20220436, 2023.
[25]. Venkatesh S., et al., A review on aluminium 7075 alloy: Micro structure, mechanical properties and application, AIP Conf. Proc, 3221, p. 020001, 2024.
Published
2025-12-15
How to Cite
1.
MARIN FB, BURUIANĂ DL, IONICĂ L, MARIN M. Topology Optimization for Mass Reduction of a Structural Component in a Surgical Robotic Arm. The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science [Internet]. 15Dec.2025 [cited 18Dec.2025];48(4):51-6. Available from: https://gup.ugal.ro/ugaljournals/index.php/mms/article/view/9533
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