Out-of-Plane Deformation Measurement of Soft Solid Using a Stereo Camera System

2018 ◽  
Vol 382 ◽  
pp. 218-222
Author(s):  
Jonas A. Pramudita ◽  
Toshiki Isawa ◽  
Yuji Tanabe
Keyword(s):  
Deformation Behavior ◽  
Mechanical Characteristics ◽  
Plane Deformation ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
External Loading ◽  
Camera System ◽  
Stereo Camera ◽  
Isoparametric Finite Element ◽  
Out Of Plane

Soft solid undergoes large deformation under external loading. In order to understand the mechanical characteristics of soft solid, a quantitative evaluation of the deformation behavior is necessary. In the previous study, a strain distribution on the surface of soft solid during an indentation (penetration) test was obtained by evaluating the deformation behavior using isoparametric finite element. However, three-dimensional deformations including out-of-plane deformation was neglected. In this study, the deformation behavior of the soft solid was analyzed using a stereo camera system and binocular disparity method. The out-of-plane deformation of the soft solid was then reconstructed three-dimensionally. Analysis result showed that this study was able to reconstruct the out-of-plane deformation in the area below the indenter. In addition, the displacements of specific points located on the deformed surface could also be estimated. Under the indentation loading condition, the out-of-plane displacements of points in the area below the indenter were estimated to be between 5.9 and 9.9 mm. However, the accuracy of the estimation should be validated by other measurement techniques in the future.

scholarly journals In-Process Measurement of Three-Dimensional Deformations Based on Speckle Photography

2021 ◽  
Vol 11 (11) ◽  
pp. 4981
Author(s):  
Andreas Tausendfreund ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
Evaluation Method ◽  
Process Analysis ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Machining Process ◽  
Image Correlation ◽  
Speckle Photography ◽  
Process Measurement ◽  
Out Of Plane ◽  
Plane Deformations

In the concept of the process signature, the relationship between a material load and the modification remaining in the workpiece is used to better understand and optimize manufacturing processes. The basic prerequisite for this is to be able to measure the loads occurring during the machining process in the form of mechanical deformations. Speckle photography is suitable for this in-process measurement task and is already used in a variety of ways for in-plane deformation measurements. The shortcoming of this fast and robust measurement technique based on image correlation techniques is that out-of-plane deformations in the direction of the measurement system cannot be detected and increases the measurement error of in-plane deformations. In this paper, we investigate a method that infers local out-of-plane motions of the workpiece surface from the decorrelation of speckle patterns and is thus able to reconstruct three-dimensional deformation fields. The implementation of the evaluation method enables a fast reconstruction of 3D deformation fields, so that the in-process capability remains given. First measurements in a deep rolling process show that dynamic deformations underneath the die can be captured and demonstrate the suitability of the speckle method for manufacturing process analysis.

scholarly journals Resonance Raman spectroscopic examination of ferrochelatase-induced porphyrin distortion

2011 ◽  
Vol 15 (05n06) ◽  
pp. 357-363 ◽  
Author(s):  
Ricardo Franco ◽  
Salam Al-Karadaghi ◽  
Gloria C. Ferreira
Keyword(s):  
Catalytic Mechanism ◽  
Plane Deformation ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Protoporphyrin Ix ◽  
Three Dimensional ◽  
Normal Structure ◽  
Raman Spectroscopic ◽  
Out Of Plane ◽  
Structure Decomposition

Ferrochelatase, the terminal enzyme of the heme biosynthetic pathway, catalyzes the insertion of ferrous iron into protoporphyrin IX to give heme. Resonance Raman spectroscopy has been instrumental in defining the distortion (mode and extent) of the porphyrin substrate, which is a critical step in the catalytic mechanism of ferrochelatase. Saddling is the predominant porphyrin out-of-plane deformation induced upon binding to ferrochelatase. Our analysis demonstrated that the intensity of the γ15 line, which is assigned to an out-of-plane porphyrin vibration, in resonance Raman spectra obtained for wild-type- and variant ferrochelatase-bound porphyrin, correlates with the saddling deformation undergone by the porphyrin substrate. Further analysis of the three dimensional X-ray structures of bacterial, human and yeast ferrochelatases and the type and extent of distortion of the protein-bound porphyrin substrate and inhibitors using normal structure decomposition, support the view that ferrochelatase catalysis involves binding of a distorted porphyrin substrate and releasing of a flatter, metalated porphyrin.

Anisotropic Deformation Behavior of Porous Polymeric Membranes Under Uni-Axial and Bi-Axial Loadings

2019 ◽  
Author(s):  
Kanako Emori ◽  
Akio Yonezu ◽  
Takumi Nagakura ◽  
Tatsuma Miura
Keyword(s):  
Deformation Behavior ◽  
Biaxial Loading ◽  
Tensile Deformation ◽  
Cell Structure ◽  
Plane Deformation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Displacement Curve ◽  
Out Of Plane ◽  
Anisotropic Deformation

Abstract This study systematically investigates the uniaxial and biaxial tensile deformation behavior of polytetrafluoroethylene (PTFE) membranes which are used for water purification. The present PTFE membrane has micron size pores with open cell structure, and the pore is anisotropic shape. During the uniaxial tensile test, the membranes undergo elastic deformation and plastic deformation with strain rate sensitivity (i.e. time-dependent deformation behavior). In addition, it strongly demonstrates anisotropic deformation, i.e. deformation behavior is different along longitudinal direction and transverse ones. To clarify the microscopic deformation mechanism, in-situ SEM observation is carried out during tensile loading. It is found that the anisotropic deformation behavior appears due to the inherent pore structure. Next, to investigate deformation behavior under biaxial loading condition, small punch test using a spherical indenter is carried out. The membrane undergoes elastic and plastic deformations. Finally, crack nucleates around the indenter contact and indenter completely penetrates through the membrane. It is also found that the membrane demonstrates anisotropic out-of-plane deformation behavior. To clarify these mechanisms, FEM computation is carried out, such that experimental results of force-displacement curve and out-of-plane deformation behavior are compared with the computational ones. The present FEM model enables the prediction of the membrane’s deformation behavior under biaxial loading.

scholarly journals Epithelial tissue folding pattern in confined geometry

2019 ◽  
Vol 19 (3) ◽  
pp. 815-822 ◽  
Author(s):  
Yasuhiro Inoue ◽  
Itsuki Tateo ◽  
Taiji Adachi
Keyword(s):  
Plane Deformation ◽  
Three Dimensional ◽  
Epithelial Tissue ◽  
Mechanical Behaviors ◽  
Confined Geometry ◽  
Folding Pattern ◽  
Out Of Plane ◽  
Dimensional Shape ◽  
Tissue Deformations ◽  
Three Dimensional Shape

AbstractThe primordium of the exoskeleton of an insect is epithelial tissue with characteristic patterns of folds. As the insect develops from larva to pupa, the spreading of these folds produces the three-dimensional shape of the exoskeleton of the insect. It is known that the three-dimensional exoskeleton shape has already been encoded in characteristic patterns of folds in the primordium; however, a description of how the epithelial tissue forms with the characteristic patterns of folds remains elusive. The present paper suggests a possible mechanism for the formation of the folding pattern. During the primordium development, because of the epithelial tissue is surrounded by other tissues, cell proliferation proceeds within a confined geometry. To elucidate the mechanics of the folding of the epithelial tissue in the confined geometry, we employ a three-dimensional vertex model that expresses tissue deformations based on cell mechanical behaviors and apply the model to examine the effects of cell divisions and the confined geometry on epithelial folding. Our simulation results suggest that the orientation of the axis of cell division is sufficient to cause different folding patterns in silico and that the restraint of out-of-plane deformation due to the confined geometry determines the interspacing of the folds.

scholarly journals Scanning stereo-PLIF method for free surface measurements in large 3D domains

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Mike van Meerkerk ◽  
C. Poelma ◽  
J. Westerweel
Keyword(s):  
Free Surface ◽  
Three Dimensional ◽  
Light Sheet ◽  
Calibration Procedure ◽  
Camera System ◽  
Stereo Camera ◽  
Self Calibration ◽  
Planar Laser ◽  
Surface Measurements ◽  
Dimensional Domain

AbstractIn this work, we extend a planar laser-induced fluorescence method for free surface measurements to a three-dimensional domain using a stereo-camera system, a scanning light sheet, and a modified self-calibration procedure. The stereo-camera set-up enables a versatile measurement domain with self-calibration, improved accuracy, and redundancy (e.g., possibility to overcome occlusions). Fluid properties are not significantly altered by the fluorescent dye, which results in a non-intrusive measurement technique. The technique is validated by determining the free surface of a hydraulic flow over an obstacle and circular waves generated after droplet impact. Free surface waves can be accurately determined over a height of $$L=100$$L=100 mm in a large two-dimensional domain ($$y(x,z) = 120\times 62$$y(x,z)=120×62 mm$$^2$$2), with sufficient accuracy to determine small amplitude variations ($$\eta \approx 0.2$$η≈0.2 mm). The temporal resolution ($${\varDelta }t = 19$$Δt=19 ms) is only limited by the available scanning equipment ($$f = 1$$f=1 kHz rate). For other applications, this domain can be scaled as needed. Graphic abstract

Stereo camera system for three-dimensional reconstruction of a flyer plate in flight

2003 ◽  
Vol 74 (12) ◽  
pp. 5274-5281 ◽  
Author(s):  
Ted D. Rupp ◽  
Russell J. Gehr ◽  
Scott Bucholtz ◽  
David L. Robbins ◽  
David B. Stahl ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Flyer Plate ◽  
Three Dimensional Reconstruction ◽  
Camera System ◽  
Stereo Camera ◽  
Dimensional Reconstruction

Automated Composite Fabric Layup for Wind Turbine Blades

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Siqi Zhu ◽  
Corey J. Magnussen ◽  
Emily L. Judd ◽  
Matthew C. Frank ◽  
Frank E. Peters
Keyword(s):  
Wind Turbine ◽  
Plane Deformation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
3D Models ◽  
New Method ◽  
Two Dimensional ◽  
Wind Turbine Blades ◽  
Out Of Plane ◽  
Fiberglass Fabric

This work presents an automated fabric layup solution based on a new method to deform fiberglass fabric, referred to as shifting, for the layup of noncrimp fabric (NCF) plies. The shifting method is intended for fabric with tows only in 0 deg (warp) and 90 deg (weft) directions, where the fabric is sequentially constrained and then rotated through a deformation angle to approximate curvature. Shifting is conducted in a two-dimensional (2D) plane, making the process easy to control and automate, but can be applied for fabric placement in three-dimensional (3D) models, either directly or after a ply kitting process and then manually placed. Preliminary tests have been conducted to evaluate the physical plausibility of the shifting method. Layup tests show that shifting can deposit fabric accurately and repeatedly while avoiding out-of-plane deformation.

A Comparison Between the Accuracy of Two-Dimensional and Three-Dimensional Strain Measurements

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Niranjan Desai ◽  
Joel Poling ◽  
Gregor Fischer ◽  
Christos Georgakis
Keyword(s):  
Structural Damage ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Image Correlation ◽  
3D Measurement ◽  
Two Dimensional ◽  
Strain Measurements ◽  
Out Of Plane ◽  
2D System ◽  
Plane Displacement

This investigation determined the effect of specimen out-of-plane movement on the accuracy of strain measurement made applying two-dimensional (2D) and three-dimensional (3D) measurement approaches using the representative, state-of-the-art digital image correlation (DIC)-based tool ARAMIS. DIC techniques can be used in structural health monitoring (SHM) by measuring structural strains and correlating them to structural damage. This study was motivated by initially undetected damage at low strains in connections of a real-world bridge, whose detection would have prevented its propagation, resulting in lower repair costs. This study builds upon an initial investigation that concluded that out-of-plane specimen movement results in noise in DIC-based strain measurements. The effect of specimen out-of-plane displacement on the accuracy of strain measurements using the 2D and 3D measurement techniques was determined over a range of strain values and specimen out-of-plane displacements. Based upon the results of this study, the 2D system could measure strains as camera focus was being lost, and the effect of the loss of focus became apparent at 1.0 mm beam out-of-plane displacement while measuring strain of the order of magnitude of approximately 0.12%. The corresponding results for the 3D system demonstrate that the beam out-of-plane displacement begins to affect the accuracy of the strain measurements at approximately 0.025% strain for all magnitudes of out-of-plane displacement, and the 3D ARAMIS system can make accurate strain measurements at up to 2.5 mm amplitude at this strain. Finally, based upon the magnitudes of strain and out-of-plane displacement amplitudes that typically occur in real steel bridges, it is advisable to use the 3D system for SHM of stiff structures instead of the 2D system.

Modeling of Looping Behavior in a Flexible Instrument Using a Bélzier Curve

2021 ◽  
Author(s):  
Shobhit Singhal ◽  
Jitendra P. Khatait
Keyword(s):  
Strain Energy ◽  
Dimensional Space ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Flexible Instrument ◽  
Out Of Plane ◽  
Minimum Strain Energy ◽  
And Control ◽  
Three Dimensional Space

Abstract Flexible medical instruments undergo looping during insertion and navigation inside the human body. It makes the control of the distal end difficult and raises safety concerns. This paper proposes the minimum strain energy concept to get the deformed shape of a flexible instrument in three-dimensional space. A B\'{e}zier curve is used to define the trajectory of the deformed shape under different loading conditions and constraints. Looping behavior is studied for different end shortening conditions. The effect of end twist on looping behavior is studied. It is observed that end twist leads to early onset of out of plane deformation leading to looping. The strain energy plot gives an insight into the behavior of these instruments with respect to end shortening and twist. The strain energy plot shows the minimum value for $2\pi$ end twist. Therefore, the instrument tends to go for looping if the end twist is present. Force and torque characteristics are obtained which will lead to the design and control of these instruments. Force and torque plots show negative stiffness when the instrument is going for looping. The un-looping phenomenon is also discussed and a strategy is proposed to mitigate looping. The proposed modeling approach can be utilized to address the complex behavior of a flexible instrument in medical as well as in other industrial applications. The insight developed will help in designing and developing control for safe and reliable usage of flexible instruments in various domains.

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