An apparatus for performing a contact mechanics test in a substrate includes a stylus having at least two contact elements. Each contact element has a contact profile, and the contact elements are disposed in the stylus to define a stretch passage therebetween. The stylus is configured to deform the substrate so as to cause the substrate to flow between the contact elements and induce tension in the substrate in order to generate and preserve micromodifications in the substrate. Methods of performing a contact mechanics test using the apparatus are also provided.

A system and method for monitoring crack propagation of a transparent rock specimen monitors a breakage process of a specimen loading process. In the system and method for monitoring crack propagation of a transparent rock specimen, under the condition of no contact with a rock specimen, intensity changes of laser light passing through the transparent rock specimen in a loading state are determined, such that a computer (5) forms, according to laser intensity change data, a three-dimensional diagram of crack propagation of the transparent rock specimen (4) in a continuously loaded state at a plurality of set time points. This is used to analyze a breakage starting point and a crack propagation path and process of the transparent rock specimen (4) in the loading state, and achieve the purpose of qualitative analysis of the rock specimen.

An improved system of monitoring vibration of a blasting model test for a jointed rock mass and a method are provided. The system includes: a loading subsystem for three-way load, a model-surface blasting-vibration acquisition subsystem, and a model-interior dynamic stress-strain acquisition subsystem. The system and the method are provided, and a blasting model for a transparent jointed rock mass and a monitoring method that are obtained can analyze the influence of a joint inclination angle on propagation and attenuation laws of blasting stress waves in the jointed rock mass, and can analyze the influence of different millisecond blasting modes on the stability of an existing tunnel in the jointed rock mass, and can capture a real-time dynamic evolution process of cracks. The stress and strain measurement technologies used can perform omnibearing monitoring and recording for large deformations of surrounding rock under blasting load, and can resist the electromagnetic interference.

Disclosed are an anisotropic mechanical expansion (anisotropic Poisson's ratio) substrate and a crack-based pressure sensor using the same. The substrate having an anisotropic Poisson's ratio includes a first layer having linear concave and convex patterns arranged in parallel to each other on a surface thereof; and a second layer having linear convex and concave patterns respectively engaged with the linear concave and convex patterns of the first layer on a surface thereof, wherein the first layer and the second layer are stacked with each other so that the linear convex and concave patterns of the second layer are respectively engaged with the linear concave and convex patterns of the first layer, wherein an elastic modulus of the first layer is different from an elastic modulus of the second layer.

A plate specimen is extracted from a qualified HIC resistant material having a Heat number. The plate specimen is supported on a female die of a guided bend system and a force is applied with a male die of the guided bend system to a predetermined middle portion of the plate specimen to develop a U-shaped bent portion in the plate specimen. A curved sample is extracted from the predetermined middle portion having the U-shaped bent portion, the curved sample simulates a cold forming ratio of a line pipe having a particular pipe diameter that is to be subsequently manufactured from the qualified Heat number. A standardized HIC test on the extracted curved sample. Respective values of Crack Length Ratio (CLR), Crack Sensitivity Ratio (CSR) and Crack Thickness Ratio (CTR) are calculated for the curved sample subsequent to the standardized HIC test on the curved sample. The qualified Heat number is validated for manufacturing the line pipe having the particular pipe diameter in response to determining that the calculated respective values of CLR, CSR, and CTR not greater than the corresponding predetermined maximum threshold values for the CLR, CSR, and CTR.

The present invention discloses a method for detecting the mechanical response of a mechanical component by an organic mechanoresponsive fluorescent material, comprising the following steps of: selecting an organic mechanoresponsive fluorescent material; preparing an organic mechanoresponsive fluorescent material solution; forming a film on a metal surface; calibrating fluorescence intensity and obtaining the fluorescence intensity and distribution in a crack tip area; observing the fluorescence signal generated at cracks to monitor the occurrence of fatigue cracks, and predict a propagation pathway of fatigue cracks by using the fluorescence intensity distribution in the crack tip area.

The present invention discloses a method for detecting the mechanical response of a mechanical component by an organic mechanoresponsive fluorescent material, comprising the following steps of: selecting an organic mechanoresponsive fluorescent material; preparing an organic mechanoresponsive fluorescent material solution; forming a film on a metal surface; calibrating fluorescence intensity and obtaining the fluorescence intensity and distribution in a crack tip area; observing the fluorescence signal generated at cracks to monitor the occurrence of fatigue cracks, and predict a propagation pathway of fatigue cracks by using the fluorescence intensity distribution in the crack tip area.

A system and a method evaluate the effect of proactive utilization of a spatial stress field in laboratory. The system includes a rock sample placement device for placing a rock sample, a confining pressure control device for applying a set confining pressure to the rock sample, a fracture imaging device, a fracturing fluid injection device for injecting fracturing fluid into the perforation in the wellbore of the rock sample to form fractures within the rock sample, a stress measurement device, and a processing device for calculating a stress field proactive utilization coefficient of the rock sample.

Described is a method for simulating the ageing of a predetermined fabric comprising the following steps: preparing two specimens of said predetermined fabric, subjecting said specimens to an abrasion process by mutual rubbing, subjecting a first of said specimens to a test by means of an Elmendorf type lacerometer according to the direction of the weft of said predetermined fabric, subjecting a second of said specimens to an Elmendorf test according to the direction of warp of said predetermined fabric, comparing the results of said Elmendorf tests with a reference value relative to an Elmendorf test performed on the same predetermined fabric not subjected to any abrasion process.

A testing system for causing a physical change in a crack tip region of a crack within a specimen. The testing system includes a load application system for applying a load to the specimen having the crack formed therein, an electrothermal system for applying an electrical current through the specimen and comprising a power supply and a controller operably coupled to the load application system and the electrothermal system. The load application system configured to perform a crack growth test on the specimen. A method of thermally influencing a crack tip region of a crack within a specimen includes applying at least one pulse of current to the specimen to generate flux tangentially around the crack within the specimen and at the crack tip region and causing the crack tip region of the crack within the specimen to reach a predetermined activation temperature.