Methods and devices are disclosed for tracking site-specific microstructure evolutions and local mechanical fields in metallic samples deformed along biaxial strain paths. The method is based on interrupted bulge tests carried out with a custom sample holder adapted for SEM-based analytical measurements. Embodiments include elliptical dies used to generate proportional and complex strain paths in material samples. One example holding device includes a base having a floor and walls that extend to form a chamber for a sample, the floor having apertures for receiving a pressure-supplying fluid, a cover having an opening and configured such that the cover and base can be coupled together to tightly clamp a sample in the chamber, and washers disposed between the base and the cover, each washer having openings extending therethrough change at least one of a shape and a size of the opening formed in the cover.

Disclosed is a three-parameter strength reduction method for slope stability evaluation. The present disclosure reflects the difference in the attenuation and contribution of the cohesion, internal friction angle and tensile strength in the process of slope instability by reducing the three parameters by different reduction factors. Based on the sudden change of the characteristic point displacement of the slope as a criterion of slope instability, the present disclosure derives the fitting relationship between the characteristic point displacement and the cohesion reduction factor. The present disclosure assumes that the comprehensive safety factor satisfies a linear relationship with the cohesion reduction factor, the internal friction angle reduction factor and the tensile strength reduction factor and derives the relationship between the comprehensive safety factor and the cohesion reduction factor. Finally, the present disclosure summarizes and proposes a three-parameter strength reduction method and provides the steps for analyzing the slope stability through this method.

The present disclosure discloses a reciprocating rock fracture friction-seepage characteristic test device and method. The test device includes an X-axis shear system, a Y-axis stress loading system, a Z-axis stress loading system, a servo oil source system, 5 a pore pressure loading system, and a host. The X-axis shear system includes an X-axis EDC controller, an upper shear box, a lower shear box, an X-axis left hydraulic cylinder, an X-axis right hydraulic cylinder, an X-axis left pressure head, an X-axis right pressure head, an X-axis left pressure sensor, an X-axis right pressure sensor, an X-axis displacement sensor, and an X-axis 10 displacement sensor. The pore pressure loading system includes an air cylinder, a pressure gauge, a pressure reducing valve, a fluid inlet pipeline, a fluid outlet pipeline, and a flowmeter.

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.

A test system includes subsystems for application to a test sample of a range of conditions that might be encountered in an actual application. Conditions may include the presence of particular fluid environments, temperatures, pressures, and mechanical loads including tensile and bending loads. The system is particularly suited for elongated samples such as tubular products used in oil and gas applications, though a range of samples may be tested.

A footprint generator capable of applying a constant force includes: a base plate in which a target surface may be on an upper surface of the base plate; a shoe mounting member that is apart from the upper surface of the base plate and capable of mounting a shoe; a driving unit that is apart from the upper surface of the base plate and capable of moving the shoe mounting member up and down; and a force measuring unit configured to measure an impact force when the shoe mounting member descends and contacts the shoe with the target surface to generate a footprint on the target surface.

An impact test fixture capable of applying preload on a composite laminate, which is composed of a base, a clamping mechanism and a loading mechanism, where the clamping mechanism is positioned on an upper surface of the base and fixedly connected to the base through a bolt, and the loading mechanism is installed at an end of the base. A composite laminate is placed in a rectangular groove of the base. A first wedge block and a second wedge block are positioned in a base sliding groove between a pressing block and a baffle plate, and inclined planes of the two wedge blocks are oppositely installed; the baffle plate is matched with the base through a first fixing bolt and a second fixing bolt, a loading bolt passes through a screw hole at a side end of the base and is matched with the first wedge block.

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.

A horizontal jet-mechanical combined rock breaking test device and method. The device includes a horizontal base. One end of the horizontal base is provided with a multi-mode cutter head. A jet-mechanical combined cutter is provided on the multi-mode cutter head. The other end of the horizontal base is provided with a surrounding rock stress simulation bin for loading a rock sample. The multi-mode cutter head is connected to a driving mechanism, and the multi-mode cutter head is configured to advance and rotate horizontally along the horizontal base under the action of the driving mechanism, so that the jet-mechanical combined cutter is capable of acting on the rock sample.

Provided is a material performance testing system under a fixed multi-field coupling effect in a hypergravity environment, including a hoisted sealed cabin, a bearing frame, a high-temperature furnace, a mechanical test device, and a buffer device. The bearing frame and the high-temperature furnace are fixedly mounted inside the hoisted sealed cabin. The bearing frame is covered on the high-temperature furnace. The buffer device is mounted at a bottom of the high-temperature furnace. Upper and lower ends of the mechanical test device are connected in a top of the bearing frame and the bottom of the high-temperature furnace. A sample is connected and mounted at an end of the mechanical test device.