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A constitutive model for the time-dependent, nonlinear stress response of fibrin networks.

van Kempen TH, Peters GW, van de Vosse FN - Biomech Model Mechanobiol (2015)

Bottom Line: The results show three dominating nonlinear features: softening over multiple deformation cycles, strain stiffening and increasing viscous dissipation during a deformation cycle.A sensitivity analysis provides insights into the influence of the eight fit parameters.The model developed is able to describe the rich, time-dependent, nonlinear behavior of the fibrin network.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600MB, Eindhoven, The Netherlands, t.h.s.v.kempen@tue.nl.

ABSTRACT
Blood clot formation is important to prevent blood loss in case of a vascular injury but disastrous when it occludes the vessel. As the mechanical properties of the clot are reported to be related to many diseases, it is important to have a good understanding of their characteristics. In this study, a constitutive model is presented that describes the nonlinear viscoelastic properties of the fibrin network, the main structural component of blood clots. The model is developed using results of experiments in which the fibrin network is subjected to a large amplitude oscillatory shear (LAOS) deformation. The results show three dominating nonlinear features: softening over multiple deformation cycles, strain stiffening and increasing viscous dissipation during a deformation cycle. These features are incorporated in a constitutive model based on the Kelvin-Voigt model. A network state parameter is introduced that takes into account the influence of the deformation history of the network. Furthermore, in the period following the LAOS deformation, the stiffness of the networks increases which is also incorporated in the model. The influence of cross-links created by factor XIII is investigated by comparing fibrin networks that have polymerized for 1 and 2 h. A sensitivity analysis provides insights into the influence of the eight fit parameters. The model developed is able to describe the rich, time-dependent, nonlinear behavior of the fibrin network. The model is relatively simple which makes it suitable for computational simulations of blood clot formation and is general enough to be used for other materials showing similar behavior.

No MeSH data available.


Related in: MedlinePlus

Parameter values obtained by fitting the model to experimental results for networks that have polymerized for 2 (purple) or 1 (yellow) h. Results of three independent measurements are shown per condition (1,2,3), together with the mean value (m). The errorbar indicates the standard deviation. The parameter values illustrate that the networks that polymerized 1 h show more strain stiffening (, ), faster recovery after the LAOS sequence () and more viscous dissipation (, ) than the networks that polymerized 2 h
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Fig11: Parameter values obtained by fitting the model to experimental results for networks that have polymerized for 2 (purple) or 1 (yellow) h. Results of three independent measurements are shown per condition (1,2,3), together with the mean value (m). The errorbar indicates the standard deviation. The parameter values illustrate that the networks that polymerized 1 h show more strain stiffening (, ), faster recovery after the LAOS sequence () and more viscous dissipation (, ) than the networks that polymerized 2 h

Mentions: The observations that the networks that have polymerized for 1 h show more strain stiffening and recover faster also follows from the parameter values found by the model. Figure 11 shows the values for the eight parameters of the model for the networks that polymerized for 2 h (purple) and 1 h (yellow), for three samples of each condition and the mean value with standard deviation. The parameters that describe the strain stiffening are and . Although there is considerable variation between samples it is clear that the values of are higher for the networks that polymerized for 1 h. An exception to this is sample , which has a relatively low value of , but this is balanced by a high value for , which also implies more strain stiffening.


A constitutive model for the time-dependent, nonlinear stress response of fibrin networks.

van Kempen TH, Peters GW, van de Vosse FN - Biomech Model Mechanobiol (2015)

Parameter values obtained by fitting the model to experimental results for networks that have polymerized for 2 (purple) or 1 (yellow) h. Results of three independent measurements are shown per condition (1,2,3), together with the mean value (m). The errorbar indicates the standard deviation. The parameter values illustrate that the networks that polymerized 1 h show more strain stiffening (, ), faster recovery after the LAOS sequence () and more viscous dissipation (, ) than the networks that polymerized 2 h
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4563000&req=5

Fig11: Parameter values obtained by fitting the model to experimental results for networks that have polymerized for 2 (purple) or 1 (yellow) h. Results of three independent measurements are shown per condition (1,2,3), together with the mean value (m). The errorbar indicates the standard deviation. The parameter values illustrate that the networks that polymerized 1 h show more strain stiffening (, ), faster recovery after the LAOS sequence () and more viscous dissipation (, ) than the networks that polymerized 2 h
Mentions: The observations that the networks that have polymerized for 1 h show more strain stiffening and recover faster also follows from the parameter values found by the model. Figure 11 shows the values for the eight parameters of the model for the networks that polymerized for 2 h (purple) and 1 h (yellow), for three samples of each condition and the mean value with standard deviation. The parameters that describe the strain stiffening are and . Although there is considerable variation between samples it is clear that the values of are higher for the networks that polymerized for 1 h. An exception to this is sample , which has a relatively low value of , but this is balanced by a high value for , which also implies more strain stiffening.

Bottom Line: The results show three dominating nonlinear features: softening over multiple deformation cycles, strain stiffening and increasing viscous dissipation during a deformation cycle.A sensitivity analysis provides insights into the influence of the eight fit parameters.The model developed is able to describe the rich, time-dependent, nonlinear behavior of the fibrin network.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600MB, Eindhoven, The Netherlands, t.h.s.v.kempen@tue.nl.

ABSTRACT
Blood clot formation is important to prevent blood loss in case of a vascular injury but disastrous when it occludes the vessel. As the mechanical properties of the clot are reported to be related to many diseases, it is important to have a good understanding of their characteristics. In this study, a constitutive model is presented that describes the nonlinear viscoelastic properties of the fibrin network, the main structural component of blood clots. The model is developed using results of experiments in which the fibrin network is subjected to a large amplitude oscillatory shear (LAOS) deformation. The results show three dominating nonlinear features: softening over multiple deformation cycles, strain stiffening and increasing viscous dissipation during a deformation cycle. These features are incorporated in a constitutive model based on the Kelvin-Voigt model. A network state parameter is introduced that takes into account the influence of the deformation history of the network. Furthermore, in the period following the LAOS deformation, the stiffness of the networks increases which is also incorporated in the model. The influence of cross-links created by factor XIII is investigated by comparing fibrin networks that have polymerized for 1 and 2 h. A sensitivity analysis provides insights into the influence of the eight fit parameters. The model developed is able to describe the rich, time-dependent, nonlinear behavior of the fibrin network. The model is relatively simple which makes it suitable for computational simulations of blood clot formation and is general enough to be used for other materials showing similar behavior.

No MeSH data available.


Related in: MedlinePlus