Mechanical behaviors of tension and relaxation of tongue and soft palate: Experimental and analytical modeling.

Highlights • Uniaxial tension test and stress relaxation test on 39 fresh tissue samples from four five-month-old boars (65 ± 15 kg) are conducted. • The stress-strain mechanical characteristics of the tongue and soft palate samples are demonstrated to be non-linear and can be divided into two stages: the IRS stage and the LRS stage. • Significant stress relaxation generates is obtained for all the tongue and soft palate samples and almost half of the stress attenuation is completed in the first 3 s. • A constitutive model is proposed to represent the mechanical behaviors of the muscle tissues and the fitting results are very good. Abstract This study is to characterize mechanical properties of uniaxial tension and stress relaxation responses of muscle tissues of tongue and soft palate. Uniaxial tension test and stress relaxation test on 39 fresh tissue samples from four five-month-old boars (65 ± 15 kg) are conducted. Firstly, the rationality of the samples' dimension design and experimenal data measurement is validated by one-way ANOVA F-type test. Mechanical properties, including stress-strain relationship and stress relaxation characteristic, are then investigated in details to show the nonlinear behaviors of the tissue samples clearly. Finally, a constitutive model of representing the mechanical properties is formulated within the nonlinear integral representation framework proposed by Pinkin and Rogers, and corresponding material parameters are fitted to the experimental data based on the Levenberg-Marquardt minimization algorithm. The results of the fitting comparison prove that the formulated constitutive model can capture the observed nonlinear behaviors of the muscle tissue samples in both the axial tension and stress relaxation experiments. [ABSTRACT FROM AUTHOR]