Characterization Of Shear Behavior Research Articles

Characterization of shear behavior and damage mechanism of periodic thermal loading sandstone based on NMR technique

We conducted research on the influence of periodic thermal loading on the shear behavior of sandstone through a series of direct shear tests with the aid of acoustic emission techniques. By capturing the evolution in pore structure with nuclear magnetic resonance technology and fractal theory to analyze the damage mechanism. The shear testing reveals that the periodic heating and air cooling sample exhibits a lower shear resistance compared to the continuous heating rock, with more pronounced differences observed in the water cooling samples. The peak shear strength and stiffness are greatly influenced by temperature and thermal loading methods, while the ultimate shear strength remains largely unaffected. Compared to samples with less severe damage, the acoustic emission macrocracking proportion of sandstone with more damage after thermal loading is more significant, corresponding to a smaller b-value. The study of the evolution in pore structure shows that mesopores and macropores exhibit favorable fractal characteristics distinct from micropores. The fractal dimension of mesopores and macropores are observed to be influenced by heating temperature and periodic thermal loading, as evidenced by their negative correlation with the thermal damage variable. After thermal loading, there was a negative correlation between porosity and fractal dimension in mesopores and macropores, indicating that the more severe the damage to the pore structure, the smaller the fractal dimension. The shear strength of periodic thermal loaded sandstone is closely related to the evolution of fractal dimension. The presence of thermal enhancement at 400 °C has been confirmed for the first time through fractal dimension analysis.

Characterization of Shear Behavior in Stainless Steel Wire Mesh Using Bias-Extension and Picture Frame Tests

AbstractThe main purpose of this paper is to find a suitable method for determining the in-plane shear characteristics of a type of “cellular metal” plain-woven stainless steel wire mesh. That no r...

Characterization of shear behaviour in consolidated granular biomass

A new vane shear tester is proposed for the determination of the shear strength in consolidated samples of granular biomass. Measurements are performed using forest woodchips with a normal pressure in the range 5–30kPa applied at rotation rates of 3–13rpm. The maximum torque is found to be affected by the normal pressure and time of compression. The rotation speed is not found to have a significant influence on the shear strength. The new apparatus is an efficient tool for determining the mechanical characteristics of granular biomass. The results are in general agreement with those given by the standard Jenike method, but the new technique makes testing easier and faster. Quantitative differences between the results obtained using the two methods are possibly a result of the different modes of load application and the geometry of the shear surface.

Simulation Analysis on Shear Behavior of RC Beams with Near-Surface Mounted GFRP Bars

This paper focuses on the characterization of shear behavior of RC beams strengthened with Near-Surface Mounted (NSM) GFRP bars. Based on ABAQUS, the finite element model for the shear behavior is established and the simulated results are compared with the test results. The parameters including spacing and inclination of GFRP bars, mechanical properties of the groove-filling epoxy, stirrup ratio and shear-span ratio of the specimen beams for the shear behavior are discussed. The simulated results show that there has a good agreement with the experiment results. The beams strengthened with NSM GFRP bars have a significant improvement in shear capacity. Further more, the analysis results on the parameters indicate that ultimate shear capacity of the beam strengthened with NSM-GFRP bars gradually increases with the decrease of spacing of GFRP bars. The ultimate bearing capacity increases of the strengthened beam with inclination of 45° is the more larger than those of 60° and 90°. The different types of epoxy adhesive and shear-span ratio have a great influence on the load-deflection curves of the strengthened beams.