Dynamic impact deformation detection system based on digital holographic light path

Abstract

The utility model discloses a dynamic impact deformation detection system based on a digital holographic light path, and belongs to the technical field of digital holographic detection. The laser device emits laser to the beam splitter, the beam splitter divides a laser beam into a reference beam and an object beam, the object beam sequentially passes through the first beam expander, the first spatial filter, the first collimating lens and the beam combiner and then irradiates an object to be measured, and the object to be measured reflects the object beam carrying information to the beam combiner. A reference light beam sequentially passes through a first total reflective mirror, a second total reflective mirror, a second beam expander, a second spatial filter and a second collimating lens and then reaches a beam combiner, and an object light beam carrying information and the reference light beam are combined in the beam combiner and interfere with each other. The high-speed camera shoots the hologram of the object to be detected and transmits the hologram to the digital processing system for processing, so that the dynamic impact deformation detection of the object to be detected is realized, the detection resolution and precision are improved, and a more reliable and comprehensive detection result is obtained.

Description

Technical Field

[0001] The utility model belongs to the technical field of digital holographic detection, and relates to a dynamic impact deformation detection system based on a digital holographic optical path. Background Art

[0002] During actual use, materials will be subjected to dynamic impact due to the needs of specific usage scenarios. Under the action of dynamic impact loads, the materials will deform. The research on the dynamic impact deformation of materials directly affects the specific use process of the materials. Therefore, it is necessary to test the dynamic impact deformation of materials to provide support for subsequent research.

[0003] At present, dynamic impact deformation detection of materials mainly relies on mechanical and electrical sensors. However, the resolution and accuracy of the above sensors are limited at high strain rates, which makes it difficult to meet the needs of high-precision material research and engineering applications.

[0004] Therefore, it is necessary to provide a dynamic impact deformation detection system based on digital holographic optical path to improve the resolution and detection accuracy during the dynamic impact deformation detection process of materials and obtain high-precision dynamic impact deformation detection results.

[0005] As a non-contact, high-resolution optical measurement technology, digital holographic measurement technology has great application potential. Applying digital holographic technology to dynamic impact deformation detection can significantly improve measurement accuracy and real-time performance, so as to overcome the defects of insufficient resolution and accuracy of existing technologies under high strain rate conditions. The system can measure the surface deformation and displacement changes of material samples in real time during the Hopkinson bar impact experiment, thereby obtaining a high-precision dynamic stress-strain relationship. Utility Model Content

[0006] In order to overcome the problems in the background technology, the utility model proposes a dynamic impact deformation detection system based on a digital holographic optical path, which utilizes the non-contact characteristics of the digital holographic optical path to avoid the detection system from contacting the object to be detected and introducing errors, thereby improving the detection accuracy. At the same time, the digital holographic optical path has high resolution, which helps to improve the detection resolution and detection accuracy.

[0007] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0008] The detection system comprises a laser 1, a beam splitter 2, a first total reflection mirror 3, a second total reflection mirror 4, a first beam expander 5, a second beam expander 6, a first spatial filter 7, a second spatial filter 8, a first collimating lens 9, a second collimating lens 10, a beam combiner 11, a high-speed camera 12, and a digital processing system 13. The laser 1 emits laser light to the beam splitter 2, and the beam splitter 2 splits the laser beam into a reference beam and an object beam.

[0009] The object beam passes through the first beam expander 5, the first spatial filter 7, the first collimating lens 9, and the beam combiner 11 in sequence, and then irradiates the object 14 to be measured. The object 14 to be measured reflects the object beam carrying information to the beam combiner 11.

[0010] The reference beam passes through the first total reflection mirror 3, the second total reflection mirror 4, the second beam expander 6, the second spatial filter 8, and the second collimating lens 10 in sequence and then reaches the beam combiner 11. After the object beam carrying information and the reference beam are combined and interfere with each other in the beam combiner 11, they reach the high-speed camera 12. The high-speed camera 12 captures a hologram of the object to be measured 14. The high-speed camera 12 is communicatively connected to the digital processing system 13.

[0011] Preferably, the laser 1 is a helium-neon laser.

[0012] Preferably, the digital processing system 13 comprises a computer.

[0013] Preferably, the object to be measured 14 and the beam combiner 11 are located at the same height.

[0014] Beneficial effects of the utility model:

[0015] 1. The utility model detects the dynamic impact deformation of materials by using a digital holographic optical path detection system, thereby improving the detection resolution and accuracy, obtaining high-precision detection results, providing more reliable data support for subsequent research on the mechanical properties of materials, and promoting the development of research on the mechanical properties of materials.

[0016] 2. The utility model uses a digital holographic optical path detection system to perform real-time detection of the dynamic impact deformation of materials, thereby obtaining more comprehensive data and providing a more complete data basis for subsequent research on the mechanical properties of materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the detection system of the utility model.

[0018] Figure 2 Schematic diagram of light reflected by the object to be measured.

[0019] In the figure, 1-laser, 2-beam splitter, 3-first total reflection mirror, 4-second total reflection mirror, 5-first beam expander, 6-second beam expander, 7-first spatial filter, 8-second spatial filter, 9-first collimating lens, 10-second collimating lens, 11-beam combiner, 12-high-speed camera, 13-digital processing system, 14-object to be measured. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with specific embodiments.

[0021] The embodiment of the utility model uses the detection system in the Hopkinson pressure bar experiment process. The Hopkinson pressure bar experiment is the most widely used experimental technology in the research of material dynamic performance.

[0022] like Figure 1-2 As shown, the detection system includes a laser 1, a beam splitter 2, a first total reflection mirror 3, a second total reflection mirror 4, a first beam expander 5, a second beam expander 6, a first spatial filter 7, a second spatial filter 8, a first collimating lens 9, a second collimating lens 10, a beam combiner 11, a high-speed camera 12, and a digital processing system 13. The laser 1 emits laser to the beam splitter 2, and the beam splitter 2 splits the laser beam into a reference beam and an object beam.

[0023] The object beam passes through the first beam expander 5 , the first spatial filter 7 , the first collimating lens 9 , and the beam combiner 11 in sequence, and then irradiates the object 14 to be measured. The object 14 to be measured reflects the object beam carrying information to the beam combiner 11 .

[0024] The reference beam passes through the first total reflection mirror 3, the second total reflection mirror 4, the second beam expander 6, the second spatial filter 8, and the second collimating lens 10 in sequence and then reaches the beam combiner 11. After the object beam carrying information and the reference beam are combined and interfere with each other in the beam combiner 11, they reach the high-speed camera 12. The high-speed camera 12 captures a hologram of the object to be measured 14. The high-speed camera 12 is communicatively connected to the digital processing system 13.

[0025] The laser 1 is a helium-neon laser.

[0026] The digital processing system 13 includes a computer.

[0027] The object to be measured 14 and the beam combiner 11 are located at the same height.

[0028] After the laser 1 emits the laser, it is divided into an object beam and a reference beam at the beam splitter 2. The object beam passes through the first beam expander 5 and the first spatial filter 7 in sequence, so that the plane wave becomes a spherical wave, and then the high-frequency stray light is filtered out. Then the object beam passes through the first collimating lens 9 and irradiates the object to be measured 14. After the beam contacts the object to be measured 14, the information of the object to be measured 14 can be obtained. After that, when the object beam is reflected by the object to be measured 14 to the beam combiner 11, the object beam carrying the information of the object to be measured 14 and the reference beam are combined at the beam combiner 11 and interfere with each other. Then, the high-speed camera 12 can take a hologram of the object to be measured 14 and transmit the hologram to the digital processing system 13. After the digital processing system 13 processes the hologram, the dynamic impact deformation detection result of the object to be measured 14 can be obtained.

[0029] The principle of data processing by the digital processing system 13 is:

[0030] When the object 14 to be measured is not subjected to dynamic impact, it is not deformed. At this time, the object beam light field after the laser emitted by the laser 1 and split by the beam splitter 2 is O(x, y). After the object beam reaches the object 14 to be measured, the object beam light field reflected by the object 14 to the beam combiner 11 is O1(x, y). After the reference beam split by the beam splitter 2 passes through the second beam expander 6, the second spatial filter 8, and the second collimating lens 10, the light field reaching the beam combiner 11 is R(x, y).

[0031] When the object to be measured 14 is not deformed, the high-speed camera 12 captures an initial hologram, and the grayscale distribution of the initial hologram fringes is as follows:

[0032] I(x,y)=(O(x,y) 2 +R(x,y) 2 )+O1(x,y)R * (x,y)+O1 * (x,y)R(x,y)

[0033] Among them, R * (x,y) is the complex conjugate function of R(x,y), O * 1(x,y) is the complex conjugate function of O1(x,y).

[0034] The digital processing system 13 digitally reproduces the grayscale distribution diagram of the initial hologram fringe to obtain the original complex light field U1 of the object to be measured 14:

[0035]

[0036] Among them, A1 is the original complex light field amplitude, j is an imaginary number, is the original complex light field phase.

[0037] Then, the Hopkinson pressure bar test equipment is turned on to impact the object 14 to be tested. After the object 14 to be tested is impacted, it is deformed. At this time, the high-speed camera 12 captures the impact hologram, and the grayscale distribution of the impact hologram fringes also satisfies the formula:

[0038] I(x,y)=(O(x,y) 2 +R(x,y) 2 )+O1(x,y)R * (x,y)+O1 * (x,y)R(x,y)

[0039] The digital processing system digitally reproduces the grayscale distribution diagram of the impact hologram fringe to obtain the complex light field U2 after the object 14 to be tested is impacted:

[0040]

[0041] Among them, A2 is the amplitude of the complex light field after the object to be measured is impacted, It is the phase of the complex light field after the object to be measured is impacted.

[0042] The complex light field U2 of the object 14 to be tested after being impacted is divided by the original complex light field U1 to obtain the complex light field U:

[0043]

[0044] Take the phase angle of the complex light field U and calculate the deformation field wrapping phase The expression is:

[0045]

[0046] Wrap the deformation field around the phase Unwrap and obtain the real phase change of the object 14 before and after the impact, that is, the deformation field

[0047]

[0048] Using the deformation field and the laser wavelength, the displacement change Δz of the object from the surface is calculated:

[0049]

[0050] Here, λ is the laser wavelength.

[0051] The high-speed camera 12 captures the hologram of the object 14 to be tested before and after the impact. After receiving the hologram, the digital processing system 13 directly calculates the result according to its built-in program. The above principles are all common knowledge in the art.

[0052] The working process of the utility model is as follows: when it is necessary to detect the dynamic impact deformation of the object to be tested, the object to be tested is first mounted on the impact load loading device, and then the height of the object to be tested is adjusted to be consistent with the height of the beam combining mirror, after which the laser is turned on to emit laser, a high-speed camera takes a hologram of the object to be tested before the impact and transmits it to a digital processing system for processing, and then the impact load loading device is turned on, the object to be tested is deformed by the impact, a high-speed camera takes a hologram of the object to be tested after the impact and transmits it to a digital processing system for processing, and finally the digital processing system directly outputs the calculation results, and the calculation results are combined with parameters such as the loading load and loading time of the impact load loading device, so as to evaluate the mechanical properties of the object to be tested.

[0053] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the utility model.

Claims

1. A dynamic impact deformation detection system based on digital holographic optical path, characterized in that: The detection system comprises a laser (1), a beam splitter (2), a first total reflection mirror (3), a second total reflection mirror (4), a first beam expander (5), a second beam expander (6), a first spatial filter (7), a second spatial filter (8), a first collimating lens (9), a second collimating lens (10), a beam combiner (11), a high-speed camera (12), and a digital processing system (13). The laser (1) emits laser light to the beam splitter (2), and the beam splitter (2) splits the laser light beam into a reference light beam and an object light beam. The object light beam passes through a first beam expander (5), a first spatial filter (7), a first collimating lens (9), and a beam combiner (11) in sequence, and then irradiates an object to be measured (14), and the object to be measured (14) reflects the object light beam carrying information to the beam combiner (11); The reference light beam passes through a first total reflection mirror (3), a second total reflection mirror (4), a second beam expander (6), a second spatial filter (8), and a second collimating lens (10) in sequence before reaching a beam combiner (11). After the object light beam carrying information and the reference light beam are combined and interfere with each other in the beam combiner (11), they reach a high-speed camera (12). The high-speed camera (12) captures a hologram of the object to be measured (14). The high-speed camera (12) is in communication connection with a digital processing system (13).

2. According to claim 1, a dynamic impact deformation detection system based on digital holographic optical path is characterized in that: The laser (1) is a helium-neon laser.

3. The dynamic impact deformation detection system based on digital holographic optical path according to claim 1 is characterized in that: The digital processing system (13) includes a computer.

4. The dynamic impact deformation detection system based on digital holographic optical path according to claim 1 is characterized in that: The object to be measured (14) and the beam combining mirror (11) are located at the same height.

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