Quantifying mechanical properties in a murine fracture healing system using inverse modeling: preliminary work

2010 ◽  
Author(s):  
Michael I. Miga ◽  
Jared A. Weis ◽  
Froilan Granero-Molto ◽  
Anna Spagnoli
Keyword(s):  
Mechanical Properties ◽  
Fracture Healing ◽  
Inverse Modeling ◽  
Healing System ◽  
Preliminary Work

Determination of mechanical properties of the weld line by combining micro-indentation with inverse modeling

2014 ◽  
Vol 85 ◽  
pp. 347-362 ◽  
Author(s):  
Guangyong Sun ◽  
Fengxiang Xu ◽  
Guangyao Li ◽  
Xiaodong Huang ◽  
Qing Li
Keyword(s):  
Mechanical Properties ◽  
Inverse Modeling ◽  
Weld Line ◽  
Micro Indentation

scholarly journals Inhibition of GSK-3β Rescues the Impairments in Bone Formation and Mechanical Properties Associated with Fracture Healing in Osteoblast Selective Connexin 43 Deficient Mice

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e81399 ◽  
Author(s):  
Alayna E. Loiselle ◽  
Shane A. J. Lloyd ◽  
Emmanuel M. Paul ◽  
Gregory S. Lewis ◽  
Henry J. Donahue
Keyword(s):  
Mechanical Properties ◽  
Bone Formation ◽  
Fracture Healing ◽  
Connexin 43 ◽  
Gsk 3Β ◽  
Deficient Mice

Appropriate Objective Functions for Quantifying Iris Mechanical Properties Using Inverse Finite Element Modeling

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Anup D. Pant ◽  
Syril K. Dorairaj ◽  
Rouzbeh Amini
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Objective Function ◽  
Inverse Modeling ◽  
Measurement Errors ◽  
Ex Vivo ◽  
Treatment Strategies ◽  
Objective Functions ◽  
Estimation Of Parameters

Quantifying the mechanical properties of the iris is important, as it provides insight into the pathophysiology of glaucoma. Recent ex vivo studies have shown that the mechanical properties of the iris are different in glaucomatous eyes as compared to normal ones. Notwithstanding the importance of the ex vivo studies, such measurements are severely limited for diagnosis and preclude development of treatment strategies. With the advent of detailed imaging modalities, it is possible to determine the in vivo mechanical properties using inverse finite element (FE) modeling. An inverse modeling approach requires an appropriate objective function for reliable estimation of parameters. In the case of the iris, numerous measurements such as iris chord length (CL) and iris concavity (CV) are made routinely in clinical practice. In this study, we have evaluated five different objective functions chosen based on the iris biometrics (in the presence and absence of clinical measurement errors) to determine the appropriate criterion for inverse modeling. Our results showed that in the absence of experimental measurement error, a combination of iris CL and CV can be used as the objective function. However, with the addition of measurement errors, the objective functions that employ a large number of local displacement values provide more reliable outcomes.

scholarly journals Uncertainty quantification in subject-specific estimation of local vessel mechanical properties

2021 ◽  
Author(s):  
Bruno V Rego ◽  
Dar Weiss ◽  
Matthew R Bersi ◽  
Jay D Humphrey
Keyword(s):  
Mechanical Properties ◽  
Uncertainty Quantification ◽  
Inverse Modeling ◽  
Quantitative Estimation ◽  
Small Animal ◽  
Image Correlation ◽  
Model Parameters ◽  
Parameter Uncertainties ◽  
Local Point ◽  
Subject Specific

Quantitative estimation of local mechanical properties remains critically important in the ongoing effort to elucidate how blood vessels establish, maintain, or lose mechanical homeostasis. Recent advances based on panoramic digital image correlation (pDIC) have made high-fidelity 3D reconstructions of small-animal (e.g., murine) vessels possible when imaged in a variety of quasi-statically loaded configurations. While we have previously developed and validated inverse modeling approaches to translate pDIC-measured surface deformations into biomechanical metrics of interest, our workflow did not heretofore include a methodology to quantify uncertainties associated with local point estimates of mechanical properties. This limitation has compromised our ability to infer biomechanical properties on a subject-specific basis, such as whether stiffness differs significantly between multiple material locations on the same vessel or whether stiffness differs significantly between multiple vessels at a corresponding material location. In the present study, we have integrated a novel uncertainty quantification and propagation pipeline within our inverse modeling approach, relying on empirical and analytic Bayesian techniques. To demonstrate the approach, we present illustrative results for the ascending thoracic aorta from three mouse models, quantifying uncertainties in constitutive model parameters as well as circumferential and axial tangent stiffness. Our extended workflow not only allows parameter uncertainties to be systematically reported, but also facilitates both subject-specific and group-level statistical analyses of the mechanics of the vessel wall.

Disclosing the Mechanical Properties of Green Calcium-Silicate-Hydrates by Statistical Nanoindentation Techniques

2011 ◽  
Vol 409 ◽  
pp. 544-549 ◽  
Author(s):  
Luca Sorelli ◽  
Daniel Vallée ◽  
Aali R. Alizadeh ◽  
James Beaudoin ◽  
Nicholas Randall
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Statistical Analysis ◽  
Calcium Silicate ◽  
Layer Structure ◽  
Cement Industry ◽  
Stoichiometric Ratio ◽  
New Class ◽  
Preliminary Work ◽  
Calcium Silicate Hydrates

In order to reduce CO2emissions, the cement industry has developed a new class cements. The Calcium-Silicate-Hydrates (CSH) that form are generally characterized by a low stoichiometric ratio for CaO and SiO2. This low C/S ratio affects the C-S-H layer structure and has a significant effect on the mechanical properties. This work exploits a novel statistical nanoindentation technique (SNT) to study the effect of the C/S ratio on the mechanical properties of synthetic CSH. Different CSH types were prepared by varying the C/S ratio of the starting materials. After undertaking a grid nanoindentation approach for each sample, the statistical analysis allowed extracting the mechanical properties, such as elastic modulus, hardness and creep. The results of this preliminary work shed new light on the implications of C-S-H stoichiometry on mechanical properties.

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