Method for confirming internal stress of resin and apparatus for measuring same
To provide an internal stress confirming method of a resin which is capable of measuring an internal stress of a translucent resin such as a fluororesin and a fluororubber and dynamically confirming stress propagation, and an apparatus measuring for the same. The internal stress confirming method for confirming an internal stress of a measurement target containing a translucent resin includes irradiating the measurement target with near-infrared light having a peak wavelength in a near-infrared band of 800 nm to 2500 nm through frosted glass, a polarizer, and a ¼ wavelength plate; acquiring a near-infrared image by imaging the measurement target through a ¼ wavelength plate and an analyzer; and confirming the internal stress of the measurement target based on the near-infrared image.
1 . An internal stress confirming method for confirming an internal stress of a measurement target containing a translucent resin, comprising:
irradiating the measurement target with near-infrared light having a peak wavelength in a near-infrared band of 800 nm to 2500 nm through a polarizer;
acquiring a near-infrared image by imaging the measurement target through an analyzer; and
confirming the internal stress of the measurement target based on the near-infrared image.
2 . The internal stress confirming method according to claim 1 , wherein a ¼ wavelength plate is provided between the analyzer and the measurement target.
3 . The internal stress confirming method according to claim 2 , wherein a ¼ wavelength plate is provided between the polarizer and the measurement target.
4 . The internal stress confirming method according to claim 1 , wherein frosted glass is provided between a near-infrared light source and the polarizer.
5 . The internal stress confirming method according to claim 1 , wherein the internal stress is confirmed while an external load is applied to the measurement target.
6 . The internal stress confirming method according to claim 1 , wherein a peak wavelength of the near-infrared light is 940 nm to 950 nm.
7 . The internal stress confirming method according to claim 1 , wherein the near-infrared image is a still image or a moving image.
8 . The internal stress confirming method according to claim 1 , wherein the translucent resin is a fluororesin or a fluororubber.
9 . The internal stress confirming method according to claim 1 , wherein the measurement target containing the translucent resin is any one of a tube of a piping material product, a sheet lining container, a tank component, a lining component, a square tank, an O-ring, a welded portion of a product, and a lining layer of a lining tank.
10 . An internal stress measuring apparatus for confirming an internal stress of a measurement target containing a translucent resin, comprising:
a near-infrared light source that irradiates the measurement target with near-infrared light having a peak wavelength in a near-infrared band of 800 nm to 2500 nm;
a near-infrared camera that detects near-infrared light transmitted through the measurement target and two-dimensionally images the measurement target; and
a computer that measures the internal stress of the measurement target based on a near-infrared image captured by the near-infrared camera,
wherein the measurement target is irradiated with the near-infrared light from the near-infrared light source through a polarizer, and
the near-infrared image is acquired by imaging the measurement target with the near-infrared camera through an analyzer.
11 . The internal stress measuring apparatus according to claim 10 , wherein a ¼ wavelength plate is provided between the analyzer and the measurement target.
12 . The internal stress measuring apparatus according to claim 11 , wherein a ¼ wavelength plate is provided between the polarizer and the measurement target.
13 . The internal stress measuring apparatus according to claim 10 , wherein frosted glass is provided between the near-infrared light source and the polarizer.
14 . The internal stress measuring apparatus according to claim 10 , further comprising: a mechanical strength measuring instrument that applies a load to the measurement target from the outside.
15 . The internal stress measuring apparatus according to claim 10 , wherein a peak wavelength of near-infrared light emitted from the near-infrared light source is 940 nm to 950 nm.
16 . The internal stress measuring apparatus according to claim 10 , wherein the near-infrared image captured by the near-infrared camera is a still image or a moving image.
17 . The internal stress measuring apparatus according to claim 10 , wherein the translucent resin is a fluororesin or a fluororubber.
18 . The internal stress measuring apparatus according to claim 10 , wherein the measurement target containing the translucent resin is any one of a tube of a piping material product, a sheet lining container, a tank component, a lining component, a square tank, an O-ring, a welded portion of a product, and a lining layer of a lining tank.