Functional Materials, 2017, № 1

Properties of the volume phase in the layerwise growth. Case of forming of new layer under effect of previous

2017-01-01T00:00:00Z

Properties of the volume phase in the layerwise growth. Case of forming of new layer under effect of previous Brodskii, R.Ye. It was studied in the work the properties of volume inclusions of transparent phase in an opaque sample, that grown layerwise. It was studied a case in which the regions of transparent phase of a new layer appear only above the regions of transparent phase of the previous layer. Numerical characteristics of this process - the average number of "islands" of transparent phase in a new layer on one such "island" of previous layer. It was research the formation of regions of the transparent phase in separate layers and formation of through "windows of transparency" in the final sample. The law of changing of transparent phase area with the number of layer was received at different values of . Mechanisms, that determine the form of different parts of the law was pointed. For final sample the distribution density of "windows" on area was obtained, analytically for separate exactly solvable case and numerically in the general case. It is shown that the density has three different parts, the properties of these parts was studied at different . It was found the law of change of the total transparency of the sample with .

Experimental study on mechanical behavior of RPC circular columns confined by high-strength stirrups under axial compression

2017-01-01T00:00:00Z

Experimental study on mechanical behavior of RPC circular columns confined by high-strength stirrups under axial compression Ming-Yang Chen; Wen-Zhong Zheng; Xiao-Meng Hou The axial compression mechanical behavior of Reactive Power Concrete (RPC) circular columns which confined by the spiral hoop of yield strength 600MPa are tested, and the tie spacing and volume tie ratio were used to evaluate the RPC columns failure modes, load-displacement relationship and yield characteristics of high-strength stirrups. The results show that the peak stress of the 250mm diameter circular column with no reinforcement can be up to 144.4MPa but with brittle failure mode, and the large volume tie ratio can increase the peak stress to 180MPa and failure by ductility; also, the high-strength spiral stirrups do not yield at the peak axial load, and the effective confined stress should be calculated according to the measured stirrups strain , and the remaining strength can be ensured the good ductility of the RPC specimens before reaching the ultimate failure mode; the peak strength and strain of RPC are proportional to linearly increase with effective confinement stress, but the proportion coefficient is smaller than that of ordinary concrete. The decline section of RPC stress-strain curve becomes smooth with the increase of effective binding stress, and the ductility coefficient of displacement gradually satisfies the ductility design requirements. The measured RPC stress-strain curve agrees well with the confined concrete Mander model and can be used conservatively. According to the test results, the calculation formula and the construction measurements of the axial compression capacity of the RPC with the spiral stirrup confined are put forward, which is convenient for the popularization and application of the confined RPC columns in the practical engineering.

Fabrication and mechanical performance of 3D woven basalt fiber composite materials

2017-01-01T00:00:00Z

Fabrication and mechanical performance of 3D woven basalt fiber composite materials Lihua Lv; Xuefei Zhang; Fang Ye; Yongfang Qian; Yuping Zhao; Guibin Liu Three kinds differently structural 3D woven fabrics with the basalt fiber filaments tows as warp and weft yarn were fabricated on common loom by reasonable design. And, three kinds differently structural 3D woven basalt fiber composite materials were obtained with vinyl ester resin as matrix materials and 3D woven fabrics as reinforced materials, by VARTM molding process (vacuum assisted resin transfer molding process). Then, the tensile and bending properties of three kinds differently structural 3D woven basalt fiber composite materials were tested through the universal testing machine. Results were shown that the 3D woven basalt fiber composite materials had excellent mechanical properties, but the different structures of 3D woven fabrics as reinforced materials shown a big difference on mechanical properties. As follows, the modulus of elasticity for tensile and modulus of elasticity for bending of the 3D orthogonal structure basalt fiber composite materials were the greatest, and that of the 3D throughout angle interlocking structure basalt fiber composite materials was the smallest. Meanwhile, the tensile elongation at break of the 3D throughout angle interlocking structure basalt fiber composite materials were the largest and that of the 3D layered angle interlocking structure basalt fiber composite materials was the smallest.

Influence of residual solvent on relaxation behavior of polymer films based on glycidyl derivatives of 3, 5, 7, 3',4'-pentahydroxyflavone

2017-01-01T00:00:00Z

Influence of residual solvent on relaxation behavior of polymer films based on glycidyl derivatives of 3, 5, 7, 3',4'-pentahydroxyflavone Mishurov, D.; Roshal, O.; Brovko, O. Structural parameters and optical anisotropy relaxation dynamics of cross-linked polymers obtained from 7,4'-diglycidyl-, 7,3',4'-triglycidyl- and 3,7,3',4'-tetraglycidyl ethers of quercetin (3,5,7,3',4'-pentahydroxyflavone) are investigated. Values of effective cross-linked density and molecular weight between the cross-linked units, as well as dynamics of after-poling polymer relaxation were analyzed for polymer films containing residual solvent (acetone) and solvent-free annealed samples. It was found that solvent removal leads to growth of cross-linked density and to decrease of molecular weight between the cross-linked units. It was found that relaxation dynamics of polymers based on 3,7,3',4'-tetraglycidyl quercetin does not depend on the presence of residual solvent. Solvent containing polymers based on 7,4'-diglycidyl- and 7,3',4'-triglycidyl ethers of quercetin have substantially faster relaxation dynamic than corresponding annealed polymers. The mechanism of the residual solvent influence on the relaxation dynamics of polymer films has been proposed.