Strategy for Crack Width Measurement of Multiple Crack Patterns in Civil Engineering Material Testing Using a Monocular Image Sequence Analysis

Liebold, Frank; Maas, Hans‐Gerd

doi:10.1007/s41064-020-00103-2

Cited by 13 publications

(21 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[ 17 ]. It has been described in detail by Liebold and Maas [ 18 , 19 , 20 ] and is briefly summarized here. We limit ourselves to the analysis of specimens with planar surfaces as recorded by monocular image sequences.…”

Section: Photogrammetric Techniques For Crack Detection and Crack mentioning

confidence: 99%

“…Triangles with cracks penetrating them entirely show significant deformations, while the remaining triangles are unchanged. For that purpose, the relative translation vector

can be computed for each triangle based on the relative movement of its vertices [ 19 , 20 ]. Figure 2 a schematically depicts a divided triangle used as the assumed model for the computation of the relative translation vector.…”

Section: Photogrammetric Techniques For Crack Detection and Crack mentioning

confidence: 99%

“…Furthermore, it is also possible to derive crack widths and crack opening vectors for deformed crack triangles with the help of the relative translation vector

as shown by Liebold and Maas [ 19 , 20 ]. Crack widths can be computed as the projection of the relative translation vector

onto the crack normal

, which has to be determined first; see Figure 4 a.…”

Section: Photogrammetric Techniques For Crack Detection and Crack mentioning

confidence: 99%

“… ( a ) The crack width r is computed by the projection of

onto the normal

; ( b ) crack normal estimation according to [ 19 , 20 ]. …”

Section: Figurementioning

confidence: 99%

See 3 more Smart Citations

Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

et al. 2020

View full text Add to dashboard Cite

The determination of crack propagation velocities can provide valuable information for a better understanding of damage processes of concrete. The spatio-temporal analysis of crack patterns developing at a speed of several hundred meters per second is a rather challenging task. In the paper, a photogrammetric procedure for the determination of crack propagation velocities in concrete specimens using high-speed camera image sequences is presented. A cascaded image sequence processing which starts with the computation of displacement vector fields for a dense pattern of points on the specimen’s surface between consecutive time steps of the image sequence chain has been developed. These surface points are triangulated into a mesh, and as representations of cracks, discontinuities in the displacement vector fields are found by a deformation analysis applied to all triangles of the mesh. Connected components of the deformed triangles are computed using region-growing techniques. Then, the crack tips are determined using the principal component analysis. The tips are tracked in the image sequence and the velocities between the time stamps of the images are derived. A major advantage of this method as compared to the established techniques is in the fact that it allows spatio-temporally resolved, full-field measurements rather than point-wise measurements. Furthermore, information on the crack width can be obtained simultaneously. To validate the experimentation, the authors processed image sequences of tests on four compact-tension specimens performed on a split-Hopkinson tension bar. The images were taken by a high-speed camera at a frame rate of 160,000 images per second. By applying the developed image sequence processing procedure to these datasets, crack propagation velocities of about 800 m/s were determined with a precision in the order of 50 m/s.

show abstract

Section: Photogrammetric Techniques For Crack Detection and Crack mentioning

confidence: 99%

“…Triangles with cracks penetrating them entirely show significant deformations, while the remaining triangles are unchanged. For that purpose, the relative translation vector

Section: Photogrammetric Techniques For Crack Detection and Crack mentioning

confidence: 99%

“…Furthermore, it is also possible to derive crack widths and crack opening vectors for deformed crack triangles with the help of the relative translation vector

as shown by Liebold and Maas [ 19 , 20 ]. Crack widths can be computed as the projection of the relative translation vector

onto the crack normal

, which has to be determined first; see Figure 4 a.…”

Section: Photogrammetric Techniques For Crack Detection and Crack mentioning

confidence: 99%

“… ( a ) The crack width r is computed by the projection of

onto the normal

; ( b ) crack normal estimation according to [ 19 , 20 ]. …”

Section: Figurementioning

confidence: 99%

See 2 more Smart Citations

Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The image sequence processing chain, which is used for crack detection and crack measurement in the work presented here, bears the name 'cascaded image analysis' in [17]. It has been described in detail by Liebold and Maas [18][19][20] and is briefly summarized here. We limit ourselves to the analysis of specimens with planar surfaces as recorded by monocular image sequences.…”

Section: Photogrammetric Techniques For Crack Detection and Crack Widmentioning

confidence: 99%

Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

Liebold

Heravi

Mosig

et al. 2020

Preprint

View full text Add to dashboard Cite

The determination of crack propagation velocities can provide valuable information for a better understanding of damage processes of concrete. The spatio-temporal analysis of crack patterns developing at a speed of several hundred meters per second is a rather challenging task. In the paper, a photogrammetric procedure for the determination of crack propagation velocities in concrete specimens using high-speed camera image sequences is presented. A cascaded image sequence processing which starts with the computation of displacement vector fields for a dense pattern of points on the specimen’s surface between consecutive time steps of the image sequence chain has been developed. These surface points are triangulated into a mesh, and as representations of cracks, discontinuities in the displacement vector fields are found by a deformation analysis applied to all triangles of the mesh. Connected components of the deformed triangles are computed using region-growing techniques. Then, the crack tips are determined using principal component analysis. The tips are tracked in the image sequence and the velocities between the time stamps of the images are derived. A major advantage of this method as compared to established techniques is in the fact of its allowing for spatio-temporally resolved, full-field measurements rather than point-wise measurements and that information on crack width can be obtained simultaneously. To validate the experimentation, the authors processed image sequences of tests on four compact-tension specimens performed on a split-Hopkinson tension bar. The images were taken by a high-speed camera at a frame rate of 160,000 images per second. By applying to these datasets the image sequence processing procedure as developed, crack propagation velocities of about 800 m/s were determined with a precision in the order of 50 m/s.

show abstract

Impaktsicherheit von Baukonstruktionen durch mineralisch gebundene Komposite: Bauteilebene

Hering

Scheerer

Curbach

et al. 2020

Beton und Stahlbetonbau

View full text Add to dashboard Cite

Ziel des seit 2017 durch die Deutsche Forschungsgemeinschaft (DFG) geförderten Graduiertenkollegs GRK 2250 ist die interdisziplinäre Erforschung von Methoden zur Erhöhung des Impaktwiderstands von Bauwerken durch nachträgliche Verstärkung. Der vorliegende Beitrag gibt einen Einblick in die GRK‐Forschung auf Strukturebene. Mineralisch gebundene Verstärkungsschichten wurden auf der dem Impakt abgewandten Bauteilseite untersucht. Als Material für diese Schichten kamen feinkörnige Matrices ohne und mit Kurzfasern zur Anwendung, deren Wirksamkeit in der Impaktverstärkung durch die Einbettung verschiedener Textilien variiert wurde. Derartig verstärkte Platten wurden in einer Fallturmanlage einer Impaktbelastung ausgesetzt. Ein wichtiger Indikator für die Effektivität einer Verstärkungsmethode ist die Beurteilung der Schädigung. Hierzu wurde unter anderem eine Methode zur Analyse von Rissmustern durch Bildsequenzanalyse entwickelt. Die Experimente dienten des Weiteren als Referenz für die Simulation der Rissausbreitung in den impaktbeanspruchten Bauteilen mit der Phasenfeldmethode.

show abstract

Strategy for Crack Width Measurement of Multiple Crack Patterns in Civil Engineering Material Testing Using a Monocular Image Sequence Analysis

Cited by 13 publications

References 18 publications

Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

Impaktsicherheit von Baukonstruktionen durch mineralisch gebundene Komposite: Bauteilebene

Contact Info

Product

Resources

About