An apparatus for testing the edge strength of a discrete sheet of material such as glass where the sheet has an irregular free-form shaped outline is disclosed. The apparatus can include a plurality of assemblies configured for selectively applying a 3-point bending load on an edge of the sheet of material in a test region of the apparatus, a detection mechanism that optically measures strain in the sheet of material in the region, and a processor that determines the stress in the sheet based on the measured strain by calculating the stress that would be required to produce the measured strain in the sheet of material.

The invention discloses a method for obtaining the geometrical and mechanical parameters of rock samples and a holographic scanning system thereof, wherein the system includes an observation mechanism, a multi-scale penetration mechanism, a grinding mechanism, a rock sample installation mechanism arranged on a three-axis precision motion platform, and an industrial computer controlling the operation mode of each mechanism of the platform Indentation/rotary penetration test, pulse echo signal acquisition, three-dimensional surface topography reconstruction, layer by layer grinding and repeated experiments are carried out. The geometric parameters and corresponding mechanical field parameters are obtained by spatial interpolation of the three-dimensional parameter lattice accumulated by several layers of single-layer rock parameters. The holographic scanning system and method can obtain the real spatial distribution of various media in rock samples. Combined with high performance numerical calculation method, it provides a more scientific method for the analysis of rock mechanical properties, failure and instability.

Disclosed herein is a method of inspecting a secondary bond of a laminated part. The method comprises positioning the laminated part within a sealed chamber. The method also comprises reducing a pressure within the sealed chamber to below a pressure outside the sealed chamber when the laminated part is positioned within the sealed chamber. The method further comprises, when the pressure within the sealed chamber is reduced to below the pressure outside the sealed chamber, measuring a gradient of change of a surface profile of the laminated part. The method additionally comprises determining a condition of the secondary bond based on the gradient of change of the surface profile of the laminated part.

An indenter is made of polycrystalline diamond and has a tip having a spherical surface with a radius of 10 to 2000 μm.

A digital image measurement device and method for the surface deformation of specimen based on sub-pixel corner detection is disclosed. This digital image measurement device is composed of a new type of image pressure cell, a complementary metal-oxide-semiconductor (CMOS) camera, a camera bracket, a flexible lens hood, a computer and matching measurement software. This method discretizes the specimen into several four-node finite elements by printing grids on the specimen and takes corners of the grids as the nodes of the finite elements; tracks the deformation of the feature points in real time by edge detection and corner detection based on sub-pixel; captures the deformation of the whole surface of the specimen by the two flat mirrors which are at an 120° angle behind the specimen; achieves the observation of the deformation of the whole surface by conducting splicing and error correction on the three images.

A miniature temperature-controlled triaxial tester for testing unsaturated soil suitable for micro-computer tomography (CT) scanning and a method thereby. The triaxial tester includes a device body, where the bottom of the device body is fixed on a base, and the top of the device body is provided with a strain control device. The device body includes a vertically arranged polymethyl methacrylate shell, a PMMA inner cover is nested inside the PMMA shell, and a vacuum gap is formed between the PMMA shell and the PMMA inner cover; a pressure cell is formed by a space defined by the PMMA inner cover, a sample accommodating area for accommodating a test sample is arranged in the pressure cell, a heating element is arranged below the sample accommodating area and connected to a temperature control device, and a temperature sensor is arranged inside the PMMA inner cover and connected to a receiver.

A hose to be evaluated is installed on a fixing frame in a preset shape, and a strain gauge and markers are attached to a surface of the hose. During a course of application of predetermined internal pressure to the hose, strain data is acquired using the strain gauge and an image of an external shape of the hose is captured using a camera device to acquire image data. Based on the strain data and the image data acquired, a change in the shape of the hose between a plurality of time points at identical internal pressure is determined. Such hose fatigue resistance evaluation method can determine changes in the degree of deformation of a hose over time due to repeated application of internal pressure.

A system for mechanical testing a specimen includes a 3D printed mechanical testing fixture; a linear actuator having an axis of movement; a controller configured to control the linear actuator; two cameras; a data-acquisition system configured to acquire data from the linear actuator, the controller, and the two cameras; and the specimen. The specimen is marked in two locations with tracking markers to provide indication to the data acquisition system via at least one camera of movement and change in length of the specimen. The fixture includes force-sensing beams extending perpendicular to the axis of force

A system for ultra-high temperature in-situ fretting fatigue experiment, includes a heat preservation cover defining a, a heating device arranged in the mounting space, a first test sample, a second test sample, and a clamping device arranged in the mounting space. The first test sample and the second test sample are arranged at an upper end of the heating device along a horizontal direction. A mortise is formed at an end of the first test sample facing towards the second test sample. A tenon mating with the mortise is formed at an end of the second test sample facing towards the first test sample. The clamping device is configured to be clamped at two ends of the mated first test sample and second test sample and to apply a periodically reciprocating loading along a length direction of the first test sample and the second test sample.

Analysis of residual stress in materials is often done in static conditions in a laboratory. Accurate systems and methods for performing these analyses in a dynamic, non-laboratory environment are notoriously difficult and can be very inaccurate. A method using a portable, field deployable apparatus having greater accuracy than currently available is disclosed whereby accurate and repeatable residual stress analysis may be implemented in non-laboratory environments leading to greatly improved diagnostics, maintenance and life limit prediction. Especially the analysis of a pipe or channel can be facilitated with this invention.