某弹体冷却历程下的变形与应变测量 - 新拓三维技术（深圳）有限公司

Deformation and strain measurement of a projectile during cooling process

Experiment summary

The digital image correlation method is used to study the measurement of deformation and strain of the propellant gain's outer surface during cooling time. In the experiment, two pairs of measuring heads were used to collect speckle images synchronously for 96 hours during the cooling process of the end and cylindrical surfaces of the two propellant gains from different perspectives. The data of deformation and strain field in more than 1800 states are obtained by calculation, and the data of deformation and strain are sampled, aligned and smoothed after denoising. Finally, the errors in the measurement process are discussed in view of the effects of noise and temperature expansion coefficient, camera temperature rise and room temperature change in one day.

Experimental process

According to the test requirements, a probe is set up on the corresponding measuring distance, and the acquisition time is 4 days (96 hours). The acquisition speed of the camera is determined to be 5 minutes. The measuring ranges of the measuring heads D and E are 1000mm*1000mm and 128mm*96mm, respectively. The speckle on the measured surface is sprayed, the focal length of the lens is

adjusted, the aperture is adjusted, and the system calibration is completed. The surface of the object is counted in real time by XTDIC system. According to collection. The figure below shows the measurementsite.

测量头E正视端面

Data analysis

The deformation of the four measuring planes of the grain is stable at 0.5-1 mm, and the maximum principal strain is 0.2%-0.25%. From the second and third stages, it can be seen that the deformation of the four planes has basically maintained a state of approximately sinusoidal superposition since 24 o'clock, and this trend becomes more obvious after 48 hours.