A bond test apparatus includes a test tool, a stage for mounting a bond for testing, and a drive mechanism comprising a voice coil. The voice coil is coupled to either the stage or to the test tool and is configured to provide relative movement between the stage and the test tool such that the bond applies a test force to the test tool. The bond test apparatus can also include a velocity sensor configured to sense an instantaneous relative velocity between the stage and the test tool, and a controller configured to control the drive mechanism in response to a signal from the velocity sensor. The bond test apparatus can also include a retarding mechanism coupled to the stage or the test tool and configured to apply, in response to relative movement between the stage and the test tool, a retarding force opposing the driving force.

A method for characterizing complexity of rock fracture based on fractal dimension and a device thereof are provided. The method includes steps of: collecting rock fracture samples of a rock, and collecting basic parameters of the rock; determining a fractal dimension of a rock fracture morphology of the rock; calculating the fractal dimension of the rock; calculating a complexity coefficient Fc of rock fracture of the rock; and characterizing a complexity of rock fracture of the rock based on the complexity coefficient Fc of rock fracture of the rock. In the present invention, combined with the fractal geometry theory, fracture complexity coefficient of shale rocks is redefined and calculated to accurately characterize rock fracture morphology, so that characteristics of rock fracture morphology is correctly understood and affecting factors of fracture morphology is analyzed.

The invention relates to a method for preparing a tensile test on an elongate, more particularly fibrous, specimen, for example on a collagen fibril, comprising the steps of: -providing the elongate specimen; - attaching a handling particle to the elongate specimen; - providing a force sensor, on which a retainer for the handling particle on the elongate specimen is disposed; - connecting a handling apparatus to the handling particle on the elongate specimen; and - connecting the handling particle on the elongate specimen to the retainer on the force sensor by means of the handling apparatus. The invention also relates to a method and a device for performing a tensile test on an elongate specimen.

A testing apparatus includes a support unit that supports a lower surface side of a test piece, a pressing unit having an indenter that presses the test piece supported by the support unit, a drive unit that raises and lowers the pressing unit, a load measurement instrument that measures a load generated when the indenter presses the test piece supported by the support unit, and a controller that controls raising and lowering of the pressing unit. The controller is configured to be capable of stopping movement of the indenter when a measurement value of the load measurement instrument has turned from a rise to a fall after the indenter has started pressing of the test piece.

Provided is a test system for hard rock breaking by a microwave intelligent loading based on true triaxial stress, including: a true triaxial stress loading device consisting of a loading frame and a rock sample moving structure; a microwave-induced hard rock breaking device consisting of an excitation cavity, a rectangular waveguide, a magnetron, a thermocouple, a circulator, a cold water circulation device, a flowmeter, a power meter, an automatic impedance tuner, a coupler, a microwave heater and a shielding cavity; and a dynamic rock response monitoring and intelligent microwave parameter control system consisting of a CCD industrial camera, a temperature acquisition device and an anti-electromagnetic high-temperature resistant acoustic wave-acoustic emission integrated sensor. According to the test system, the microwave-induced hard rock breaking test, dynamic monitoring temperature and rock breaking in microwave-induced breaking process and intelligent control over microwave power and heating time are achieved.

A fracture toughness testing machine of the invention makes it possible to evaluate fracture toughness of a specimen in pure mode such that the effect of thermal residual stresses is removed, when the stresses are present in the specimen obtained by bonding dissimilar materials. The testing machine includes: testing-load applying means for applying a predetermined testing load to the specimen, in which the stresses are present; and cancelling-load applying means for applying a cancelling load to the specimen to cancel the stresses therein. The cancelling-load applying means includes: a pressing-force applying portion that applies a pressing force to the specimen as the canceling load; and a pressing-force determining portion that determines magnitude of the force. The pressing-force determining portion calculates the magnitude of the force using pre-stored equations so that an energy release rate related to in-plane shear mode crack deformation becomes zero.

Disclosed is a method for determining a whole macro-micro process of rock deformation and failure based on a four-parameter test, including following steps: firstly, obtaining acoustic emission data and deformation data of a sample in a compression test, and then calculating the deformation data according to a finite deformation theory to obtain a mean rotation angle θ at each stress level; using Grassberger-Procaccia (G-P) algorithm to calculate the acoustic emission data, and obtaining a fractal dimension of a temporal distribution D.sub.T of an acoustic emission signal and calculating a fractal dimension of a spatial distribution D.sub.S; obtaining a microscopic morphology of a fracture surface by scanning electron microscope (SEM) test after the compression test, and calculating a fractal dimension D.sub.A of the fracture surface; finally, obtaining a mathematical trend relationship between θ and D.sub.T, D.sub.S and D.sub.A according to a comprehensive analysis of D.sub.T, D.sub.S, D.sub.A and θ.

A method includes determining a perforation tunnel geometry of a perforation tunnel in a solid sample, the perforation tunnel created by activating a shaped charge in proximity to the solid sample. The method also includes performing a first flow test on the solid sample and creating an analog aperture having an aperture geometry in a solid sample analog of the solid sample, wherein the aperture geometry and the perforation tunnel geometry satisfies a similarity threshold. The method also includes performing a second flow test on the solid sample analog and determining a shaped charge effect based on a comparison between a second flow test result and a first flow test result.

Methods, systems, and computer-readable medium to perform operations for identifying fracture barriers in a well. The operations include converting rebound hardness values of a rock specimen from the well to unconfined compressive strength (UCS) values, where each of the rebound hardness values corresponds to a respective coordinate of a measurement grid imposed on the specimen. The operations further include, for each column of the grid, plotting the UCS values versus depth. Further, the operations include mapping, based on a maximum UCS value and a minimum UCS value, a relative strength contour plot for the specimen. Yet further, the operations include mapping, based on a fixed strength range, an absolute strength contour plot for the specimen. In addition, the operations include determining, based on the relative strength contour, the absolute strength contour, and mineralogy of the rock specimen, that the rock specimen is indicative of a fracture barrier in the well.

Disclosed is a real-time nondestructive observation and two-phase seepage test system for a fracture of an in-situ fractured gas-bearing reservoir, which comprises a stress loading system, a high-voltage electric pulse fracturing operation system, a water-gas two-phase seepage system and an in-situ CT scanning system; the stress loading system comprises a pressure chamber, an axial pressure loading module and a confining pressure loading module; the high-voltage electric pulse fracturing operation system comprises a high-voltage electric pulse generation module, a high-voltage electric pulse signal monitoring module and a protection module; the water-gas two-phase seepage system comprises a water-gas pressure loading module and a flow data acquisition module; and the in-situ CT scanning system comprises a radiation source, a flat panel detector and a CT scanning detection mechanism.