Stress distribution measurement method and stress distribution measurement system

1. A stress distribution measurement method of measuring stress distribution generated on a structural object including two support parts and a beam part provided between the support parts when a moving object moves along the structural object, the method comprising:

generating first image data by performing, through a first image capturing unit, image capturing of the moving object moving between the support parts or an identification display object attached to the structural object;

calculating, based on the first image data, a movement duration in which the moving object moves between the support parts of the structural object;

generating, as second image data, thermal image data in accordance with temperature at a surface of the beam part of the structural object by performing image capturing of the surface of the beam part through a second image capturing unit;

calculating a temperature change amount based on a second image data group corresponding to the movement duration in the second image data; and

calculating a stress change amount based on the temperature change amount to calculate stress distribution generated on the surface of the beam part of the structural object based on the stress change amount.

2. The stress distribution measurement method according to claim 1 , wherein, in calculating the temperature change amount, the temperature change amount is calculated through Fourier transform of the second image data group.

3. The stress distribution measurement method according to claim 1 , wherein, in calculating the temperature change amount, the temperature change amount is calculated from temperature change along with temporal change of the second image data group in a specific range.

4. The stress distribution measurement method according to claim 1 , wherein, in calculating the movement duration, the movement duration is calculated by calculating the position of the moving object relative to the support parts of the structural object based on the size of an accessory of the moving object.

5. The stress distribution measurement method according to claim 1 , wherein, in calculating the movement duration, the movement duration is calculated by calculating the position of the moving object relative to the support parts of the structural object based on the distance between the first image capturing unit and the moving object.

6. The stress distribution measurement method according to claim 1 , wherein, in generating the second image data, no image capturing of the surface of the beam part of the structural object is performed except for the movement duration.

7. The stress distribution measurement method according to claim 1 , wherein the second image capturing unit is an infrared camera.

8. The stress distribution measurement method according to claim 1 , wherein the first image capturing unit is a visible light camera.

9. The stress distribution measurement method according to claim 1 , wherein

the first image data and the second image data each include a plurality of frames,

in calculating the movement duration,

frames including images of the respective identification display objects of the two support parts are specified as start and end frames of the movement duration in the first image data from among the plurality of frames of the first image data, and

start and end frames of the movement duration in the second image data are specified from among the plurality of frames of the second image data based on the specified start and end frames in the first image data.

10. The stress distribution measurement method according to claim 9 , wherein times at which the moving object passes through the two respective support parts are specified based on the specified start and end frames in the first image data, and start and end frames of the movement duration in the second image data are specified from among the plurality of frames of the second image data based on the specified time.

11. The stress distribution measurement method according to claim 9 , wherein frames which the second image capturing unit makes by image capturing when the start and end frames in the first image data are specified are specified as start and end frames of the movement duration in the second image data.

12. A stress distribution measurement system configured to measure stress distribution generated on a structural object including two support parts and a beam part provided between the support parts when a moving object moves along the structural object, the system comprising:

a first image capturing unit configured to generate first image data by performing image capturing of the moving object moving between the support parts or an identification display object attached to the structural object from the moving object;

a second image capturing unit configured to generate, as second image data, thermal image data in accordance with temperature at a surface of the beam part of the structural object by performing image capturing of the surface of the beam part;

a first calculation unit configured to calculate, based on the first image data, a movement duration in which the moving object moves between the support parts of the structural object;

a second calculation unit configured to calculate a temperature change amount based on a second image data group corresponding to the movement duration in the second image data; and

a third calculation unit configured to calculate a stress change amount based on the temperature change amount and calculate stress distribution generated on the surface of the beam part of the structural object based on the stress change amount.