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

2021 ◽  
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 Characterization and ballistic performance of thin pre-damaged resin-starved aramid-fiber composite panels

2021 ◽  
pp. 004051752110134
Author(s):  
Cerise A Edwards ◽  
Stephen L Ogin ◽  
David A Jesson ◽  
Matthew Oldfield ◽  
Rebecca L Livesey ◽  
...  
Keyword(s):  
Fiber Composite ◽  
Plane Deformation ◽  
Ballistic Impact ◽  
Image Correlation ◽  
Composite Panel ◽  
Composite Panels ◽  
Micro Computed Tomography ◽  
Ballistic Performance ◽  
Low Level ◽  
Out Of Plane

Military personnel use protective armor systems that are frequently exposed to low-level damage, such as non-ballistic impact, wear-and-tear from everyday use, and damage during storage of equipment. The extent to which such low-level pre-damage could affect the performance of an armor system is unknown. In this work, low-level pre-damage has been introduced into a Kevlar/phenolic resin-starved composite panel using tensile loading. The tensile stress–strain behavior of this eight-layer material has been investigated and has been found to have two distinct regions; these have been understood in terms of the microstructure and damage within the composite panels investigated using micro-computed tomography and digital image correlation. Ballistic testing carried out on pristine (control) and pre-damaged panels did not indicate any difference in the V50 ballistic performance. However, an indication of a difference in response to ballistic impact was observed; the area of maximal local out-of-plane deformation for the pre-damaged panels was found to be twice that of the control panels, and the global out-of-plane deformation across the panel was also larger.

Prediction and Optimization of Deformations in Coupling Mechanism Based Laser Forming of Sheet Metals

2019 ◽  
Vol 969 ◽  
pp. 552-557
Author(s):  
Kuntal Maji
Keyword(s):  
Process Parameters ◽  
Metal Forming ◽  
Three Dimensional ◽  
Laser Forming ◽  
Coupling Mechanism ◽  
Sheet Metals ◽  
Forming Process ◽  
Out Of Plane ◽  
Metal Forming Process ◽  
Plane Deformations

Fabricating three dimensional shaped surfaces from flat sheet metals by laser forming, both out-of-plane and in-plane deformations are required. This article presents the modeling of coupling mechanism activated laser forming of sheet metals based on experimental data for prediction and optimization of bending and thickening deformations. Experiments were performed based on a central composite design of experiments on coupling mechanism based laser metal forming process considering the input process parameters like laser power, scan speed and spot diameter, bending and thickening were taken as the outputs. Neural network and neuro-fuzzy system-based models were developed to carry out both forward and inverse modeling of the laser metal forming process under the coupling mechanism. Multi-objective optimization based on the non-dominated sorting genetic algorithm was used to obtain multiple optimal solutions to achieve different amounts of out-of-plane and in-plane deformations. The proposed method could guide for a suitable selection of the process parameters to produce three-dimensional shapes utilizing coupling mechanism-based laser forming using multiple laser line heating.

Study on Welding Deformations of Shipboard of Container Vessel

2011 ◽  
Vol 488-489 ◽  
pp. 218-221
Author(s):  
Hong Li ◽  
Da Lu Qiu ◽  
Guang Lei Li ◽  
Hui Long Ren
Keyword(s):  
Heat Flux ◽  
Heat Source ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Plastic Strains ◽  
Out Of Plane ◽  
Inherent Strain ◽  
Nonlinear Behaviors ◽  
Plane Deformations

Residual plastic strains of the shipboard are the product of nonlinear behaviors during welding. Deformations of a welded shipboard injure the beauty of appearance of the ship, cause errors during the assembly of the shipboard and reduce the strength of the ship. Residual welding deformations of shipboard of a container vessel are studied in this paper. Nonlinear three dimensional transient temperature fields are analyzed by FEM first. The heat source is modeled as a moving heat flux following a Gaussian distribution. Then, applying the equivalent loads induced by the inherent strain on the shipboard, the final in-plane shrinkage and out-of-plane deformations are calculated. Being compared with the experimental results of deformations, the simulated results show mostly conformity.

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 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.

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