Continuum-based design of selectively compliant mechanisms taking into account large deformations
Final Report Abstract
There are intensive research efforts to develop topology optimization-based synthesis methods for compliant mechanisms (CM), which - analogous to conventional mechanisms - are specifically designed to realize a desired kinematics or desired deformations. Simplifying linear assumptions (small distortions and linear-elastic material behavior) are often made. Even in this case, the design of CM is challenging, as their deformation is dependent on applied loads (hereinafter referred to as transverse loads). If in practice other load cases are applied than those considered in the synthesis, it may no longer be possible to ensure the desired deformations. This problem was successfully solved with the participation of the applicant through the development of modal approaches that enable synthesis independent of transverse load. CM that generate a deformation that is almost independent of the transverse load are referred to as CM with selective compliance. In the course of the first funding period, a new, more robust modal approach was developed. The new modal approach can design CM whose kinematics approximate those of conventional mechanisms with mobility 1 and higher (hereafter referred to as pseudo-mobility). However, the approach is based on linear assumptions. In practice, CM are subject to large deformations, which is why the linear assumptions are not sufficient and non-linearities (in particular large distortions, also known as geometric non-linearity) must always be considered. For this reason, the modal approach was extended to nonlinear assumptions during the second funding period. The non-linear CM designed are intended to be path-generating CM. For these, a desired deformation path between the initial and final state is optimized, which can be precisely controlled. These extensions provide a powerful tool that enables the synthesis of complex CM.
Publications
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Synthesis of shape-adaptive plain bearings. Advances in Engineering Materials, Structures and Systems: Innovations, Mechanics and Applications, 1039-1043. CRC Press.
Kirmse, S.; Prase, B. & Hasse, A.
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Accuracy and precision: A new view on kinematic assessment of solid-state hinges and compliant mechanisms. Journal of Intelligent Material Systems and Structures, 33(13), 1743-1748.
Campanile, Lucio Flavio; Kirmse, Stephanie & Hasse, Alexander
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Synthesis of compliant mechanisms with selective compliance – An advanced procedure. Mechanism and Machine Theory, 157, 104184.
Kirmse, Stephanie; Campanile, Lucio Flavio & Hasse, Alexander
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Topology-optimization based design of multi-degree-of-freedom compliant mechanisms (mechanisms with multiple pseudo-mobility). Journal of Intelligent Material Systems and Structures, 34(5), 609-628.
Seltmann, Stephanie; Campanile, Lucio Flavio & Hasse, Alexander
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Topology optimization of compliant mechanisms with distributed compliance (hinge-free compliant mechanisms) by using stiffness and adaptive volume constraints instead of stress constraints. Mechanism and Machine Theory, 180, 105133.
Seltmann, Stephanie & Hasse, Alexander
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Topologieoptimierung von pfadgenerierenden nachgiebigen Mechanismen mit selektiver Nachgiebigkeit und mehrfachem Pseudolaufgrad, Dissertation, Technische Universität, Chemnitz
S. Seltmann
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„Nonlinear synthesis of shape-adaptive compliant structures with selective compliance”, Konferenzbeitrag, in ECCOMAS CONGRESS 2024, 9th European Congress on Computational Methods in Applied Sciences and Engineering, 3-7 June 2024, Lisboa, Portugal, 2024
S. Seltmann & A. Hasse
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Nonlinear Synthesis of Compliant Mechanisms With Selective Compliance. International Journal for Numerical Methods in Engineering, 126(14).
Seltmann, Stephanie & Hasse, Alexander
