A sensing device capable of detecting hardness includes a sensor array including a plurality of sensors, each of the plurality of sensors including a transmitter configured to emit a detection wave and a receiver configured to receive a reflected detection wave reflected by an object, the plurality of sensors arranged in a matrix form; and a controller configured to obtain image information and hardness information of each portion of the object from the reflected waves received by the plurality of sensors, and to form three-dimensional print data by mapping the image information and the hardness information.

A sensing device capable of detecting hardness includes a sensor array including a plurality of sensors, each of the plurality of sensors including a transmitter configured to emit a detection wave and a receiver configured to receive a reflected detection wave reflected by an object, the plurality of sensors arranged in a matrix form; and a controller configured to obtain image information and hardness information of each portion of the object from the reflected waves received by the plurality of sensors, and to form three-dimensional print data by mapping the image information and the hardness information.

A method for measuring indentation resistance includes: obtaining a first curve indicating a yield shear stress in a depth direction of a raceway surface of a material forming a rolling bearing in a state before the raceway surface is subjected to machining, a second curve indicating a static shear stress in the depth direction of the raceway surface in a state in which the raceway surface is subjected to the machining, and a third curve indicating a static shear stress in the depth direction of the raceway surface in a state in which rolling elements are in contact with the raceway surface and a static load is applied to the raceway surface; and obtaining a correlation between an area and an indentation depth of the raceway ring by defining a region surrounded by exceeding the first curve and the second curve and falling below the third curve as the area.

A method for measuring indentation resistance includes: obtaining a first curve indicating a yield shear stress in a depth direction of a raceway surface of a material forming a rolling bearing in a state before the raceway surface is subjected to machining, a second curve indicating a static shear stress in the depth direction of the raceway surface in a state in which the raceway surface is subjected to the machining, and a third curve indicating a static shear stress in the depth direction of the raceway surface in a state in which rolling elements are in contact with the raceway surface and a static load is applied to the raceway surface; and obtaining a correlation between an area and an indentation depth of the raceway ring by defining a region surrounded by exceeding the first curve and the second curve and falling below the third curve as the area.

A calibration method for brittle fracture assessment parameters for pressure vessel materials based on the Beremin model includes selecting at least two types of specimens of different constraints, and calculating the fracture toughness values K.sub.0 corresponding to 63.2% failure probability for each type of specimens at a same calibration temperature by using the respective fracture toughness data. The method proceeds by obtaining the stress-strain curve of the material at the calibration temperature, generating finite element models for each type of specimens, and calculating the maximum principal stress and element volume of every element at K=K.sub.0 in each model. A series of values of m are assumed to compute a group of σ.sub.u values for each type of specimens, and then m˜σ.sub.u curves are plotted for each type of specimens. Brittle fracture assessment parameters are then determined for the material according to the coordinates of the intersection of the m˜σ.sub.u curves.

A calibration method for brittle fracture assessment parameters for pressure vessel materials based on the Beremin model includes selecting at least two types of specimens of different constraints, and calculating the fracture toughness values K.sub.0 corresponding to 63.2% failure probability for each type of specimens at a same calibration temperature by using the respective fracture toughness data. The method proceeds by obtaining the stress-strain curve of the material at the calibration temperature, generating finite element models for each type of specimens, and calculating the maximum principal stress and element volume of every element at K=K.sub.0 in each model. A series of values of m are assumed to compute a group of σ.sub.u values for each type of specimens, and then m˜σ.sub.u curves are plotted for each type of specimens. Brittle fracture assessment parameters are then determined for the material according to the coordinates of the intersection of the m˜σ.sub.u curves.

The method for evaluating the compactness of a layer of railroad ballast near a railroad tie includes at least one step of taking at least two measurements (11,11a,11b) of the penetration resistance (Qd) of the ballast (13) near one and the same railroad tie (10), and a step of calculating the mean value (Qd.sub.mean) of these measurements (11,11a,11b) of penetration resistance (Qd). Also provided are a device for implementing such a method and a method for predicting the settlement of the ballast of a railroad track including a step of evaluating the compactness of a ballast near a railroad tie.

The method for evaluating the compactness of a layer of railroad ballast near a railroad tie includes at least one step of taking at least two measurements (11,11a,11b) of the penetration resistance (Qd) of the ballast (13) near one and the same railroad tie (10), and a step of calculating the mean value (Qd.sub.mean) of these measurements (11,11a,11b) of penetration resistance (Qd). Also provided are a device for implementing such a method and a method for predicting the settlement of the ballast of a railroad track including a step of evaluating the compactness of a ballast near a railroad tie.

Provided herein is a method for measuring the size distribution and/or hardness of free falling rock pieces. The method comprises projecting at least one laser line on the falling rock pieces by a laser device; capturing images of the falling rock pieces at an angle from the at least one laser line by at least one camera; and obtaining size distribution data of the falling rock pieces based on data obtained from a topographical map generated from the captured images. Certain embodiments further comprise: obtaining at least one of the volume and area of individual rock pieces from the topographical map; conducting a data analysis on at least one of the volume and area measurements of the rock pieces to reduce at least one of sampling and measurement errors; determining the size distribution of the falling rock pieces based on the data analysis and, optionally, evaluating a rock hardness index for the rock. Further provided is a method comprising: producing two topographical maps of the pieces from captured images; and obtaining the volume of pieces from the topographical map by adding half-volumes from each of the topographical maps.

Provided herein is a method for measuring the size distribution and/or hardness of free falling rock pieces. The method comprises projecting at least one laser line on the falling rock pieces by a laser device; capturing images of the falling rock pieces at an angle from the at least one laser line by at least one camera; and obtaining size distribution data of the falling rock pieces based on data obtained from a topographical map generated from the captured images. Certain embodiments further comprise: obtaining at least one of the volume and area of individual rock pieces from the topographical map; conducting a data analysis on at least one of the volume and area measurements of the rock pieces to reduce at least one of sampling and measurement errors; determining the size distribution of the falling rock pieces based on the data analysis and, optionally, evaluating a rock hardness index for the rock. Further provided is a method comprising: producing two topographical maps of the pieces from captured images; and obtaining the volume of pieces from the topographical map by adding half-volumes from each of the topographical maps.