Review of recent developments of spatial phase-shift digital shearography

Xie, Xin; Li, Xiaona; Xu, Chen; Yang, Lianxiang

doi:10.1117/12.2075536

Cited by 6 publications

(5 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An overall phase-shift value is determined from the fitted ellipsis for each interferogram, then the phase-shifted values are used to determine the phase value for each image pixel. In 2015, Xie et al provided a review of recent developments of spatial phase-shift digital shearography and specifically introduced the problem of improving the phase map quality of spatial phase-shift digital shearography [41]. In 2018, Aranchuk et al developed a pulsed digital shearography system that utilizes the spatial phase-shifting technique, which allows for instantaneous phase measurements [42].…”

Section: Michelson Basedmentioning

confidence: 99%

Digital Shearography for NDT: Phase Measurement Technique and Recent Developments

et al. 2018

Self Cite

View full text Add to dashboard Cite

Composite materials have seen widespread use in the aerospace industry and are becoming increasingly popular in the automotive industry due to their high strength and low weight characteristics. The increasing usage of composite materials has resulted in the need for more effective techniques for nondestructive testing (NDT) of composite structures. Of these techniques, digital shearography is one the most sensitive and accurate methods for NDT. Digital shearography can directly measure strain with high sensitivity when combined with different optical setups, phase-shift techniques, and algorithms. Its simple setup and less sensitivity to environmental disturbances make it particularly well suited for practical NDT applications. This paper provides a review of the phase measurement technique and recent developments in digital shearographic NDT. The introduction of new techniques has expanded the range of digital shearography applications and made it possible to measure larger fields and detect more directional or deeper defects. At the same time, shearography for different materials is also under research, including specular surface materials, metallic materials, etc. Through the discussion of recent developments, the future development trend of digital shearography is analyzed, and the potentials and limitations are demonstrated.

show abstract

Section: Michelson Basedmentioning

confidence: 99%

Digital Shearography for NDT: Phase Measurement Technique and Recent Developments

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…As a result, shearography can be effectively employed in field inspections, extending its application beyond laboratory environments, where its use has steadily increased. 1 in components of composite materials, accessing their integrity and quality Further author information: (Send correspondence to T.P.L.) T.P.L.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous orthogonal shearography using two pairs of parallel slits and a tetra-split lens

Lima

Barrera

Gonçalves

2023

Optical Measurement Systems for Industrial Inspection XIII

View full text Add to dashboard Cite

There are a growing number of industrial applications for shearography, especially in non-destructive testing of composite materials. Its tolerance to hostile environments is probably the most relevant success factor for industrial applications. The introduction of carrier fringes for phase recovery, replacing temporal phase shift techniques, allows measurements with a single exposure for each loading state, making shearography even more robust. Some defects are better evident when the shearing direction is horizontal. Others are best viewed with a vertical shearing direction. Thus, it is desirable to inspect in both directions. Fortunately, the literature reports some configurations capable of using carrier fringes to perform simultaneous measurements in more than one shearing direction. These systems work well, but since they use a mask with circular holes, they require a high amount of light. An alternative is the use of a pair of oblong slits, which increases the amount of light captured. This paper extends the use of oblong slit pairs for simultaneous measurement in two orthogonal shearing directions. Two pairs of parallel oblong slits are arranged orthogonally on the system mask. Although the Fourier transform of the resulting signal at the camera sensor contains the desired signals as well as a crosstalk between the slit pairs. However, the mask can be designed in such a way that the orthogonal signals are separable. To promote shearing in orthogonal directions, a polymeric lens was sectioned, forming four quadrants of 90°. The quadrants were radially displaced and arranged so that each oblong slit covers only one quadrant of the lens. As a result, four laterally shifted images are formed, two of them with horizontal shearing and the other two with vertical shearing. A proof-of-concept prototype was developed and the first results were evaluated by the authors in the laboratory environment and are presented in this article. The paper also shows details of the resulting Fourier spectrum and the strategy used to separate the orthogonal components and recover the phase using carrier fringes. The performance of the prototype met expectations and validated the concept. Future works involve miniaturization of the prototype and tests in industrial environments.

show abstract

“…Therefore, the temporal phase-shifting method performs well for static or quasi-static measurements. In contrast, the spatial carrier technique allows phase to be evaluated from a single shearogram, which allows dynamic measurement, a feature that has made the spatial carrier technique a focus of research interest [14,15].…”

Section: Introductionmentioning

confidence: 99%

Pixelated Carrier Phase-Shifting Shearography Using Spatiotemporal Low-Pass Filtering Algorithm

Yan

Liu

et al. 2019

Sensors

View full text Add to dashboard Cite

Shearography has been widely used in non-destructive testing due to its advantages in providing full-field, high precision, real-time measurement. The study presents a pixelated carrier phase-shifting shearography using a pixelated micropolarizer array. Based on the shearography, a series of shearograms are captured and phase maps corresponding to deformation are measured dynamically and continuously. Using the proposed spatiotemporal filtering algorithm in the complex domain, the set of phase maps are simultaneously low-pass filtered in the spatial and temporal domains, resulting in better phase quality than spatial low-pass filtering. By accumulating the temporally adjacent phase, the phase corresponding to large deformation can be evaluated; thus, large deformations can be accurately measured and protected from speckle noise, allowing internal defects to be easily identified. The capability of the proposed shearography is described by theoretical discussions and experiments.

show abstract

Review of recent developments of spatial phase-shift digital shearography

Cited by 6 publications

References 15 publications

Digital Shearography for NDT: Phase Measurement Technique and Recent Developments

Digital Shearography for NDT: Phase Measurement Technique and Recent Developments

Simultaneous orthogonal shearography using two pairs of parallel slits and a tetra-split lens

Pixelated Carrier Phase-Shifting Shearography Using Spatiotemporal Low-Pass Filtering Algorithm

Contact Info

Product

Resources

About