Mechanical properties of sandstone under hydro-mechanical coupling

Abstract

Study of mechanical properties of rock under hydro-mechanical coupling. The MTS815 rock mechanics system is used to perform triaxial compression tests of water-saturated sandstones under different confining pressures and pore water pressures. The results show that the peak deviation stress and its corresponding axial strain, residual deviation stress, initial deviation stress of dilation and deformation modulus of water-saturated sandstone are related to pore water pressure and confining pressure. They decrease with the increase of pore water pressure and increase with the increase of confining pressure. Poisson’s ratio and angle of rupture of water-saturated sandstone increase with pore water pressure. Based on the effective stress principle and Mohr–Coulomb criterion, the effective cohesion and effective residual cohesion of sandstone are 11.49 and 3.13 MPa, respectively, and the effective angle of internal friction and effective residual angle of internal friction are 38.32° and 25.32°, respectively. In addition, according to the variation relationship of sandstone strength, the relative strength criterion of sandstone under hydro-mechanical coupling is established.

Processability‐enhanced aromatic thermotropic liquid crystalline copolyesters via the introduction of the unsymmetrical units

“…With the excellent mechanical properties, thermal stability and chemical resistance, ect., thermotropic liquid crystalline polyesters (TLCP) have been widely explored as the functional polymers 1 and processing additives to improve processing properties. 2,3 The TLCP-based materials have been widely used in the aerospace, communication equipment, automotive parts industries, and so forth, for the fire protection, 4 personal protection and other extreme temperature environments. 5,6 Nevertheless, the currently reported TLCP materials displays the relatively low glass transition temperature and high melting temperature.…”