A strain distribution measurement system includes a tensile tester that deforms a test piece to measure mechanical properties of a material of the test piece, and a strain distribution measuring device that measures a strain distribution of the test piece. The strain distribution measuring device measures the strain distribution of the test piece based on a distribution of at least one of a reflectance or a polarization characteristic on the main face of the test piece.

A residual stress distribution measuring method of the present invention is characterized by comprising: by using an analytical model in which a cut-surface is interpolated to a cross section of a metal member, the step of calculating a residual force vector that is a sum of a load vector acting on a first metal piece at the cut-surface and a load vector acting on a second metal piece at the cut-surface; the step of calculating, as a modified displacement vector, an amount of movement at the cross section by interpolating the residual force vector as a forced load to the cross section of an analytical model of the metal member; by using an analytical model having the shape of a cut-surface of a measured first or second metal piece, the step of modifying the shape of the cut-surface of the first or the second metal piece on the basis of the calculated modified displacement vector; and by using the analytical model in which the shape of the cut-surface of the first or the second metal piece is modified, the step of calculating a residual stress distribution at the cross section by interpolating a forced displacement to the analytical model.

Disclosed are methods that, by not physically touching a material being measured, can measure the material's differential response quite accurately. A collimated light shines on the material under test, is reflected off it, and is then captured by a device that records the position where the reflected light is captured. This process is done both before and after the material is processed in some way (e.g., by applying a coat of paint). The change in position where the reflected light is captured is used in calculating the deflection of the material as induced b the process. This measured induced deflection is then used to accurately determinate the stress introduced into the material by the process. Other characteristics of the material under test, such as aspects of the material composition of a bi-metallic strip, for example, may also be determined from a deflection measurement.

The present disclosure relates to the technical field of non-destructive detecting of residual stress, and in particular to a non-destructive detecting device for component residual stress gradient. the non-destructive detecting device comprises: groups of transmitting transducers and receiving transducers arranged symmetrically to each other, the transmitting transducers closer to the symmetry axis have greater excitation frequencies; an acoustic wedge coupled to the groups of transmitting transducers and receiving transducers, wherein groups of cylindrical transmitting tunnels and receiving tunnels are provided obliquely within the transmitting connection area and the receiving connection area through their top surfaces and toward their bottom surfaces, the transmitting transducers are coupled to the transmitting tunnels in a one-to-one correspondence, the receiving transducers are coupled to the receiving tunnels in a one-to-one correspondence, and the bottom surfaces of the transmitting connection area and the receiving connection area are pressed against the surface of the detected component; and a calculation processing module electrically connected to the transmitting transducers and the receiving transducers. The non-destructive detecting device solves the problem that the residual stress values of components at different penetration depths cannot be detected at the same time.

Multi-film containers for use in additive fabrication devices are provided. According to some aspects, a container may include multiple films that are at least partially detached from one another. In some embodiments, the multiple films may include films formed from different materials. As one example, an upper film may be formed so as to be relatively impermeable to substances within a source material of an additive fabrication device, whereas a lower film may be formed so as to provide desirable mechanical properties. In some cases, the multiple films may be commonly tensioned while being unattached to one another.

A measurement system according to an aspect of the present invention enables measurement of an intensity distribution of diffracted X-rays obtained by irradiating a fillet portion of a metallic structure with X-rays, the metallic structure comprising: an axis portion; and a flange portion protruding radially from the axis portion, wherein the metallic structure comprises the fillet portion in a connection portion between the axis portion and the flange portion, the measurement system including: a diffracted X-rays measurement device provided with an irradiation unit that irradiates the fillet portion with X-rays; and a positioning device that positions the diffracted X-rays measurement device with respect to the fillet portion, in which the positioning device including: a moving mechanism that moves three-dimensionally the diffracted X-rays measurement device relative to the fillet portion; and a rotation mechanism that rotates the diffracted X-rays measurement device in such a direction that an angle of incidence of the X-rays with respect to the fillet portion is changed.

Disclosed are methods that, by not physically touching a material being measured, can measure the material's differential response quite accurately. A collimated light shines on the material under test, is reflected off it, and is then captured by a device that records the position where the reflected light is captured. This process is done both before and after the material is processed in some way (e.g., by applying a coat of paint). The change in position where the reflected light is captured is used in calculating the deflection of the material as induced by the process. This measured induced deflection is then used to accurately determinate the stress introduced into the material by the process. Other characteristics of the material under test, such as aspects of the material composition of a bi-metallic strip, for example, may also be determined from a deflection measurement.

A method for measuring a residual stress of a curved-surface bulk material includes steps of: locating a point at which a to-be-detected curved surface of a curved-surface bulk material has a highest curvature as a to-be-detected point; applying an instrument integrating an X-ray light resource and a detector, measuring the to-be-detected point by using an X-ray diffraction theory, and analyzing and calculating, in combination with a cos α method, a strain value measured by using the instrument; and calculating, in combination with material property measurement data of the curved-surface bulk material, a curved-surface residual stress by introducing a curved-surface bulk material residual stress calculation model.

Techniques for directing light from a movable stage in an additive fabrication device are provided. According to some aspects, the movable stage may include a parabolic mirror onto which light may be directed at various different incident angles to produce light along different positions along an axis. In some cases, this axis may be perpendicular to a direction of motion of the movable stage.

Techniques for force sensing in additive fabrication are provided. According to some aspects, an additive fabrication device may include a force sensor configured to measure a force applied to a build platform during fabrication. A length of time taken for a layer of material to separate from a surface other than the build platform to which it is adhered may be determined based on measurements from the force sensor. Subsequent additive fabrication operations, such as subsequent motion of the build platform, may be adapted based on the determined length of time.