Topology optimization of planar shape memory alloy thermal actuators using element connectivity parameterization

Langelaar, Matthijs; Yoon, Gil Ho; Kim, Y. Y.; Keulen, Fred van

doi:10.1002/nme.3199

Cited by 21 publications

(11 citation statements)

References 48 publications

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“…Figure briefly illustrates the realization of various mechanism components and joint conditions when two sets of variables take on their minimum or maximum values. The usefulness of the zero‐length springs in topology optimization was demonstrated in structure and mechanism design problems . A similar approach was also considered in .…”

Section: Modeling Analysis and Formulationmentioning

confidence: 99%

“…They suggested a nonlinear bar-based ground model and used both gradient and non-gradient optimizers. On the other hand, the spring-supported rigid-block model that employs rigid blocks and zero-length elastic springs [12][13][14] has been also suggested [6,9,15]. Interesting 266 S. I. KIM AND Y. Y. KIM alternative approaches have been also suggested by other researchers [7,8,10,11].…”

Section: Introductionmentioning

confidence: 99%

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Topology optimization of planar linkage mechanisms

Kim

2014

Int. J. Numer. Meth. Engng

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SUMMARYIn spite of increasing interest in gradient‐based topology optimization of linkage mechanisms, it is still difficult to solve practical, realistic problems. Besides the apparent difficulty resulting from high nonlinearity, the optimization problem faces other major difficulties: difficulty to satisfy the discrete DOF condition with continuous design variables and lack of intrinsic mechanisms to generate distinct black‐and‐white layouts. To deal with the DOF issue, we propose a new formulation, which maximizes a single objective function, the energy transmittance efficiency. It is shown that the efficiency function maximization handles DOF redundancy and deficiency simultaneously. To obtain distinct linkage layouts, a common practice is to introduce an artificial mass constraint and/or to remove unnecessary links during optimization. However, we do not use any artificial mass constraint but post‐process the optimized result to obtain the final layout by a special post‐processing algorithm. In this study, the linkage design model consists of nonlinear ground bars and zero‐length springs. The springs are used to fix bar‐connecting nodes to the ground, generating pinned joints. After verifying the effectiveness of the proposed approach for four‐bar linkage synthesis, we synthesize an automobile steering mechanism satisfying the Ackermann condition. The steering mechanism problem is solved here for the first time. Copyright © 2014 John Wiley & Sons, Ltd.

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Section: Modeling Analysis and Formulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Topology optimization of planar linkage mechanisms

Kim

2014

Int. J. Numer. Meth. Engng

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“…24,30 Although substantial work has been done to improve these design techniques, there remains relatively little research on topology optimization of SMAs-the most widely used active material. One previous study proposed an optimization approach for SMA structures focusing on pseudoelasticity, 31 however there remains no similar study on design for the TWSME. Since the phase transition behavior of SMAs varies significantly from one material to the other, SMA-based designs are the result of repeated testing and experimentation.…”

Section: Introductionmentioning

confidence: 99%

Thermomechanical topology optimization of shape‐memory alloy structures using a transient bilevel adjoint method

Kang

James

2020

Numerical Meth Engineering

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We present a novel method for computational design of adaptive shape-memory alloy (SMA) structures via topology optimization. By optimally distributing a SMA within the prescribed design domain, the proposed algorithm seeks to tailor the two-way shape-memory effect (TWSME) and pseudoelasticity response of the SMA materials. Using a phenomenological material model, the thermomechanical response of the SMA structure is solved through inelastic finite element analysis, while assuming a transient but spatially uniform temperature distribution. The material distribution is parameterized via a SIMP formulation, with gradient-based optimization used to perform the optimization search. We derive a transient, bilevel adjoint formulation for analytically computing the design sensitivities. We demonstrate the proposed design framework using a series of two-dimensional thermomechanical benchmark problems. These examples include design for optimal displacement due to the TWSME, and design for maximum mechanical advantage while accounting for pseudoelasticity. K E Y W O R D Scomputational inelasticity, pseudoelasticity, shape-memory alloys, topology optimization, transient adjoint sensitivity analysis, two-way shape-memory effects 1 2558

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“…Normally, these methods find a tradeoff between stiffness measures (e.g., compliance/strain energy) and flexibility measures (e.g., output displacements/mutual strain energy) of the compliant continua [14]. On the other hand, TO approaches involving large deformation with/without nonlinear constitutive models [15][16][17][18][19][20][21][22][23][24][25] are much less common. This could be mostly due to numerical difficulties in handling significantly large deformation characterized via geometrical and material nonlinearities and distortion/inversion of low-stiffness FEs.…”

Section: Introductionmentioning

confidence: 99%

Compliant Fluidic Control Structures: Concept and synthesis approach

Kumar

Fanzio

Sasso

et al. 2019

Computers & Structures

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The concept and synthesis approach for planar Compliant Fluidic Control Structures (CFCSs), monolithic flexible continua with embedded functional pores, is presented in this manuscript. Such structures are envisioned to find application in biomedicine as tunable microfluidic devices for drug/nutrient delivery. The functional pores enlarge and/or contract upon deformation of the compliant structure in response to external stimuli, facilitating the regulated control of fluid/nutrient/drug transport. A thickness design variable based topology optimization problem is formulated to generate effective designs of these structures. An objective based on hydraulic diameter(s) is conceptualized, and it is extremized using a gradient based optimizer. Both geometrical and material nonlinearities are considered. The nonlinear behaviour of employed hyperelastic material is modeled via the Arruda-Boyce constitutive material model. Large-displacement finite element analysis is performed using the updated Lagrangian formulation in plane-stress setting. The proposed synthesis approach is applied to various CFCSs for a variety of fluidic control functionalities. The optimized designs of various CFCSs with single and/or multiple functional pores are fabricated via a Polydimethylsiloxane (PDMS) soft lithography process, using a high precision 3D printed mold and their performances are compared with the numerical predictions.

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Topology optimization of planar shape memory alloy thermal actuators using element connectivity parameterization

Cited by 21 publications

References 48 publications

Topology optimization of planar linkage mechanisms

Topology optimization of planar linkage mechanisms

Thermomechanical topology optimization of shape‐memory alloy structures using a transient bilevel adjoint method

Compliant Fluidic Control Structures: Concept and synthesis approach

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