It is proved that elliptically-polarized finite-amplitude inhomogeneous plane waves may not propagate in an isotropic elastic material subject to the constraint of incompressibility. The waves considered are harmonic in time and exponentially attenuated in a direction distinct from the direction of propagation. The result holds whether the material is stress-free or homogeneously deformed.
Third- and fourth-order constants of incompressible soft solids and the acousto-elastic effect
声弹性研究的是小振幅波在变形固体中的传播。先前建立的增量弹性动力学的精确非线性弹性的结果是有用的第三和第四阶弹性常数的测定，特别是在不可压缩的各向同性软固体的情况下，其中的表达式是特别简单的。具体地说，这只是扩展$ρv^2$的表达式的问题，其中$ρ$是质量密度，v是波速，根据经受单轴拉伸的块的伸长$e$。分析表明，在所得到的表达式：$ρv^2 = a + be + ce^2$，说，$a$线性依赖于$μ$ ; $b$对$μ$和$A$ ;和$c$对$μ$，$A$，和$D$，各自的不可压缩弹性的第二，第三和第四阶常数，体剪切波和表面波。
We find the strain energy function for isotropic incompressible solids exhibiting a linear relationship between shear stress and amount of shear, and between torque and amount of twist, when subject to large simple shear or torsion deformations. It is inclusive of the well-known neo-Hookean and the Mooney-Rivlin models, but also can accommodate other terms, as certain arbitrary functions of the principal strain invariants. Effectively, the extra terms can be used to account for several non-linear effects observed experimentally but not captured by the neo-Hookean and Mooney-Rivlin models, such…
Using shear wave elastography, we measure the changes in the wave speed with the stress produced by a striated muscle during isometric voluntary contraction. To isolate the behaviour of an individual muscle from complementary or antagonistic actions of adjacent muscles, we select the flexor digiti minimi muscle, whose sole function is to extend the little finger. To link the wave speed to the stiffness, we develop an acousto-elastic theory for shear waves in homogeneous, transversely isotropic, incompressible solids subject to uniaxial stress. We then provide measurements of the apparent shear…
