Stress relaxation and structural analysis were used to investigate the zonally differentiated microstructural response to compression of the integrated cartilage-on-bone tissue system. Fifteen cartilage-on-bone samples were divided into three equal groups and their stress relaxation responses obtained at three different levels of axial compressive strain defined as low (~20%), medium (~40%) and...

Tissue engineering of various musculoskeletal or cardiovascular tissues requires scaffolds with controllable mechanical anisotropy. However, native tissues also exhibit significant inhomogeneity in their mechanical properties, and the principal axes of anisotropy may vary with site or depth from the tissue surface. Thus, techniques to produce multilayered biomaterial scaffolds with controllable...

Recently, we reported on the axial-shear strain fill-in of the interior of loosely bonded stiff elliptical inclusions in a soft background at non-normal orientations, and the lack of fill-in in firmly bonded inclusions at any orientation. In this paper, we report on the experimental validation of the simulation studies using tissue-mimicking gelatin-based phantoms. We also show a few confirmato...

thin films of polymer doped with nonlinear optical organic dye, disperse red 1, at thickness of 1 to 2 micrometers, were prepared and studied. in order to induce an axial and orientational alignment of dye molecules within polymer matrix, a contact electric field poling was used. by this process the inherent inversion symmetry in the polymer matrix was eliminated to achieve the desired macrosco...

Ultrasonic strain imaging has been applied to echocardiography and carries great potential to be used as a tool in the clinical setting. Two-dimensional (2D) strain estimation may be useful when studying the heart due to the complex, 3D deformation of the cardiac tissue. Increasing the framerate used for motion estimation, i.e. motion estimation rate (MER), has been shown to improve the precisi...

A major disadvantage of the current practice of elastography is that only the axial component of the strain is estimated. The lateral and elevational components are basically disregarded, yet they corrupt the axial strain estimation by inducing decorrelation noise. In this paper, we describe a new weighted interpolation method operating between neighboring RF A-lines for high precision tracking...

In this study, experimental study on six RC columns with different slenderness ratios under axial rapid loading was conducted to investigate the axial compression behaviour of RC columns considering the effect of strain rates. The failure pattern of the specimens and the relations of axial loading versus the axial deformation were described. From the test results, the specimens under static and...

This paper proposes a novel fully nonlinear refined beam element for pre-twisted structures undergoing large deformation and finite untwisting. The present model is constructed in the twisted basis to account effects of geometrical nonlinearity initial twist. Cross-sectional allowed by introducing Lagrange polynomials framework Carrera unified formulation. principle virtual work applied obtain ...

The dynamic behavior of porcine brain tissue, obtained from a series of in vitro observations and experiments, is analyzed and described here with the aid of a large strain, nonlinear, viscoelastic constitutive model. Mixed gray and white matter samples excised from the superior cortex were tested in unconfined uniaxial compression within 15h post mortem. The test sequence consisted of three su...

This paper investigates bifurcation and chaos in transverse motion of axially accelerating viscoelastic beams. The Kelvin model is used to describe the viscoelastic property of the beam material, and the Lagrangian strain is used to account for geometric nonlinearity due to small but finite stretching of the beam. The transverse motion is governed by a nonlinear partial-differential equation. T...