A method for measuring micro-scale strength and residual strength of brittle rocks, including: performing micro-CT scanning on a target area; obtaining loading and unloading curves and an elastic modulus of the rock via micro indentation experiment; performing dimensionless analysis based on Buckinham's -theorem to obtain relation between the loading and unloading curves and elastic modulus, indentation depth, initial and residual strengths; reconstructing a grid model of micro rock matrix at the target area and indenter; performing micro indentation numerical simulation based on Mohr-Coulomb criterion to obtain loading and unloading curves under different strengths and residual strengths; fitting a formula between simulated work of the indenter and initial and residual strengths at h/R of 0.1 and 0.15; and substituting experimental values of the work into the formula to plotting curves of initial and residual strengths under two indentation depths, where coordinates of an intersection point represent micro-scale initial and residual strengths.

A racquet extends along a longitudinal axis and is capable of being tested under a racquet lateral bending test and a racquet torsional stability test. The racquet lateral bending test includes mounting the racquet in a first orientation to a first test fixture at a first longitudinal location, attaching a clamp to the racquet at a second location, operably engaging a deflection indicator to the clamp, applying a first predetermined weight to the racquet at a third location, and removing the first weight to obtain a lateral deflection measurement of the racquet with respect to the longitudinal axis. The racquet torsional stability test includes mounting the racquet to second and third test fixtures at sixth and seventh locations of the racquet, respectively, placing a third predetermined weight on an arm extending from the second test fixture, removing the third predetermined weight to obtain an angular deflection about the axis. The racquet comprises a frame including head and handle portions and a throat portion positioned between the head and handle portions. The head portion forms a hoop that defines a string bed plane. When the racquet is tested under the racquet lateral bending test, the racquet has a lateral deflection of at least 6.0 mm when measured in a direction that is parallel to the plane and perpendicular to the axis. When the racquet is tested under the racquet torsional stability test, the racquet has an angular deflection of less than 5.0 degrees about the axis.

Apparatus and methods of evaluating brittleness by measuring force applied to an electrode specimen by simulating a wound state of a jelly-roll type electrode assembly are disclosed herein. In an embodiment, a brittleness evaluation apparatus includes a jig unit, a driving unit, and a measurement analyzing unit. The jig unit includes two jigs, a groove formed between the jigs, a pressing plate, and guides. The jigs facing each other and have top surfaces formed in a horizontal plane and configured to receive a specimen arranged on the top surfaces along a length direction extending between and along the top surfaces. The pressing plate is arranged perpendicular to the length direction and configured to cause the specimen to bend by descending into the groove. The guides are located on each of the top surfaces of the jigs and configured to prevent distortion of the specimen during descent of the pressing plate.

The invention pertains to performing bonding strength testing between a test material and a container. A sample preparation device to make a test sample was disclosed. This device included a container with an insert on each end. The inserts have a portion that protrudes into the container. When test material is added to the sample preparation device, a groove was formed in test sample. These grooves reduce the amount of boundary effects that are present during testing. A system and method for performing bond strength testing was also disclosed. In this system, a test sample was formed using the sample preparation device. This is placed upon a support and a half-spherical force applier is placed on top of the test sample. A press is used to apply force to the force applier and indirectly to the test sample.

Method for characterizing a material (10), characterized in that it comprises the steps of carrying out a bending test and calculating a cross-section moment, M of said material (10) using the following equation: $M=\frac{F.Math.L_m\left({}_1\right)}{2.Math.{\cos }^2\left({}_1\right)}$
where F is the applied bending force, L.sub.m (.sub.1) is the moment arm, and .sub.1 is the bending angle. The expression for the moment, M, fulfils the condition for energy equilibrium:
Fds=2Md.sub.2
when the true bending angle, .sub.2 is: ${}_1-\frac{t.Math.\sin \left({}_1\right)}{L_m}d{}_1.$

A bending test device to bend a product as a test includes a base, a driving mechanism, and a bending mechanism. The driving mechanism and the bending mechanism are set on the base. The bending mechanism includes a supporting member, a rotating plate, a first holding part, and a second holding part. The supporting member is set on the base. The rotating plate is rotatably set on the supporting member. The rotating plate connects to the driving mechanism. The first holding part and the second holding part are set on the rotating plate. The first holding part clamps a first part of a workpiece, the second holding part clamps a second part of the workpiece. The driving mechanism rotates the rotating plate and thus drives the second holding part to rotate and bend the workpiece.

A system for simulating in situ drilling and treatment conditions on a core sample from a subterranean formation. The system re-creates various subterranean loads and temperatures on a test sample representative of actual in situ conditions from the particular formation while a test structure within the system performs drilling activities on the core sample using drilling and treating under evaluation for use in the particular subterranean formation. Thus, the impact on selected drilling and treating fluids can be evaluated as well as the impact those fluids had on a sample from the subterranean formation under in situ conditions.

The invention discloses a method for evaluating the longitudinal deformation of proppant pack, mainly comprising the following steps: displace the proppant evenly on one steel sheet and cover the proppant with another same steel sheet; place pistons on the outer surface of two steel sheets respectively to form a test unit; place the test unit on fracture conductivity tester, compact the proppant pack at a pressure of 0.6 MPa, measure the width between the two steel sheets at the four corners of the steel sheet, and calculate the average results; install the left and right displacement meters, increase the closure pressure from 6.9 MPa to 69 MPa with an increment of 6.9 MPa/time by pressure control system, record the readings of the left and right displacement meters after the pressure is increased each time and the meter reading is stable, and work out the total deformation of the experimental equipment and the proppant; make a curve chart of the relationship between pack thickness and pressure, and characterize the proppant pack deformation with Young's modulus. The evaluation method disclosed in the present invention makes up the technical gap in the study of proppant pack deformation in the prior art.

A system for in-situ testing of mechanical properties of materials in static and dynamic load spectra, that includes: an Arcan biaxial clamping subsystem, a press-in test subsystem, a biaxial fatigue test subsystem, a biaxial pre-tension loading subsystem, a signal detection subsystem, and a support and adjustment subsystem. A combined guide mechanism in the Arcan biaxial clamping subsystem is rigidly connected to a guide mechanism support block, an x-direction three sensor base and a y-direction force sensor base in the support and adjustment subsystem by threaded connections, respectively. A laser transmitter, a voice coil motor and a laser receiver in the press-in test subsystem are rigidly connected to a two-degree-of-freedom electric moving platform for the laser transmitter, a two-degree-of-freedom electric moving platform for the voice coil motor and a two-degree-of-freedom electric moving platform for the laser receiver in the support and adjustment subsystem by threaded connections, respectively.

The present invention provides a self-healing method for fractured SiC amorphous nanowires. A goat hair in a Chinese brush pen of goat hair moves and transfers single crystal nanowires under an optical microscope. On an in-situ nanomechanical test system of a TEM, local single crystal nanowires are irradiated with an electron beam for conducting amorphization transformation. Amorphous length of a single crystal after transformation is 60-100 nm. A fracture strength test is conducted on the amorphous nanowires in the single crystal after transformation in the TEM; and fracture strength of the amorphous nanowires is 9-11 GPa. After the amorphous nanowires are fractured, unloading causes a slight contact between the fractured end surfaces; and self-healing of the nanowires is conducted after waiting for 16-25 min in a vacuum chamber of the TEM. Atom diffusion is found at a healed fracture through in-situ TEM representation; and recrystallization is found in the amorphous nanowires. The present invention provides a method for realizing self-healing for fractured SiC amorphous nanowires without external intervention.