Poisson׳s ratio of arterial wall – Inconsistency of constitutive models with experimental data

Inflation and extension tests of arteries are essential for the understanding of arterial wall mechanics. Data for such tests of human arteries are rare. At autopsy we harvested 10 non-diseased external iliac arteries of aged subjects (52–87 yrs). Structural homogeneity was ensured by means of ultrasound imaging, and anamneses of patients were recorded. We measured the axial in situ stretches, load-free geometries and opening angles. Passive biaxial mechanical responses of preconditioned cylindrical specimens were studied in 37°C calcium-free Tyrode solution under quasistatic loading conditions. Specimens were subjected to pressure cycles varying from 0 to 33.3kPa (250mmHg) at nine fixed axial loads, varying from 0 to 9.90N. For the description of the load-deformation behavior we employed five “two-dimensional” orthotropic strain-energy functions frequently used in arterial wall mechanics. The associated constitutive models were compared in regard to their ability of representing the experimental data. Histology showed that the arteries were of the muscular type. In contrast to animal arteries they exhibited intimal layers of considerable thickness. The average ratio of wall thickness to outer diameter was 7.7, which is much less than observed for common animal arteries. We found a clear correlation between age and the axial in situ stretch λis(r=−0.72,P=0.03), and between age and distensibility of specimens, i.e. aged specimens are less distensible. Axial in situ stretches were clearly smaller (1.07±0.09,mean±SD) than in animal arteries. For one specimen λis was even smaller than 1.0, i.e. the vessel elongated axially upon excision. The nonlinear and anisotropic load-deformation behavior showed small hystereses. For the majority of specimens we observed axial stretches smaller than 1.3 and circumferential stretches smaller than 1.1 for the investigated loading range. Data from in situ inflation tests showed a significant increase of the axial stretch with intraluminal pressure. Thus, for this type of artery the axial in situ stretch of a non-pressurized vessel is not representative of the axial in vivo stretch. None of the constitutive models were able to represent the deformation behavior of the entire loading range. For the physiological loading range, however, some of the models achieved good agreement with the experimental data.

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Ability of Constitutive Models to Characterize the Temperature Dependence of Rubber Hyperelasticity and to Predict the Stress-Strain Behavior of Filled Rubber under Different Defor Mation States

Polymers ◽

10.3390/polym13030369 ◽

2021 ◽

Vol 13 (3) ◽

pp. 369

Author(s):

Xintao Fu ◽

Zepeng Wang ◽

Lianxiang Ma

Keyword(s):

Experimental Data ◽

Temperature Dependence ◽

Mechanical Response ◽

Constitutive Models ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Chain Model ◽

Stress Strain ◽

Filled Rubber ◽

Yeoh Model

In this paper, some representative hyperelastic constitutive models of rubber materials were reviewed from the perspectives of molecular chain network statistical mechanics and continuum mechanics. Based on the advantages of existing models, an improved constitutive model was developed, and the stress–strain relationship was derived. Uniaxial tensile tests were performed on two types of filled tire compounds at different temperatures. The physical phenomena related to rubber deformation were analyzed, and the temperature dependence of the mechanical behavior of filled rubber in a larger deformation range (150% strain) was revealed from multiple angles. Based on the experimental data, the ability of several models to describe the stress–strain mechanical response of carbon black filled compound was studied, and the application limitations of some constitutive models were revealed. Combined with the experimental data, the ability of Yeoh model, Ogden model (n = 3), and improved eight-chain model to characterize the temperature dependence was studied, and the laws of temperature dependence of their parameters were revealed. By fitting the uniaxial tensile test data and comparing it with the Yeoh model, the improved eight-chain model was proved to have a better ability to predict the hyperelastic behavior of rubber materials under different deformation states. Finally, the improved eight-chain model was successfully applied to finite element analysis (FEA) and compared with the experimental data. It was found that the improved eight-chain model can accurately describe the stress–strain characteristics of filled rubber.

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Three-Dimensional Stress Distribution in Arteries

Journal of Biomechanical Engineering ◽

10.1115/1.3138417 ◽

1983 ◽

Vol 105 (3) ◽

pp. 268-274 ◽

Cited By ~ 264

Author(s):

C. J. Chuong ◽

Y. C. Fung

Keyword(s):

Experimental Data ◽

Stress Distribution ◽

Vessel Wall ◽

Strain Energy ◽

Arterial Wall ◽

Three Dimensional ◽

Strain Energy Function ◽

Exponential Form ◽

Strain Relationship ◽

Longitudinal Stretch

A three-dimensional stress-strain relationship derived from a strain energy function of the exponential form is proposed for the arterial wall. The material constants are identified from experimental data on rabbit arteries subjected to inflation and longitudinal stretch in the physiological range. The objectives are: 1) to show that such a procedure is feasible and practical, and 2) to call attention to the very large variations in stresses and strains across the vessel wall under the assumptions that the tissue is incompressible and stress-free when all external load is removed.

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Experimental and Numerical Investigations on Hot Deformation Behavior and Processing Maps for ASS 304 and ASS 316

High Temperature Materials and Processes ◽

10.1515/htmp-2017-0047 ◽

2018 ◽

Vol 37 (9-10) ◽

pp. 873-888 ◽

Cited By ~ 3

Author(s):

Nitin Kotkunde ◽

Hansoge Nitin Krishnamurthy ◽

Swadesh Kumar Singh ◽

Gangadhar Jella

Keyword(s):

Experimental Data ◽

Strain Rate ◽

Hot Deformation ◽

Deformation Behavior ◽

Constitutive Models ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Processing Maps ◽

Hot Deformation Behavior ◽

Statistical Measures

AbstractA thorough understanding of hot deformation behavior plays a vital role in determining process parameters of hot working processes. Firstly, uniaxial tensile tests have been performed in the temperature ranges of 150 °C–600 °C and strain rate ranges of 0.0001–0.01s−1 for analyzing the deformation behavior of ASS 304 and ASS 316. The phenomenological-based constitutive models namely modified Fields–Backofen (m-FB) and Khan–Huang–Liang (KHL) have been developed. The prediction capability of these models has been verified with experimental data using various statistical measures. Analysis of statistical measures revealed KHL model has good agreement with experimental flow stress data. Through the flow stresses behavior, the processing maps are established and analyzed according to the dynamic materials model (DMM). In the processing map, the variation of the efficiency of the power dissipation is plotted as a function of temperature and strain rate. The processing maps results have been validated with experimental data.

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Model of geometrical and smooth muscle tone adaptation of carotid artery subject to step change in pressure

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2001.280.6.h2752 ◽

2001 ◽

Vol 280 (6) ◽

pp. H2752-H2760 ◽

Cited By ~ 38

Author(s):

P. Fridez ◽

A. Rachev ◽

J.-J. Meister ◽

K. Hayashi ◽

N. Stergiopulos

Keyword(s):

Experimental Data ◽

Smooth Muscle ◽

Theoretical Model ◽

Arterial Wall ◽

Circumferential Stress ◽

Experimental Studies ◽

Synthetic Activity ◽

Wall Thickening ◽

Model Parameters ◽

Induced Hypertension

Recent experimental studies have shown significant alterations of the vascular smooth muscle (VSM) tone when an artery is subjected to an elevation in pressure. Therefore, the VSM participates in the adaptation process not only by means of its synthetic activity (fibronectins and collagen) or proliferative activity (hypertrophy and hyperplasia) but also by adjusting its contractile properties and its tone level. In previous theoretical models describing the time evolution of the arterial wall adaptation in response to induced hypertension, the contribution of VSM tone has been neglected. In this study, we propose a new biomechanical model for the wall adaptation to induced hypertension, including changes in VSM tone. On the basis of Hill's model, total circumferential stress is separated into its passive and active components, the active part being the stress developed by the VSM. Adaptation rate equations describe the geometrical adaptation (wall thickening) and the adaptation of active stress (VSM tone). The evolution curves that are derived from the theoretical model fit well the experimental data describing the adaptation of the rat common carotid subjected to a step increase in pressure. This leads to the identification of the model parameters and time constants by characterizing the rapidity of the adaptation processes. The agreement between the results of this simple theoretical model and the experimental data suggests that the theoretical approach used here may appropriately account for the biomechanics underlying the arterial wall adaptation.

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Temperature Effect on the Compressive Behavior and Constitutive Model of Plain Hardened Concrete

Materials ◽

10.3390/ma13122801 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2801 ◽

Cited By ~ 2

Author(s):

Ayman El-Zohairy ◽

Hunter Hammontree ◽

Eddie Oh ◽

Perry Moler

Keyword(s):

Experimental Data ◽

Compressive Strength ◽

Temperature Effect ◽

Modulus Of Elasticity ◽

Constitutive Models ◽

Ultimate Strain ◽

Effect Of Temperature ◽

Hardened Concrete ◽

Compressive Behavior ◽

Stress Strain

Concrete is one of the most common and versatile construction materials and has been used under a wide range of environmental conditions. Temperature is one of them, which significantly affects the performance of concrete, and therefore, a careful evaluation of the effect of temperature on concrete cannot be overemphasized. In this study, an overview of the temperature effect on the compressive behavior of plain hardened concrete is experimentally provided. Concrete cylinders were prepared, cured, and stored under different temperature conditions to be tested under compression. The stress–strain curve, mode of failure, compressive strength, ultimate strain, and modulus of elasticity of concrete were evaluated between the ages of 7 and 90 days. The experimental results were used to propose constitutive models to predict the mechanical properties of concrete under the effect of temperature. Moreover, previous constitutive models were examined to capture the stress–strain relationships of concrete under the effect of temperature. Based on the experimental data and the proposed models, concrete lost 10–20% of its original compressive strength when heated to 100 °C and 30–40% at 260 °C. The previous constitutive models for stress–strain relationships of concrete at normal temperatures can be used to capture these relationships under the effect of temperature by using the compressive strength, ultimate strain, and modulus of elasticity affected by temperature. The effect of temperature on the modulus of elasticity of concrete was considered in the ACI 318-14 equation by using the compressive strength affected by temperature and the results showed good agreement with the experimental data.

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A Comparative Study on Johnson Cook, Modified Zerilli–Armstrong, and Arrhenius-Type Constitutive Models to Predict Compression Flow Behavior of SnSbCu Alloy

Materials ◽

10.3390/ma12101726 ◽

2019 ◽

Vol 12 (10) ◽

pp. 1726 ◽

Cited By ~ 5

Author(s):

Tongyang Li ◽

Bin Zhao ◽

Xiqun Lu ◽

Hanzhang Xu ◽

Dequan Zou

Keyword(s):

Experimental Data ◽

Flow Behavior ◽

Constitutive Models ◽

Strain Range ◽

Type Model ◽

Strain Rates ◽

Compression Tests ◽

Predictive Values ◽

Specific Strain ◽

Optimum Model

The flow behavior of the SnSbCu alloy is studied experimentally by the compression tests in the range of the strain rates from 0.0001 to 0.1 s−1 and temperature from 293 to 413 K. Based on the experimental data, three constitutive models including the Johnson–Cook (J–C), modified Zerilli–Armstrong (Z–A), and Arrhenius-type (A-type) models are compared to find out an optimum model to describe the flow behavior of the SnSbCu alloy. The results show that the J–C model could predict the flow behavior of the SnSbCu alloy accurately only at some specific strain rates and temperature near the reference values. The modified Z–A and A-type constitutive models can give better fitting results than the J–C model. While, at high strains, the predictive values of the modified Z–A model have larger errors than those at low strains, which means this model has limitations at high strains. By comparison, the A-type model could predict the experimental results accurately at the whole strain range, which indicates that it is a more suitable choice to describe the flow behavior of the SnSbCu alloy in the focused range of strain rates and temperatures. The work is beneficial to solve the tribological problem of the bearing of the marine engine by integrating the accurate constitutive model into the corresponding numerical model.

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Considerations for the design of polymeric biodegradable products

Journal of Polymer Engineering ◽

10.1515/polyeng-2012-0150 ◽

2013 ◽

Vol 33 (4) ◽

pp. 293-302 ◽

Cited By ~ 12

Author(s):

André C. Vieira ◽

Rui M. Guedes ◽

Volnei Tita

Keyword(s):

Experimental Data ◽

Constitutive Models ◽

Tensile Tests ◽

Failure Criteria ◽

Numerical Approach ◽

Life Cycles ◽

Strength Failure ◽

First Order Kinetics ◽

User Material Subroutine ◽

Degradation Time

Abstract Several biodegradable polymers are used in many products with short life cycles. The performance of a product is mostly conditioned by the materials selection and dimensioning. Strength, maximum strain and toughness will decrease along its degradation, and it should be enough for the predicted use. Biodegradable plastics can present short-term performances similar to conventional plastics. However, the mechanical behavior of biodegradable materials, along the degradation time, is still an unexplored subject. The maximum strength failure criteria, as a function of degradation time, have traditionally been modeled according to first order kinetics. In this work, hyperelastic constitutive models are discussed. An example of these is shown for a blend composed of poly(L-lactide) acid (PLLA) and polycaprolactone (PCL). A numerical approach using ABAQUS is presented, which can be extended to other 3D geometries. Thus, the material properties of the model proposed are automatically updated in correspondence to the degradation time, by means of a user material subroutine. The parameterization was achieved by fitting the theoretical curves with the experimental data of tensile tests made on a PLLA-PCL blend (90:10) for different degradation times. The results obtained by numerical simulations are compared to experimental data, showing a good correlation between both results.

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Study on the Choice of Constitutive and Fatigue Models in Solder Joint Life Prediction

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2002-39676 ◽

2002 ◽

Cited By ~ 6

Author(s):

Krishna Tunga ◽

James Pyland ◽

Raghuram V. Pucha ◽

Suresh K. Sitaraman

Keyword(s):

Experimental Data ◽

Fatigue Life ◽

Solder Joint ◽

Predictive Models ◽

Life Prediction ◽

Constitutive Models ◽

Ball Grid Array ◽

Time Dependent ◽

Dependent Behavior ◽

Ball Grid Array Packages

Various constitutive and fatigue-life predictive models for lead-tin solders in SBGA (Super Ball Grid Array) packages are studied and compared with the results from experimental data. Two solder compositions, 62Sn/36Pb/2Ag and 63Sn/37Pb are studied in this work. The fatigue life of 62Sn/36Pb/2Ag solder is studied using different constitutive models that take into consideration both the time-independent and time-dependent behavior of the solder. The fatigue life of 62Sn/36Pb/2Ag solder is predicted using an energy-based predictive model and compared with the experimental data. The choice of various predictive models on the solder joint life is studied using 63Sn/37Pb solder. Various predictive models, available in the literature, for eutectic and near eutectic solder compositions are studied to predict the fatigue life. Guidelines are provided for selecting constitutive and predictive models with appropriate damage metrics.

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Evolution of Anand Parameters With Elevated Temperature Aging for SAC Leadfree Alloys

ASME 2020 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems ◽

10.1115/ipack2020-2658 ◽

2020 ◽

Author(s):

Pradeep Lall ◽

Vikas Yadav ◽

Jeff Suhling ◽

David Locker

Keyword(s):

Experimental Data ◽

High Strain ◽

Constitutive Models ◽

Tensile Tests ◽

Model Parameters ◽

Strain Rates ◽

Automotive Electronics ◽

High Strain Rates ◽

Operating Temperatures ◽

Electronic Assemblies

Abstract Electronic equipment in automotive, agricultural and avionics applications may be subjected to temperatures in the range of −55 to 200°C during storage, operation and handling in addition to high strain-rates. Strain rates in owing to vibration and shock may range from 1–100 per sec. Temperature in electronic assemblies depends typically on location, energy dissipation and thermal architecture. Some investigators have indicated that the required operating temperature is between −40 to 200°C for automotive electronics located underhood, on engine, on transmission. Prior data indicates the evolution of mechanical properties under extended exposures to high temperatures. However, the constitutive models are often only available for pristine materials only. In this paper, effect of low operating temperatures (−65°C to 0°C) on Anand-model parameters at high strain rates (10–75 per sec) for aged SAC (SAC105 and SAC-Q) solder alloys has been studied. Stress-Strain curves have been obtained at low operating temperatures using tensile tests. The SAC leadfree solder samples were subjected to isothermal-aged up to 4-months at 50°C before testing. Anand Viscoplastic model has been used to describe the material constitutive behavior. Evolution of Anand Model parameters for SAC solder has been investigated. The computed parameters of the experimental data were used to simulate the tensile test and verified the accuracy of the model. A good correlation was found between experimental data and Anand predicted data.

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