Pith. sign in

REVIEW 3 major objections 6 minor 2 cited by

Constitutive Kolmogorov-Arnold Networks (CKANs): Combining Accuracy and Interpretability in Data-Driven Material Modeling

T0 review · 3 major / 6 minor · reviewed 2026-08-08 · deepseek-v4-flash

Pith's one-line read Constitutive Kolmogorov–Arnold Networks turn stress-strain data into symbolic material laws without sacrificing accuracy or extrapolation.

desk verdict A genuinely useful KAN-based constitutive modeling framework with a strong same-material extrapolation demo, but the Ecoflex cross-material claim sits on a table with identical rows that needs an author explanation. read the letter →

arxiv 2502.05682 v2 pith:RVR4HJQ6 submitted 2025-02-08 physics.comp-ph cond-mat.mtrl-sci

classification physics.comp-phcond-mat.mtrl-sci MSC 74B2068T07
keywords Kolmogorov-ArnoldNetworksdata-drivenmechanicsphysics-informedmachinelearningConstitutiveArtificialNeuralsoftmaterialssymbolicregressioninterpretablehyperelasticity
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper claims that the long-standing trade-off between accuracy, interpretability, and extrapolation in data-driven material modeling can be removed by building Kolmogorov–Arnold Networks directly into a constitutive framework. The resulting Constitutive Kolmogorov–Arnold Networks (CKANs) learn a strain-energy function whose connection weights are univariate splines that, after sparsification, are converted one by one into compact symbolic expressions. On the classical vulcanized-rubber benchmark, a CKAN using a mixed invariant-and-stretch basis fits all three deformation modes with R² = 0.999 and, trained only on those data, predicts the independent general biaxial response of the same rubber. A separate CKAN trained on uniaxial Ecoflex data at three Shore hardness levels predicts the withheld fourth hardness level. If these results hold, hybrid constitutive modeling no longer has to choose between black-box flexibility and readable, transferable equations.

What carries the argument

The load-bearing object is the spline activation function inside a KAN layer. Instead of scalar weights, each connection is a cubic Hermite or B-spline curve with learnable control points, and partial monotonicity can be imposed per input. The CKAN arranges such activations so that their composition equals the strain energy $\Psi_{\mathrm{KAN}}$ over a chosen functional basis (principal stretches, principal invariants, modified invariants, or a mixed basis), differentiates $\Psi_{\mathrm{KAN}}$ to obtain stresses, and regularizes with L1 and entropy terms to force most activations to zero. The surviving activations are replaced by symbolic functions from a library, with affine parameters fit by constrained optimization, yielding a final closed-form strain energy. The separable Valanis–Landel ansatz with shared parameters is what keeps the principal-stretch version isotropic and tractable.

What would settle it

Compute stress-strain curves from a deliberately non-separable hyperelastic energy, such as $\Psi = \sum_\alpha f(\lambda_\alpha) + c(\lambda_1-1)(\lambda_2-1)$ with $c \neq 0$, train a principal-stretch CKAN on dense noiseless biaxial data, and check whether the loss can reach machine precision. If it cannot, the Valanis–Landel ansatz—not the data—is what limits the stretch-based CKAN.

Watch

Extended reading notes

Core claim

The central claim is that a strain-energy function can be learned as a Kolmogorov–Arnold Network—a network in which each connection is a trainable one-dimensional spline rather than a scalar weight—and then converted into a symbolic formula without losing accuracy. Objectivity, material symmetry, incompressibility, and a stress-free reference state are built into the architecture; principal-stretch variants enforce the Valanis–Landel additive separability $\Psi = \sum_\alpha \omega_1(\lambda_\alpha) + \sum_\alpha \omega_{-1}(\lambda_\alpha^{-1})$ through parameter sharing. Sparsification removes redundant activations during training, and symbolification fits each surviving spline to a small library of elementary functions with affine rescaling. The paper reports that the mixed basis reaches R² = 0.999 on the rubber benchmark and transfers to the general biaxial dataset, that principal-stretch CKANs best capture tension-compression asymmetry in brain tissue, and that feature-augmented CKANs interpolate and extrapolate Shore hardness in silicone. The authors argue this shows hybrid models can be simultaneously accurate, interpretable, and extrapolative.

Load-bearing premise

The stretch-based variant of the model can only represent strain energies that are sums of one-dimensional functions of the individual stretches; if a material's response depends on how stretches interact, this architecture cannot see it.

Editorial extensions

If this is right

  • The same pipeline can deliver both a fitted constitutive law and a symbolic equation, so downstream finite-element codes can use the closed form rather than the network.
  • Functional-basis choice is decisive: for multi-axial rubber, principal-stretch or mixed bases generalize far better than principal-invariant bases, which the paper ties to earlier evidence that the first two invariants alone under-describe vulcanized rubber.
  • Feature augmentation (e.g., Shore hardness) turns a CKAN into a predictor for unseen material variants, demonstrated by leave-one-out hardness prediction.
  • Sparsification plus monotonicity yields compact, physically sensible forms: the stretch-based CKAN recovers a classic power-law rubber energy, and invariant-based brain CKANs reduce to functions of the second invariant alone.
  • The framework is not limited to rubber: brain tissue data show it handles tension-compression asymmetry with sparse data, given the right functional basis.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The paper's own results suggest the strongest test of CKAN generality is a material whose true energy is not additively separable in stretches; for such materials the stretch-based variant would need a richer ansatz, and the mixed basis would carry the burden.
  • A natural next experiment is to let an attribution-based pruning score decide which activation to keep; the paper notes that pruning by magnitude alone can discard functions that matter for stress derivatives, so better attribution could improve sparsity without accuracy loss.
  • If symbolification can be made fully automatic—the paper flags manual hyperparameter and regression tuning as a limitation—CKANs become a drop-in tool for constitutive model discovery across soft materials, potentially replacing bespoke symbolic-regression pipelines.
  • The recovered Shore-hardness law, a hyperbolic cosine in the first invariant with a quadratic hardness term, suggests a testable constitutive ansatz for silicone elastomers that experimentalists could verify with independent data.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 6 minor

Summary. The manuscript introduces Constitutive Kolmogorov–Arnold Networks (CKANs), which represent hyperelastic strain energy functions using KANs with spline activations, enforce constitutive normalization and optional monotonicity, sparsify the network during training, and convert the remaining activations into symbolic expressions. The framework is compared across four functional bases on Treloar's rubber data, with Kawabata's biaxial data as a validation set, applied descriptively to human brain tissue, and used in a leave-one-out study on Ecoflex silicones of varying Shore hardness. The central claim is that CKANs simultaneously achieve accuracy, interpretability, and extrapolability, including the ability to predict the behavior of previously unseen materials.

Significance. The paper is a solid engineering contribution. The continuum mechanics derivations in Appendices A and C are careful and internally consistent, and the systematic comparison of four functional bases on the same benchmark data is informative. The authors report the discovered symbolic strain energy functions in tabular form, which aids reproducibility and interpretability. The feature-augmentation idea, using Shore hardness as an additional input, is promising if the predictive claims can be substantiated. If the Ecoflex results are validated, the CKAN framework would be a useful addition to the hybrid constitutive modeling toolbox. However, the strongest cross-material predictive claim rests on a single leave-one-out experiment whose reported parameter table contains an unexplained duplication, and this issue must be resolved before the claim can be accepted at face value.

major comments (3)
  1. [Table 2, Section 5.3] The rows for 'Leave out Shore OO-20' and 'Leave out Shore OO-30' are numerically identical to four significant figures in all six material parameters (a=6.4998, b=0.3427, c=0.4190, d=0.0100, e=0.0800, f=-0.6707). These two leave-one-out training sets differ, and independent optimizations on different datasets would not be expected to converge to exactly the same parameter values. This situation indicates either a transcription error in the table or a model that is insensitive to which hardness level is withheld; in the latter case, the claimed predictive capability for unseen Shore hardness levels would not be supported. Please re-run the two experiments, report the actual parameter sets and optimization seeds, and correct the table if needed.
  2. [Abstract, Section 5.1, Section 6] The Kawabata validation is a same-material, different-deformation-mode generalization test: as the paper states, Treloar and Kawabata used vulcanized rubber of the same chemical composition. The phrase 'predicting previously unseen materials' in the Abstract and Conclusions is therefore supported only by the Ecoflex experiment. Please qualify the extrapolation claim so that it is clear that the Treloar-to-Kawabata result demonstrates generalization to new deformation modes of a known material, not prediction for an unseen material.
  3. [Section 2.2, Eq. (13), Appendix B] The principal stretch-based CKAN and the mixed CKAN impose structural assumptions: the Valanis–Landel additive separability for the former and an additive invariant-plus-stretch split for the latter. Not every isotropic hyperelastic strain energy function is additively separable in this way, so these CKAN variants cannot represent non-separable coupling between stretches. This restriction is acknowledged in the derivation but should be stated explicitly as a limitation in Sections 3.2 and 6, because the abstract and conclusions claim a general resolution of the accuracy/interpretability trade-off without this caveat.
minor comments (6)
  1. [Section 4.1] The heading 'Sparsificaiton' contains a typo and should read 'Sparsification'.
  2. [Figure E.3] The figure titles repeat the typo 'Princiapl invariant-based'; this should be corrected to 'Principal invariant-based'.
  3. [Appendix C.1] The sentence 'For an isotropic incompressible material, the' is incomplete and should either be finished or removed.
  4. [Data availability] The manuscript does not include a data or code availability statement. Given that the numerical results are central to the claims, please provide a statement and, if possible, release code and data to reproduce the results, especially the Ecoflex leave-one-out study.
  5. [Figure 9a] The reported 'MSE = 0.0000' to four decimal places is not informative; please report the value with more significant digits or in scientific notation.
  6. [Section 5.3] The leave-one-out study uses only four hardness levels, and the reported R² and MSE values are single point estimates. Please state whether repeated training runs with different random seeds were performed and report the resulting variability, or at least note the absence of such a stability check more prominently.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity found: the CKAN's symbolic laws are fitted representations validated against external data, not reductions to their training inputs.

full rationale

The derivation chain is self-contained: CKAN's strain energy ΨCKAN (Eq. 21) is a fitting architecture whose spline parameters are optimized against stress data, and the symbolification step (Sec. 4.3) is an explicit post-processing compression of the fitted splines rather than a parameter-free derivation; the paper does not represent it differently. The central extrapolation claims are tested against data not used in fitting: Section 5.1 trains only on Treloar's uniaxial, equibiaxial, and pure shear data and validates on Kawabata's general biaxial set, and Section 5.3's leave-one-out Ecoflex analysis withholds entire Shore hardness levels, so the held-out curves are out-of-sample. No equation defines the target in terms of the quantity said to predict it; normalization terms Ψσ and Ψε are constraints, not predictions. Self-citations to CANN work appear only as background and conceptual lineage, while the load-bearing evidence is in-paper external benchmarks. One non-circular reproducibility concern is that Table 2 lists identical parameter tuples for the OO-20 and OO-30 leave-one-out folds although those folds have different training sets; this weakens the Ecoflex predictive demonstration but is an inconsistency, not a reduction of prediction to fit by construction.

Assumptions & free parameters 5 free parameters · 9 assumptions · 0 invented entities

The central claim rests on standard continuum mechanics assumptions and on architectural choices that restrict the class of representable strain energy functions. The discovered symbolic expressions' coefficients are fitted to data, and several hyperparameters (network topology, regularization strength, spline grid, symbolic library) are selected by hand without reported values.

free parameters (5)
  • Material parameters of discovered symbolic models = e.g., Treloar mixed basis: a=2.8333 MPa, b=7.6034e-4, c=4.9633e-3 MPa, d=0.0315, e=2.3312 MPa, f=0.0219
    These coefficients are optimized against stress data after symbolification; they are part of the fitted model output.
  • Regularization strength Λ = not reported
    Hyperparameter in Eq. (27) controlling sparsification; unspecified numerically.
  • Spline grid size and B-spline order = not reported
    KAN 1.0 default settings are used, but no grid size or spline order is given.
  • Symbolic function library B = elementary functions (monomials, ln, exp, cos, etc.)
    User-chosen library constrains the symbolic search space.
  • Network topologies N = e.g., [3,4,1], [3,1,1]
    Chosen per dataset; affects model capacity.
assumptions (9)
  • standard math Kolmogorov-Arnold representation theorem: any continuous multivariate function on [0,1]^n can be represented as a finite composition of univariate functions and sums
    Invoked in Section 3.1 to justify KANs as universal approximators.
  • domain assumption Existence of a strain energy function Ψ(F) with P = ∂Ψ/∂F (hyperelasticity)
    Fundamental assumption of hyperelasticity, Section 2.2, Eq. (6).
  • domain assumption Objectivity is ensured by expressing Ψ as a function of C = F^T F only
    Section 2.2, Eq. (7).
  • domain assumption Isotropic materials: Ψ is a scalar isotropic tensor function, expressible in functional bases of invariants or stretches
    Section 2.2, Eq. (9).
  • domain assumption Incompressibility (J=1) for rubber and brain tissue
    Used in all examples, Section 5; determines the third stretch and introduces hydrostatic pressure p.
  • domain assumption Additive separability (Valanis-Landel hypothesis) for principal stretch-based CKANs: Ψ = Σ ω1(λα) + Σ ω−1(λα−1)
    Section 3.2, Eq. (13) and Appendix B; this restricts the function class and is not universal.
  • domain assumption Plane stress assumption to determine the hydrostatic pressure p in biaxial and shear tests
    Appendix A.2, e.g., P33=0 in Eqs. (A.20), (A.23), (A.26), (A.31).
  • domain assumption Monotonicity of strain energy with respect to strain inputs (and Shore hardness for Ecoflex)
    Section 5.3 and Appendix D.2; imposed via MonoKAN constraints, physically motivated but a priori restriction.
  • domain assumption Treloar and Kawabata vulcanized rubbers have the same chemical composition, permitting cross-dataset validation
    Section 5.1, citing [56]; if false, the generalization test is weakened.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Constitutive Kolmogorov-Arnold Networks (CKANs): Combining Accuracy and Interpretability in Data-Driven Material Modeling." pith.science (2026). https://pith.science/paper/RVR4HJQ6

@misc{pith2026250205682,
  author       = {Pith},
  title        = {Pith review of: Constitutive Kolmogorov-Arnold Networks (CKANs): Combining Accuracy and Interpretability in Data-Driven Material Modeling},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/RVR4HJQ6}},
  note         = {Machine review of arXiv:2502.05682}
}
read the original abstract

Hybrid constitutive modeling integrates two complementary approaches for describing and predicting a material's mechanical behavior: purely data-driven black-box methods and physically constrained, theory-based models. While black-box methods offer high accuracy, they often lack interpretability and extrapolability. Conversely, physics-based models provide theoretical insight and generalizability but may not capture complex behaviors with the same accuracy. Traditionally, hybrid modeling has required a trade-off between these aspects. In this paper, we show how recent advances in symbolic machine learning, specifically Kolmogorov-Arnold Networks (KANs), help to overcome this limitation. We introduce Constitutive Kolmogorov-Arnold Networks (CKANs) as a new class of hybrid constitutive models. By incorporating a post-processing symbolification step, CKANs combine the predictive accuracy of data-driven models with the interpretability and extrapolation capabilities of symbolic expressions, bridging the gap between machine learning and physical modeling.

Figures

Figures reproduced from arXiv: 2502.05682 by the authors.

Figure 1
Figure 1. Constitutive Kolmogorov-Arnold Networks (CKANs). Given experimental stretch λ and stress P data and po￾tentially also non-mechanical data f (such as microstructural imaging data or information on materials processing), a CKAN learns the strain energy function Ψ of a hyperelastic material. It inherently satisfies essential mathematical or physical requirements, such as objectivity, symmetry properties, or thermodynam… view at source ↗
Figure 2
Figure 2. Representation of special planar modes of deformation of a thin incompressible membrane using three different functional bases: the complexity of the functional forms required to represent uniaxial tension, equibiaxial tension, and pure or simple shear vastly differs depending on whether one relies on representing them in terms of (a) principal stretches {λ1, λ2}, (b) principal invariants {I1, I2}, (c) modified inva… view at source ↗
Figure 3
Figure 3. Comparison of a Kolmogorov–Arnold Network (KAN) and a feedforward neural network (FFNN). A KAN (a) can be interpreted as a generalization of an FFNN (b) where the weights are no longer constants but nonlinear functions, typically spline functions of higher order, and where as a consequence the intra-neural (typically nonlinear) activation function σ is no longer needed. While in an FFNN the weights wl,j,i are adjust… view at source ↗
Figures from the paper (10 more)
Figure 4
Figure 4. Figure 4: Schematic overview of the Constitutive Kolmogorov–Arnold Network (CKAN) framework: The right Cauchy Green deformation tensor C and the feature vector f serve as input to the CKAN. Depending on the chosen functional basis F (principal stretches, principal invariants, mo…
Figure 5
Figure 5. Figure 5: Examples of Kolmogorov–Arnold Networks (KANs) representing the strain energy function ΨKAN, where the functional basis F = {I1, I2, I3} was chosen and reduced to the setting of an incompressible material so that I3 is no longer required as an explicit part of the input…
Figure 6
Figure 6. Figure 6: Comparison of the descriptive performance on Treloar’s data: Mean squared error (MSE) and coefficient of determination (R2 ) of each functional basis for predicting the stress component P11. For simplicity, we report in this section and the related appendices only Ψˆ K…
Figure 7
Figure 7. Figure 7: Comparison of the generalization performance on Kawabata’s data: Mean normalized mean squared error (MNMSE) of each functional basis for predicting the stress components P11 and P22 in the small and large stretch regimes of Kawabata’s data. shows its fitting results on…
Figure 8
Figure 8. Figure 8: Training and validation results for vulcanized rubber. (a) Fitting performance on Treloar’s data [51]. (b) Architecture of the final CKAN after training; unconnected nodes indicate pruned activation functions of the network. (c)– (f) Generalization performance of the m…
Figure 9
Figure 9. Figure 9: Descriptive performance of CKAN based on principal stretches for human brain (cortex) tissue [59]: (a) Performance of CKAN simultaneously fitted to uniaxial tension, compression, and simple shear data. (b) Resulting strain energy functions and material parameters. (c) …
Figure 10
Figure 10. Figure 10: Comparison of the descriptive performance on the brain tissue data. Mean squared error (MSE) and coefficient of determination (R2 ) of the symbolic strain energy functions for the human brain (cortex) each using a different functional basis. highlighting the pivotal r…
Figure 11
Figure 11. Figure 11: Comparison of the predictive performance on the Ecoflex silicone polymer data. Mean squared error (MSE) and coefficient of determination (R2 ) of the stress curves generated from the discovered symbolic principal invariant-based strain energy functions for Ecoflex sil…
Figure 12
Figure 12. Figure 12: Training results (descriptive performance) and validation results (predictive performance) for Ecoflex silicone polymer data from [54] for principal invariant-based symbolic CKANs applied in leave-one-out cross-validation scheme. The lines represent the model response…
Figure 13
Figure 13. Figure 13: CKAN architectures obtained during the leave-one-out cross-validation test for Ecoflex silicone polymer data. The red graphs illustrate the symbolic activation functions fi,j,k, and the red lines are the only remaining connections after the training. Unconnected nodes…

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Inelastic Constitutive Kolmogorov-Arnold Networks: A generalized framework for automated discovery of interpretable inelastic material models

    cond-mat.mtrl-sci 2026-02 conditional novelty 6.0 of 10

    iCKAN combines input-convex Kolmogorov-Arnold networks with a thermodynamic inelasticity framework to turn stress-strain data into symbolic elastic and inelastic potentials.

  2. Non-smooth optimization meets automated material model discovery

    cs.CE 2025-07 conditional novelty 4.0 of 10

    The paper demonstrates that coordinate descent, LARS-LASSO, ISTA, and a new pathwise ISTA solve the L1-regularized sparse-regression problems arising in automated hyperelastic material model discovery, recovering know...

Reference graph

Works this paper leans on

74 extracted references · 66 canonical work pages · cited by 2 Pith papers

  1. [1]

    Leslie R. G. Treloar. The Elasticity of a Network of Long-Chain Molecules. II.Rubber Chemistry and Technology, 17(2):296–302, 1944

  2. [2]

    Rivlin and D

    Ronald S. Rivlin and D. W. Saunders. Large elastic deformations of isotropic materials VII. Experiments on the deformation of rubber.Philosophical Transactions of the Royal Society of London. Series A, Math- ematical and Physical Sciences, 243(865):251–288, 1951

  3. [3]

    Ray W. Ogden. Large deformation isotropic elasticity – on the correlation of theory and experiment for incompressible rubberlike solids.Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 326(1567):565–584, 1972

  4. [4]

    Biomechanics - Mechanical Properties of Living Tissues

    Yuan-Cheng Fung. Biomechanics - Mechanical Properties of Living Tissues. Springer New York, New York, NY, 1981

  5. [5]

    Holzapfel, T

    Gerhard A. Holzapfel, T. Christian Gasser, and Ray W. Ogden. A new constitutive framework for arterial wall mechanics and a comparative study of material models.Journal of Elasticity, 61(1-3):1–48, 2000

  6. [6]

    Ehret and Mikhail Itskov

    Alexander E. Ehret and Mikhail Itskov. A polyconvex hyperelastic model for fiber-reinforced materials in application to soft tissues.Journal of Materials Science, 42(21):8853–8863, 2007

  7. [7]

    Data-driven computational mechanics

    Trenton Kirchdoerfer and Michael Ortiz. Data-driven computational mechanics. Computer Methods in Applied Mechanics and Engineering, 304:81–101, 2016

  8. [8]

    Data-driven fracture mechanics

    Pietro Carrara, Laura De Lorenzis, Laurent Stainier, and Michael Ortiz. Data-driven fracture mechanics. Computer Methods in Applied Mechanics and Engineering, 372, 2020. 35

Show all 74 references
  1. [9]

    Garrett, and Xiping Wu

    Jamshid Ghaboussi, James H. Garrett, and Xiping Wu. Knowledge-Based Modeling of Material Behavior with Neural Networks.Journal of Engineering Mechanics, 117(1):132–153, 1991

  2. [10]

    Youssef. M.A. Hashash, Sungmoon Jung, and Jamshid Ghaboussi. Numerical implementation of a neural network based material model in finite element analysis.International Journal for Numerical Methods in Engineering, 59(7):989–1005, 2004

  3. [11]

    Theodore Sussman and Klaus J. Bathe. A model of incompressible isotropic hyperelastic material behavior using spline interpolations of tension-compression test data. Communications in Numerical Methods in Engineering, 25(1):53–63, 2009

  4. [12]

    Extension of the Sussman-Bathe spline-based hyperelastic model to incompressible transversely isotropic materials.Computers and Structures, 122:13–26, 2013

    Marcos Latorre and Francisco Javier Montáns. Extension of the Sussman-Bathe spline-based hyperelastic model to incompressible transversely isotropic materials.Computers and Structures, 122:13–26, 2013

  5. [13]

    What-You-Prescribe-Is-What-You-Get orthotropic hyper- elasticity

    Marcos Latorre and Francisco Javier Montáns. What-You-Prescribe-Is-What-You-Get orthotropic hyper- elasticity. Computational Mechanics, 53(6):1279–1298, 2014

  6. [14]

    WYPIWYG hyperelasticity for isotropic, compressible materials

    José Crespo, Marcos Latorre, and Francisco Javier Montáns. WYPIWYG hyperelasticity for isotropic, compressible materials. Computational Mechanics, 59(1):73–92, 2017

  7. [15]

    Data-driven hyperelasticity, Part I: A canonical isotropic formulation for rubberlike materials.Journal of the Mechanics and Physics of Solids, 179:105381, 2023

    Hüsnü Dal, Funda Aksu Denli, Alp Kağan Açan, and Michael Kaliske. Data-driven hyperelasticity, Part I: A canonical isotropic formulation for rubberlike materials.Journal of the Mechanics and Physics of Solids, 179:105381, 2023

  8. [16]

    Versatile data-adaptive hyperelastic energy functions for soft materials.Computer Methods in Applied Mechanics and Engineering, 430:117208, 2024

    Simon Wiesheier, Miguel Angel Moreno-Mateos, and Paul Steinmann. Versatile data-adaptive hyperelastic energy functions for soft materials.Computer Methods in Applied Mechanics and Engineering, 430:117208, 2024

  9. [17]

    Goldberg et al

    Carey B. Goldberg et al. To do no harm—and the most good—with AI in health care.Nature Medicine, 30(3):623–627, 2024

  10. [18]

    Fuhg, Govinda Anantha Padmanabha, Nikolaos Bouklas, Bahador Bahmani, WaiChing Sun, Niko- laos N

    Jan N. Fuhg, Govinda Anantha Padmanabha, Nikolaos Bouklas, Bahador Bahmani, WaiChing Sun, Niko- laos N. Vlassis, Moritz Flaschel, Pietro Carrara, and Laura De Lorenzis. A review on data-driven consti- tutive laws for solids.Archives of Computational Methods in Engineering, pag...

  11. [19]

    Klein, Karl A

    Lennart Linden, Dominik K. Klein, Karl A. Kalina, Jörg Brummund, Oliver Weeger, and Markus Kästner. Neural networks meet hyperelasticity: A guide to enforcing physics.Journal of the Mechanics and Physics of Solids, 179:105363, 2023

  12. [20]

    Rausch, Francisco Sahli Costabal, and Adrian Buganza Tepole

    Vahidullah Taç, Manuel K. Rausch, Francisco Sahli Costabal, and Adrian Buganza Tepole. Data-driven anisotropic finite viscoelasticity using neural ordinary differential equations.Computer methods in applied mechanics and engineering, 411:116046, 2023

  13. [21]

    A mechanics-informed artificial neural network ap- proach in data-driven constitutive modeling.International Journal for Numerical Methods in Engineering, 123(12):2738–2759, 2022

    Faisal As’ ad, Philip Avery, and Charbel Farhat. A mechanics-informed artificial neural network ap- proach in data-driven constitutive modeling.International Journal for Numerical Methods in Engineering, 123(12):2738–2759, 2022

  14. [22]

    Abdolazizi, Roland C

    Kevin Linka, Markus Hillgärtner, Kian P. Abdolazizi, Roland C. Aydin, Mikhail Itskov, and Christian J. Cyron. Constitutive artificial neural networks: A fast and general approach to predictive data-driven constitutive modeling by deep learning.Journal of Computational Physics,...

  15. [23]

    Abdolazizi, Kevin Linka, and Christian J

    Kian P. Abdolazizi, Kevin Linka, and Christian J. Cyron. Viscoelastic constitutive artificial neural net- works (vCANNs) – A framework for data-driven anisotropic nonlinear finite viscoelasticity.Journal of Computational Physics, 499:112704, 2023

  16. [24]

    Humphrey, and Christian J

    Kevin Linka, Cristina Cavinato, Jay D. Humphrey, and Christian J. Cyron. Predicting and understanding arterial elasticity from key microstructural features by bidirectional deep learning.Acta Biomaterialia, 147:63–72, 2022

  17. [25]

    Unsupervised discovery of interpretable hyper- elastic constitutive laws.Computer Methods in Applied Mechanics and Engineering, 381:113852, 2021

    Moritz Flaschel, Siddhant Kumar, and Laura De Lorenzis. Unsupervised discovery of interpretable hyper- elastic constitutive laws.Computer Methods in Applied Mechanics and Engineering, 381:113852, 2021. 36

  18. [26]

    A new family of Constitutive Artificial Neural Networks towards automated model discovery

    Kevin Linka and Ellen Kuhl. A new family of Constitutive Artificial Neural Networks towards automated model discovery. Computer Methods in Applied Mechanics and Engineering, 403:115731, 2023

  19. [27]

    Theory and implemen- tation of inelastic constitutive artificial neural networks

    Hagen Holthusen, Lukas Lamm, Tim Brepols, Stefanie Reese, and Ellen Kuhl. Theory and implemen- tation of inelastic constitutive artificial neural networks. Computer Methods in Applied Mechanics and Engineering, 428:117063, 2024

  20. [28]

    S.t Pierre, Divya Rajasekharan, Ethan C

    Skyler R. S.t Pierre, Divya Rajasekharan, Ethan C. Darwin, Kevin Linka, Marc E. Levenston, and Ellen Kuhl. Discovering the mechanics of artificial and real meat.Computer Methods in Applied Mechanics and Engineering, 415:116236, 2023

  21. [29]

    McCulloch, Skyler R

    Jeremy A. McCulloch, Skyler R. St. Pierre, Kevin Linka, and Ellen Kuhl. On sparse regression, Lp- regularization, and automated model discovery.International Journal for Numerical Methods in Engineer- ing, 125(14):e7481, 2024

  22. [30]

    Automated model discovery for tensional homeostasis: Constitutive machine learning in growth and remodeling.Computers in Biology and Medicine, 186:109691, 2025

    Hagen Holthusen, Tim Brepols, Kevin Linka, and Ellen Kuhl. Automated model discovery for tensional homeostasis: Constitutive machine learning in growth and remodeling.Computers in Biology and Medicine, 186:109691, 2025

  23. [31]

    Symbolic regression in materials science.MRS Communications, 9(3):793–805, 2019

    Yiqun Wang, Nicholas Wagner, and James M Rondinelli. Symbolic regression in materials science.MRS Communications, 9(3):793–805, 2019

  24. [32]

    Automaticgenerationofinterpretablehypere- lastic material models by symbolic regression.International Journal for Numerical Methods in Engineering, 124(9):2093–2104, 2023

    RasulAbdusalamov, MarkusHillgärtner, andMikhailItskov. Automaticgenerationofinterpretablehypere- lastic material models by symbolic regression.International Journal for Numerical Methods in Engineering, 124(9):2093–2104, 2023

  25. [33]

    Hou, and Max Tegmark

    Ziming Liu, Yixuan Wang, Sachin Vaidya, Fabian Ruehle, James Halverson, Marin Soljačić, Thomas Y. Hou, and Max Tegmark. KAN: Kolmogorov-Arnold Networks.arXiv preprint arXiv:2404.19756, 2024

  26. [34]

    KAN 2.0: Kolmogorov- Arnold Networks Meet Science.arXiv preprint arXiv:2408.10205, 2024

    Ziming Liu, Pingchuan Ma, Yixuan Wang, Wojciech Matusik, and Max Tegmark. KAN 2.0: Kolmogorov- Arnold Networks Meet Science.arXiv preprint arXiv:2408.10205, 2024

  27. [35]

    Nonlinear solid mechanics: a continuum approach for engineering science

    Gerhard A Holzapfel. Nonlinear solid mechanics: a continuum approach for engineering science. John Wiley & Sons Ltd., 2000

  28. [36]

    Kearsley

    Elliot A. Kearsley. Note: Strain Invariants Expressed as Average Stretches.Journal of Rheology, 33(5):757– 760, 1989

  29. [37]

    Arruda and Mary C

    Ellen M. Arruda and Mary C. Boyce. A three-dimensional constitutive model for the large stretch behavior of rubber elastic materials.Journal of the Mechanics and Physics of Solids, 41(2):389–412, 1993

  30. [38]

    Springer Berlin Heidelberg, Berlin, Heidelberg, 1984

    Clifford Truesdell.The Elements of Continuum Mechanics. Springer Berlin Heidelberg, Berlin, Heidelberg, 1984

  31. [39]

    Ogden.Nonlinear Elastic Deformations

    Ray W. Ogden.Nonlinear Elastic Deformations. Dover Publications, 1997

  32. [40]

    Nonlinear material design using principal stretches

    Hongyi Xu, Funshing Sin, Yufeng Zhu, and Jernej Barbič. Nonlinear material design using principal stretches. ACM Transactions on Graphics, 34(4):1–11, 2015

  33. [41]

    Valanis and Robert F

    Kirk C. Valanis and Robert F. Landel. The Strain-Energy Function of a Hyperelastic Material in Terms of the Extension Ratios.Journal of Applied Physics, 38(7):2997–3002, 1967

  34. [42]

    Theoretical and numerical formulation of a molecular based constitutive tube-model of rubber elasticity.Computational and Theoretical Polymer Science, 7(3-4):227–241, 1997

    Gert Heinrich and Michael Kaliske. Theoretical and numerical formulation of a molecular based constitutive tube-model of rubber elasticity.Computational and Theoretical Polymer Science, 7(3-4):227–241, 1997

  35. [43]

    Mohd H.B.M. Shariff. Strain energy function for filled and unfilled rubberlike material.Rubber Chemistry and Technology, 73(1):1–18, 2000

  36. [44]

    Attard and Giles W

    Mario M. Attard and Giles W. Hunt. Hyperelastic constitutive modeling under finite strain.International Journal of Solids and Structures, 41(18-19):5327–5350, 2004. 37

  37. [45]

    Ehret and Alberto Stracuzzi

    Alexander E. Ehret and Alberto Stracuzzi. Variations on Ogden’s model: Close and distant relatives.Philo- sophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 380(2234), 2022

  38. [46]

    An extended tube-model for rubber elasticity: Statistical-mechanical theory and finite element implementation.Rubber Chemistry and Technology, 72(4):602–632, 1999

    Michael Kaliske and Gert Heinrich. An extended tube-model for rubber elasticity: Statistical-mechanical theory and finite element implementation.Rubber Chemistry and Technology, 72(4):602–632, 1999

  39. [47]

    A general constitutive model of soft elastomers.Journal of the Mechanics and Physics of Solids, 117:110–122, 2018

    Yuhai Xiang, Danming Zhong, Peng Wang, Guoyong Mao, Honghui Yu, and Shaoxing Qu. A general constitutive model of soft elastomers.Journal of the Mechanics and Physics of Solids, 117:110–122, 2018

  40. [48]

    Davidson and N

    Jacob D. Davidson and N. C. Goulbourne. A nonaffine network model for elastomers undergoing finite deformations. Journal of the Mechanics and Physics of Solids, 61(8):1784–1797, 2013

  41. [49]

    Tensor Algebra and Tensor Analysis for Engineers

    Mikhail Itskov. Tensor Algebra and Tensor Analysis for Engineers. Mathematical Engineering. Springer Cham, 2015

  42. [50]

    MonoKAN: Certified Monotonic Kolmogorov- Arnold Network.arXiv preprint arXiv:2409.11078, 2024

    Alejandro Polo-Molina, David Alfaya, and Jose Portela. MonoKAN: Certified Monotonic Kolmogorov- Arnold Network.arXiv preprint arXiv:2409.11078, 2024

  43. [51]

    Leslie R.G. Treloar. Stress-strain data for vulcanised rubber under various types of deformation.Transac- tions of the Faraday Society, 40:59–70, 1944

  44. [52]

    Tei, and Hiromichi Kawai

    Sueo Kawabata, Masatoshi Matsuda, K. Tei, and Hiromichi Kawai. Experimental Survey of the Strain Energy Density Function of Isoprene Rubber Vulcanizate.Macromolecules, 14(1):154–162, jan 1981

  45. [53]

    Holzapfel, and Ellen Kuhl

    Silvia Budday, Gerhard Sommer, Johannes Haybaeck, Paul Steinmann, Gerhard A. Holzapfel, and Ellen Kuhl. Rheological characterization of human brain tissue.Acta Biomaterialia, 60:315–329, 2017

  46. [54]

    Ecoflex polymer of different Shore hardnesses: Exper- imental investigations and constitutive modelling.Mechanics of Materials, 144:103366, 2020

    Zisheng Liao, Mokarram Hossain, and Xiaohu Yao. Ecoflex polymer of different Shore hardnesses: Exper- imental investigations and constitutive modelling.Mechanics of Materials, 144:103366, 2020

  47. [55]

    Hyperelastic models for rubber-like materials: Consistent tangent operators and suitability for Treloar’s data.Archive of Applied Mechanics, 82(9):1183– 1217, 2012

    Paul Steinmann, Mokarram Hossain, and Gunnar Possart. Hyperelastic models for rubber-like materials: Consistent tangent operators and suitability for Treloar’s data.Archive of Applied Mechanics, 82(9):1183– 1217, 2012

  48. [56]

    Comparison of hyperelastic models for rubber-like materials.Rubber Chemistry and Technology, 79(5):835–858, 2006

    Gilles Marckmann and Erwan Verron. Comparison of hyperelastic models for rubber-like materials.Rubber Chemistry and Technology, 79(5):835–858, 2006

  49. [57]

    Amores, José M

    Víctor J. Amores, José M. Benítez, and Francisco J. Montáns. Data-driven, structure-based hyperelastic manifolds: A macro-micro-macro approach to reverse-engineer the chain behavior and perform efficient simulations of polymers.Computers and Structures, 231:106209, 2020

  50. [58]

    Analytical network-averaging of the tube model: Rubber elasticity

    Vu Ngoc Khiêm and Mikhail Itskov. Analytical network-averaging of the tube model: Rubber elasticity. Journal of the Mechanics and Physics of Solids, 95:254–269, 2016

  51. [59]

    Kohnert, Melanie Bauer, Friedrich P

    Silvia Budday, Gerhard Sommer, Christoph Birkl, Christian Langkammer, Johannes Haybaeck, J. Kohnert, Melanie Bauer, Friedrich P. Paulsen, Paul Steinmann, Ellen Kuhl, and Gerhard A. Holzapfel. Mechanical characterization of human brain tissue.Acta Biomaterialia, 48:319–340, 2017

  52. [60]

    Angela Mihai, Silvia Budday, Gerhard A

    L. Angela Mihai, Silvia Budday, Gerhard A. Holzapfel, Ellen Kuhl, and Alain Goriely. A family of hy- perelastic models for human brain tissue. Journal of the Mechanics and Physics of Solids, 106:60–79, 2017

  53. [61]

    Modelling brain tissue elasticity with the Ogden model and an alternative family of constitutive models.Philosophical transactions

    Afshin Anssari-Benam, Michel Destrade, and Giuseppe Saccomandi. Modelling brain tissue elasticity with the Ogden model and an alternative family of constitutive models.Philosophical transactions. Series A, Mathematical, physical, and engineering sciences, 380(2234):20210325, 2022

  54. [62]

    I too I2: A new class of hyperelastic isotropic incompressible models based solely on the second invariant.Journal of the Mechanics and Physics of Solids, 188:105670, 2024

    Ellen Kuhl and Alain Goriely. I too I2: A new class of hyperelastic isotropic incompressible models based solely on the second invariant.Journal of the Mechanics and Physics of Solids, 188:105670, 2024

  55. [63]

    Hopf, Daniela Sibilio, Aldo Ferrari, Alexander E

    Laura Bernardi, Raoul. Hopf, Daniela Sibilio, Aldo Ferrari, Alexander E. Ehret, and Eduardo Mazza. On the cyclic deformation behavior, fracture properties and cytotoxicity of silicone-based elastomers for biomedical applications. Polymer Testing, 60:117–123, 2017. 38

  56. [64]

    Case, Edward L

    Jennifer C. Case, Edward L. White, and Rebecca K. Kramer. Soft material characterization for robotic applications. Soft Robotics, 2(2):80–87, 2015

  57. [65]

    Stretchable CNTs- Ecoflex Composite as Variable-Transmittance Skin for Ultrasensitive Strain Sensing.Advanced Materials Technologies, 3(12):1800248, 2018

    Yuting Jiang, Yang Wang, Yogendra Kumar Mishra, Rainer Adelung, and Ya Yang. Stretchable CNTs- Ecoflex Composite as Variable-Transmittance Skin for Ultrasensitive Strain Sensing.Advanced Materials Technologies, 3(12):1800248, 2018

  58. [66]

    Leonard Mullins and N. R. Tobin. Stress softening in rubber vulcanizates. Part I. Use of a strain ampli- fication factor to describe the elastic behavior of filler-reinforced vulcanized rubber.Journal of Applied Polymer Science, 9(9):2993–3009, 1965

  59. [67]

    Fatigue of soft fibrous tissues: Multi-scale mechanics and constitutive modeling.Acta Biomaterialia, 71:398–410, 2018

    Kevin Linka, Markus Hillgärtner, and Mikhail Itskov. Fatigue of soft fibrous tissues: Multi-scale mechanics and constitutive modeling.Acta Biomaterialia, 71:398–410, 2018

  60. [68]

    Kevin Linka, Sarah R. St. Pierre, and Ellen Kuhl. Automated model discovery for human brain using Constitutive Artificial Neural Networks.Acta Biomaterialia, 160:134–151, 2023

  61. [69]

    Brunton, Joshua L

    Steven L. Brunton, Joshua L. Proctor, and J. Nathan Kutz. Discovering governing equations from data by sparse identification of nonlinear dynamical systems.Proceedings of the national academy of sciences, 113(15):3932–3937, 2016

  62. [70]

    Brunton and J

    Steven L. Brunton and J. Nathan Kutz.Data-driven science and engineering: Machine learning, dynamical systems, and control. Cambridge University Press, 2022

  63. [71]

    Meta-learning in neural net- works: A survey.IEEE transactions on pattern analysis and machine intelligence, 44(9):5149–5169, 2021

    Timothy Hospedales, Antreas Antoniou, Paul Micaelli, and Amos Storkey. Meta-learning in neural net- works: A survey.IEEE transactions on pattern analysis and machine intelligence, 44(9):5149–5169, 2021

  64. [72]

    Kalina, Jörg Brummund, WaiChing Sun, and Markus Kästner

    Karl A. Kalina, Jörg Brummund, WaiChing Sun, and Markus Kästner. Neural networks meet anisotropic hyperelasticity: A framework based on generalized structure tensors and isotropic tensor functions.Com- puter Methods in Applied Mechanics and Engineering, 437:117725, 2025

  65. [73]

    Klein, Oliver Weeger, and Peter Betsch

    Marlon Franke, Dominik K. Klein, Oliver Weeger, and Peter Betsch. Advanced discretization techniques for hyperelasticphysics-augmentedneuralnetworks. Computer Methods in Applied Mechanics and Engineering, 416:116333, 2023

  66. [74]

    Fritsch and Ralph E

    Frederick N. Fritsch and Ralph E. Carlson. Monotone piecewise cubic interpolation.SIAM Journal on Numerical Analysis, 17(2):238–246, 1980. 39

Pith tools

Reviewed August 8, 2026 · model on record in the stance chip above.