The main objective of the present work was to synthesis polyamide 6 through anionic polymerization of ε-caprolactam in an internal mixer. The reaction time and the rheological properties of samples during the polymerization were studied. The samples were characterized by Thermo Gravimetry Analysis (TGA), Differential Scanning Calorimeter (DSC) and FT-IR spectrometer. The melt flow behavior and ...

The goal of this study was to determine the duration of time that ligaments from a study group need to be loaded in order to adequately determine their collective viscoelastic behavior. Rat ligaments were subjected either to creep or stress relaxation for 1,000 s or stress relaxation for 10,000 s to compare estimates of viscoelastic behavior for different test durations. Stresses versus time (r...

The macroscopic viscoelastic behavior of collagen gel was studied through relaxation time distribution spectrum obtained from stress relaxation tests and viscoelastic constitutive modeling. Biaxial stress relaxation tests were performed to characterize the viscoelastic behavior of collagen gel crosslinked with Genipin solution. Relaxation time distribution spectrum was obtained from the stress ...

Soft tissue characterization and modeling based on living tissues has been investigated in order to provide a more realistic behavior in a virtual reality based surgical simulation. In this paper, we characterize the nonlinear viscoelastic properties of intra-abdominal organs using the data from in vivo animal experiments and inverse FE parameter estimation algorithm. In the assumptions of quas...

This paper presents an experimental and numerical study of the folding, stowage, and deployment behavior of viscoelastic tape springs. Experiments show that during folding the relationship between load and displacement is nonlinear and varies with rate and temperature. In particular, the limit and propagation loads increase with the folding rate but decrease with temperature. During stowage, re...

needle insertion is a minimally invasive technique in diagnosing and treating tumors. however, to perform a surgery accurately, the tissue should have minimum amount of displacement during needle insertion so that it reaches the target tissue. therefore, the tissue membrane has to move less to decrease rupturing under the membrane. in this study, the effect of different design parameters on dis...

Much has been learned about the viscoelastic properties of the true vocal fold, including its linear and nonlinear viscoelastic properties under both tensile and shear deformation. Very little is known about the viscoelastic behavior of the false vocal fold, however. Clinical observations and computational modeling studies of phonation have suggested that the false fold could contribute to the ...