Viscoelasticity of Load-Bearing Soft Tissues: Constitutive Formulation, Numerical Integration, and Computational Implementation

2015 ◽  
pp. 108-135
Keyword(s):  
Numerical Integration ◽  
Soft Tissues ◽  
Load Bearing ◽  
Computational Implementation ◽  
Constitutive Formulation

scholarly journals On the biomechanical function of scaffolds for engineering load-bearing soft tissues

2010 ◽  
Vol 6 (7) ◽  
pp. 2365-2381 ◽  
Author(s):  
John A. Stella ◽  
Antonio D’Amore ◽  
William R. Wagner ◽  
Michael S. Sacks
Keyword(s):  
Soft Tissues ◽  
Load Bearing

scholarly journals Effect of fiber crosslinking on collagen-fiber reinforced collagen-chondroitin-6-sulfate materials for regenerating load-bearing soft tissues

2012 ◽  
Vol 101A (1) ◽  
pp. 176-184 ◽  
Author(s):  
J. H. Shepherd ◽  
S. Ghose ◽  
S. J. Kew ◽  
A. Moavenian ◽  
S. M. Best ◽  
...  
Keyword(s):  
Collagen Fiber ◽  
Soft Tissues ◽  
Fiber Reinforced ◽  
Load Bearing

scholarly journals Characterisation of Skin Biomechanical Properties via Experiment-Numerical Integration

2018 ◽  
Vol 7 (4.26) ◽  
pp. 205
Author(s):  
Nor Fazli Adull Manan ◽  
Linasuriani Muhamad ◽  
Zurri Adam Mohd Adnan ◽  
Mohd Azman Yahaya ◽  
Jamaluddin Mahmud
Keyword(s):  
Mechanical Properties ◽  
Constitutive Equation ◽  
Numerical Integration ◽  
Soft Tissues ◽  
Biomechanical Properties ◽  
Test Machine ◽  
Medical Sciences ◽  
Ogden Model ◽  
Hyperelastic Model ◽  
Load Displacement

By having specific mechanical properties of skin, computational program and analysis become more reliable by showing the real skin behaviour. Up to date, mechanical properties of biological soft tissues (skin) haven’t been accepted solely for official usage. Therefore, characterisation of the skin biomechanical properties might contribute a new knowledge to the engineering and medical sciences societies. This paper highlights the success in characterising the hyperelastic parameters of leporine (rabbit) skin via experimental-numerical integration. A set of five sample of leporine skin were stretched using the conventional tensile test machine to generate the load-displacement graphs. Based on the Ogden’s constitutive equation and Mooney-Rivlin hyperelastic model, a stress-stretch equation was developed and a programme was written using Matlab. By varying the Ogden’s and Mooney-Rivlin’s parameters, the programme was capable of plotting stress-stretch and load-displacement graphs. The graphs that best match the experimental results will constitut to the corresponding coefficient, µ, and α for Ogden Model and C1 and C2 material parameter for Mooney-Rivlin Model that will best describe the behaviour of the leporine skin. The current results show that the Ogden’s coefficient and exponent for the subject was estimated to be (μ = 0.048MPa, α = 7.073) & (μ = 0.020MPa, α = 9.249) for Anterior-Posterior (AP) and Dorsal-Ventral (DV) respectively for Ogden Model. Meanwhile the value for Mooney-Rivlin Model were estimated to be (C1 = 1.271, C2 = 1.868) & (C1 = 1.128, C2 = 1.537) for AP and DV respectively, which is in close agreement to results found by other researchers. Further analyses for comparison could be carried out by developing mathematical model based on other constitutive equation such as Arruda-Boyce and Neo-Hookean. Nevertheless, this study has contributed to the knowledge about skin behaviour and the results are useful for references.  

Generalized Anisotropic Inverse Mechanics: Mechanical Anisotropy Correlates With Structural Anisotropy in Collagen Based Tissue Equivalents

2010 ◽  
Author(s):  
Ramesh Raghupathy ◽  
Spencer P. Lake ◽  
Edward A. Sander ◽  
Victor H. Barocas
Keyword(s):  
Blood Vessels ◽  
Soft Tissues ◽  
Mechanical Anisotropy ◽  
Underlying Structure ◽  
Test Case ◽  
Inhomogeneous Materials ◽  
Structural Anisotropy ◽  
Fiber Alignment ◽  
Load Bearing ◽  
Tissue Equivalents

Few elastographic methods handle both anisotropy and inhomogeneity. Much of the focus has been on inhomogeneous materials that are locally isotropic. However, most load-bearing tissues (heart, ligament, blood vessels) are highly anisotropic, and the underlying structure is distinct and essential for function. With disease or damage, this structure is altered, and hence the potential for an elastographic tool that identifies regional changes in anisotropy is high. In this study we present a generalized anisotropic inverse mechanics (GAIM) method that is applicable to soft tissues and demonstrate its performance on tissue equivalents which serve as a convenient test case due to their inhomogeneity and the ease of pre-specifying the fiber alignment pattern.

Constitutive Formulation for Numerical Analysis of Visco-Hyperelastic Damage Phenomena in Soft Biological Tissues

2006 ◽  
Author(s):  
Arturo N. Natali ◽  
Emanuele L. Carniel ◽  
Piero G. Pavan ◽  
Alessio Gasparetto ◽  
Franz G. Sander ◽  
...  
Keyword(s):  
Strain Rate ◽  
Soft Tissues ◽  
Mechanical Response ◽  
Constitutive Models ◽  
Experimental Tests ◽  
Biological Tissues ◽  
Tissue Response ◽  
Time Dependent ◽  
Soft Biological Tissues ◽  
Constitutive Formulation

Soft biological tissues show a strongly non linear and time-dependent mechanical response and undergo large strains under physiological loads. The microstructural arrangement determines specific anisotropic macroscopic properties that must be considered within a constitutive formulation. The characterization of the mechanical behaviour of soft tissues entails the definition of constitutive models capable of accounting for geometric and material non linearity. In the model presented here a hyperelastic anisotropic formulation is adopted as the basis for the development of constitutive models for soft tissues and can be properly arranged for the investigation of viscous and damage phenomena as well to interpret significant aspects pertaining to ordinary and degenerative conditions. Visco-hyperelastic models are used to analyze the time-dependent mechanical response, while elasto-damage models account for the stiffness and strength decrease that can develop under significant loading or degenerative conditions. Experimental testing points out that damage response is affected by the strain rate associated with loading, showing a decrease in the damage limits as the strain rate increases. This phenomena can be investigated by means of a model capable of accounting for damage phenomena in relation to viscous effects. The visco-hyperelastic damage model developed is defined on the basis of a Helmholtz free energy function depending on the strain-damage history. In particular, a specific damage criterion is formulated in order to evaluate the influence of the strain rate on damage. The model can be implemented in a general purpose finite element code. This makes it possible to perform numerical analyses of the mechanical response considering time-dependent effects and damage phenomena. The experimental tests develop investigated tissue response for different strain rate conditions, accounting for stretch situations capable of inducing damage phenomena. The reliability of the formulation is evaluated by a comparison with the results of experimental tests performed on pig periodontal ligament.

How can genipin assist gelatin/carbohydrate chitosan scaffolds to act as replacements of load-bearing soft tissues?

2013 ◽  
Vol 93 (2) ◽  
pp. 635-643 ◽  
Author(s):  
Melika Sarem ◽  
Fathollah Moztarzadeh ◽  
Masoud Mozafari
Keyword(s):  
Soft Tissues ◽  
Load Bearing ◽  
Chitosan Scaffolds

scholarly journals Corrosion and bone healing of Mg-Y-Zn-Zr-Ca alloy implants: Comparative in vivo study in a non-immobilized rat femoral fracture model

2019 ◽  
Vol 33 (9) ◽  
pp. 1178-1194 ◽  
Author(s):  
Da-Tren Chou ◽  
Daeho Hong ◽  
Sinan Oksuz ◽  
Riccardo Schweizer ◽  
Abhijit Roy ◽  
...  
Keyword(s):  
Bone Healing ◽  
Soft Tissues ◽  
High Stress ◽  
Fracture Site ◽  
Long Bone ◽  
Surgical Removal ◽  
Biochemical Tests ◽  
Load Bearing ◽  
Osteoblast Activity

Biodegradable magnesium (Mg) alloys exhibit improved mechanical properties compared to degradable polymers while degrading in vivo circumventing the complications of permanent metals, obviating the need for surgical removal. This study investigated the safety and efficacy of Mg-Y-Zn-Zr-Ca (WZ42) alloy compared to non-degradable Ti6Al4V over a 14-week follow-up implanted as pins to fix a full osteotomy in rat femurs and as wires wrapped around the outside of the femurs as a cerclage. We used a fully load bearing model allowing implants to intentionally experience realistic loads without immobilization. To assess systemic toxicity, blood cell count and serum biochemical tests were performed. Livers and kidneys were harvested to observe any accumulation of alloying elements. Hard and soft tissues adjacent to the fracture site were also histologically examined. Degradation behavior and bone morphology were determined using micro-computed tomography scans. Corrosion occurred gradually, with degradation seen after two weeks of implantation with points of high stress observed near the fracture site ultimately resulting in WZ42 alloy pin fracture. At 14 weeks however, normal bone healing was observed in femurs fixed with the WZ42 alloy confirmed by the presence of osteoid, osteoblast activity, and new bone formation. Blood testing exhibited no significant changes arising from the WZ42 alloy compared to the two control groups. No recognizable differences in the morphology and more importantly, no accumulation of Mg, Zn, and Ca in the kidney and liver of rats were observed. These load bearing model results collectively taken, thus demonstrate the feasibility for use of the Mg-Y-Zn-Zr-Ca alloy for long bone fracture fixation applications.

Growth and remodeling of load-bearing biological soft tissues

Meccanica ◽  
2016 ◽  
Vol 52 (3) ◽  
pp. 645-664 ◽  
Author(s):  
C. J. Cyron ◽  
J. D. Humphrey
Keyword(s):  
Soft Tissues ◽  
Growth And Remodeling ◽  
Load Bearing
Sign in / Sign up

Export Citation Format

Share Document