Experiments show that the drilling deformation of rock is partly in the deformation stage of steady-state creep when the temperature is below 500 ℃ and the hydrostatic stress is below 150 MPa. In this paper, the generalized Kelvin model is selected to reflect its characteristics. By using the Laplace transform and the inverse Laplace transform, the analytical solution of the drilling's radial displacement is obtained, and the relationship between the model parameters, the temperature and the stress are obtained by taking the temperature-stress coupling effect into consideration. After applying the relation to a fitting calculation, it is shown that the model is rational and reliable and can represent the creep deformation characteristics of the granite in steady state and be used to obtain the creep parameters of the granite under high temperature and high pressure. The results can be used in the drilling construction and maintenance, the drilling deformation prediction, and the drilling shaft lining stability analysis during the development of hot dry rock geothermal energy resources.
Based on the linear elastic plate theory, the rigidity of a concave template of a right angle trapezoid cross section made of homogeneous, continuous and isotropic material with a circular hole is calculated. At first, a mechanical and mathematical calculation model is built. Secondly, the third order variable coefficient differential equation expressed in deflection is obtained with boundary conditions. And then, the deflection is obtained, as well as the rigidity. Finally, an application example is given.
The mechanics of cochlea is the core of hearing sciences and physiological acoustics, as well as a representative biomechanics topic. The study of cochlear mechanical properties could promote the related studies of psychoacoustics. This paper reviews the mechanics of the cochlea in two parts, the macro and micro mechanics, focusing on the development trend of the cochlear mechanics and application prospects. It is suggested that the cochlea is a part of the inner ear and its mechanical response provides us with many aspects of our amazing sensitive and selective hearing, with an accurate frequency response from 20~20 000 Hz and with the stimulus signal being able to be amplified more than 4 000 times.