Optimization based synthesis of pelvic structure for loads in running gait cycle

Kumar, KES and Rakshit, S (2022) Optimization based synthesis of pelvic structure for loads in running gait cycle. In: Sadhana - Academy Proceedings in Engineering Sciences, 47 (3).

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Abstract

Pelvic bone is a complex and robust load-bearing skeletal structure in the human body, the evolution of which might have been influenced by mechanical loads of daily activities like walking, upright standing, and running. Since the main function of skeletal bones is to provide rigidity to the body and provide hard surfaces for muscle attachment as well, in this work we propose a compliance minimization problem to determine whether material distribution guided by topology optimization yields a skeletal structure similar to the pelvic bone under same boundary conditions and volumetric constraints. As bone growth occurs in response to the mechanical loads acting on it, we consider the maximal loads that the pelvic bone may experience for a continued period of time, namely during running. The running gait cycle is divided into seven phases, and the objective function is a weighted combination of these seven phases. The optimal geometries are compared with the natural hemi-pelvis by measuring shape similarity using Procrustes analysis. Results show that the optimal geometries have good shape similarity in stance phases. We also explore the design space by considering a combination of sequence of phases which is an alternative to the weighted multiple load-case objective function. In all cases, the optimal geometries are stiffer than the hip bone. To validate this result, we conducted compression test experiments on selected optimal geometries and natural hemi-pelvis model of same material and found that the experimental results prove that topology optimization based optimal geometries are indeed more stiff than the natural hemi-pelvis geometry.

Item Type:	Journal Article
Publication:	Sadhana - Academy Proceedings in Engineering Sciences
Publisher:	Springer
Additional Information:	The copyright for this article belongs to the Springer.
Keywords:	Biomechanics; multiple loads; OptiStruct®; procrustes analysis; topology optimization
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	04 Jul 2022 05:39
Last Modified:	04 Jul 2022 05:39
URI:	https://eprints.iisc.ac.in/id/eprint/74118

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