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1 – 10 of over 5000Xindang He, Run Zhou, Zheyuan Liu, Suliang Yang, Ke Chen and Lei Li
The purpose of this paper is to provide a comprehensive review of a non-contact full-field optical measurement technique known as digital image correlation (DIC).
Abstract
Purpose
The purpose of this paper is to provide a comprehensive review of a non-contact full-field optical measurement technique known as digital image correlation (DIC).
Design/methodology/approach
The approach of this review paper is to introduce the research pertaining to DIC. It comprehensively covers crucial facets including its principles, historical development, core challenges, current research status and practical applications. Additionally, it delves into unresolved issues and outlines future research objectives.
Findings
The findings of this review encompass essential aspects of DIC, including core issues like the subpixel registration algorithm, camera calibration, measurement of surface deformation in 3D complex structures and applications in ultra-high-temperature settings. Additionally, the review presents the prevailing strategies for addressing these challenges, the most recent advancements in DIC applications across quasi-static, dynamic, ultra-high-temperature, large-scale and micro-scale engineering domains, along with key directions for future research endeavors.
Originality/value
This review holds a substantial value as it furnishes a comprehensive and in-depth introduction to DIC, while also spotlighting its prospective applications.
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Keywords
Linh Truong-Hong, Roderik Lindenbergh and Thu Anh Nguyen
Terrestrial laser scanning (TLS) point clouds have been widely used in deformation measurement for structures. However, reliability and accuracy of resulting deformation…
Abstract
Purpose
Terrestrial laser scanning (TLS) point clouds have been widely used in deformation measurement for structures. However, reliability and accuracy of resulting deformation estimation strongly depends on quality of each step of a workflow, which are not fully addressed. This study aims to give insight error of these steps, and results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. Thus, the main contributions of the paper are investigating point cloud registration error affecting resulting deformation estimation, identifying an appropriate segmentation method used to extract data points of a deformed surface, investigating a methodology to determine an un-deformed or a reference surface for estimating deformation, and proposing a methodology to minimize the impact of outlier, noisy data and/or mixed pixels on deformation estimation.
Design/methodology/approach
In practice, the quality of data point clouds and of surface extraction strongly impacts on resulting deformation estimation based on laser scanning point clouds, which can cause an incorrect decision on the state of the structure if uncertainty is available. In an effort to have more comprehensive insight into those impacts, this study addresses four issues: data errors due to data registration from multiple scanning stations (Issue 1), methods used to extract point clouds of structure surfaces (Issue 2), selection of the reference surface Sref to measure deformation (Issue 3), and available outlier and/or mixed pixels (Issue 4). This investigation demonstrates through estimating deformation of the bridge abutment, building and an oil storage tank.
Findings
The study shows that both random sample consensus (RANSAC) and region growing–based methods [a cell-based/voxel-based region growing (CRG/VRG)] can be extracted data points of surfaces, but RANSAC is only applicable for a primary primitive surface (e.g. a plane in this study) subjected to a small deformation (case study 2 and 3) and cannot eliminate mixed pixels. On another hand, CRG and VRG impose a suitable method applied for deformed, free-form surfaces. In addition, in practice, a reference surface of a structure is mostly not available. The use of a fitting plane based on a point cloud of a current surface would cause unrealistic and inaccurate deformation because outlier data points and data points of damaged areas affect an accuracy of the fitting plane. This study would recommend the use of a reference surface determined based on a design concept/specification. A smoothing method with a spatial interval can be effectively minimize, negative impact of outlier, noisy data and/or mixed pixels on deformation estimation.
Research limitations/implications
Due to difficulty in logistics, an independent measurement cannot be established to assess the deformation accuracy based on TLS data point cloud in the case studies of this research. However, common laser scanners using the time-of-flight or phase-shift principle provide point clouds with accuracy in the order of 1–6 mm, while the point clouds of triangulation scanners have sub-millimetre accuracy.
Practical implications
This study aims to give insight error of these steps, and the results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds.
Social implications
The results of this study would provide guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. A low-cost method can be applied for deformation analysis of the structure.
Originality/value
Although a large amount of the studies used laser scanning to measure structure deformation in the last two decades, the methods mainly applied were to measure change between two states (or epochs) of the structure surface and focused on quantifying deformation-based TLS point clouds. Those studies proved that a laser scanner could be an alternative unit to acquire spatial information for deformation monitoring. However, there are still challenges in establishing an appropriate procedure to collect a high quality of point clouds and develop methods to interpret the point clouds to obtain reliable and accurate deformation, when uncertainty, including data quality and reference information, is available. Therefore, this study demonstrates the impact of data quality in a term of point cloud registration error, selected methods for extracting point clouds of surfaces, identifying reference information, and available outlier, noisy data and/or mixed pixels on deformation estimation.
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Qiang Fang, Weidong Chen, Anan Zhao, Changxi Deng and Shaohua Fei
In aircraft wing–fuselage assembly, the distributed multi-point support layout of positioners causes fuselage to deform under gravity load, leading to assembly difficulty and…
Abstract
Purpose
In aircraft wing–fuselage assembly, the distributed multi-point support layout of positioners causes fuselage to deform under gravity load, leading to assembly difficulty and assembly stress. This paper aims to propose a hybrid force position control method to balance aerodynamic shape accuracy and deformation of assembly area, thereby correcting assembly deformation and reducing assembly stress.
Design/methodology/approach
Force and position control axes of positioners are selected based on screw theory and ellipsoid method. The position-control axes follow the posture trajectory to align the fuselage posture. To exert force on the fuselage and correct the deformations, the force-control axes follow the contact force derived by using orthogonal experiments and partial least squares regression (PLSR). Finite element simulation and one-dimension deformation correction experiment are conducted to verify the validity of this method.
Findings
Simulation results indicate that hybrid force position control method can correct assembly deformation and improve the wing–fuselage assembly quality significantly. Experiment on specimen verifies the effect of this method indirectly.
Originality/value
The proposed method gives a solution to solve the deformation problem during aircraft wing-fuselage assembly, thereby reducing assembly stress and improving assembly quality.
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Guangrun Sheng, Xixiang Liu, Zixuan Wang, Wenhao Pu, Xiaoqiang Wu and Xiaoshuang Ma
This paper aims to present a novel transfer alignment method based on combined double-time observations with velocity and attitude for ships’ poor maneuverability to address the…
Abstract
Purpose
This paper aims to present a novel transfer alignment method based on combined double-time observations with velocity and attitude for ships’ poor maneuverability to address the system errors introduced by flexural deformation and installing which are difficult to calibrate.
Design/methodology/approach
Based on velocity and attitude matching, redesigning and deducing Kalman filter model by combining double-time observation. By introducing the sampling of the previous update cycle of the strapdown inertial navigation system (SINS), current observation subtracts previous observation are used as measurements for transfer alignment filter, system error in measurement introduced by deformation and installing can be effectively removed.
Findings
The results of simulations and turntable tests show that when there is a system error, the proposed method can improve alignment accuracy, shorten the alignment process and not require any active maneuvers or additional sensor equipment.
Originality/value
Calibrating those deformations and installing errors during transfer alignment need special maneuvers along different axes, which is difficult to fulfill for ships’ poor maneuverability. Without additional sensor equipment and active maneuvers, the system errors in attitude measurement can be eliminated by the proposed algorithms, meanwhile improving the accuracy of the shipboard SINS transfer alignment.
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Pingan Zhu, Chao Zhang and Jun Zou
The purpose of the work is to provide a comprehensive review of the digital image correlation (DIC) technique for those who are interested in performing the DIC technique in the…
Abstract
Purpose
The purpose of the work is to provide a comprehensive review of the digital image correlation (DIC) technique for those who are interested in performing the DIC technique in the area of manufacturing.
Design/methodology/approach
No methodology was used because the paper is a review article.
Findings
no fundings.
Originality/value
Herein, the historical development, main strengths and measurement setup of DIC are introduced. Subsequently, the basic principles of the DIC technique are outlined in detail. The analysis of measurement accuracy associated with experimental factors and correlation algorithms is discussed and some useful recommendations for reducing measurement errors are also offered. Then, the utilization of DIC in different manufacturing fields (e.g. cutting, welding, forming and additive manufacturing) is summarized. Finally, the current challenges and prospects of DIC in intelligent manufacturing are discussed.
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Jonathan Ruiz-Jaramillo, Emilio Mascort-Albea and Antonio Jaramillo-Morilla
Growing awareness of the importance of preserving the built environment has created an increasing demand for experts capable of performing building inspections to ensure a high…
Abstract
Purpose
Growing awareness of the importance of preserving the built environment has created an increasing demand for experts capable of performing building inspections to ensure a high level of preservation. Technical surveys include a set of procedures and tests that have become essential tools providing the necessary knowledge required for maintenance, preservation and improvement of buildings. The paper aims to discuss these issues.
Design/methodology/approach
Within this set of inspection techniques, this paper presents a method developed to produce vertical deformation plans from the levelling data obtained from different floors of a building. It also explains how to perform accurate levelling and an outcome analysis to provide displacement maps. Thus, based upon obtained measurements, it is possible to achieve 2D contour maps and three-dimensional (3D) surface mapping by means of specialized software that is typically used for cartographic and territorial analysis.
Findings
The developed methodology provides easier analysis of the deformation of buildings and structures. Consequently, the method produces relatively accurate outcomes that are sufficient to make a proper assessment that facilitates the diagnostic and decision-making process. The case studies analysed show the applicability and usefulness of the procedure.
Originality/value
This sustainable and non-destructive system is an essential instrument for providing valuable and useful information to the specialist. The 2D/3D graphical data displays enable easier analysis of survey results, also aiding comprehension of these results in the context of liability claims.
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Technical means now exist to monitor, predict a danger and issue early warnings when something devastating is estimated to happen in the human environment. In order to adapt such…
Abstract
Technical means now exist to monitor, predict a danger and issue early warnings when something devastating is estimated to happen in the human environment. In order to adapt such means for the benefit of humanity, existing monitoring methods, basic system design principles and natural short and long environmental transformations were investigated. Finally an integrated automatic system for deformation monitoring and surveying of the Chernobyl disaster area, was proposed. The conclusion was that airborne remote sensing including GPS and photogrammetry can be considered the optimum solution.
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This paper aims to present an adaptation of digital image correlation (DIC) to the electronics industry for reliability assessment of electronic packages. Two case studies are…
Abstract
Purpose
This paper aims to present an adaptation of digital image correlation (DIC) to the electronics industry for reliability assessment of electronic packages. Two case studies are presented: one for warpage measurement of a micro-electro-mechanical system (MEMS) package under different temperature conditions and the other for the measurement of transient displacements on the surface of a printed circuit board (PCB) assembly under free-fall drop conditions, which is for explaining the typical camera setup requirement and comparing among different boundary conditions by fastening methods of PCB.
Design/methodology/approach
DIC warpage measurements on a small device, such as a MEMS package, require a special speckle pattern. A new method for the creation of speckle patterns was developed using carbon coating and aluminum evaporative deposition. To measure the transient response on the surface of a PCB during a free-fall impact event, three-dimensional (3D) DIC was integrated with synchronized stereo-high speed cameras. This approach enables the measurement of full-field displacement on the PCB surface during a free-fall impact event, contrary to the localized information that is obtained by the conventional strain gage and accelerometer method.
Findings
The authors suggest the proposed patterning method to the small-sized microelectronics packages for DIC measurements. More generally, the idea is to have a thin layer of the dark or bright color of the background and then apply the white or black colored pattern, respectively, so that the surface has high contrast. Also, to achieve a proper size of speckles, this paper does not want to expose the measuring objects to high temperatures or pressures during the sample preparation stage. Of course, it seems a complicated process to use aluminum evaporator, carbon coater and electroformed mesh. However, the authors intend to share one of the solutions to achieve a proper pattern on such small-sized electronic packages.
Originality/value
3D DIC technique can be successfully implemented for the measurement of micro-scale deformations in small packages (such as MEMS) and for the analysis of dynamic deformation of complex PCB.
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Guangbin Dou, David C. Whalley, Changqing Liu and Y.C. Chan
Non‐planarity of assemblies and co‐planarity variation effects on anisotropic conductive adhesive (ACA) assemblies have been a concern for ACA users since the materials are first…
Abstract
Purpose
Non‐planarity of assemblies and co‐planarity variation effects on anisotropic conductive adhesive (ACA) assemblies have been a concern for ACA users since the materials are first devised. The primary objective of this paper is to introduce a new experimental method for studying co‐planarity variation effects on ACA assemblies.
Design/methodology/approach
The approach simulates non‐planarity through deliberate chip rotation during the ACA bonding process, thereby locking different levels of co‐planarity variation into ACA test assemblies. Scanning electron microscope (SEM) analysis and electrical joint resistance measurement using the four wire resistance (FWR) method are used to mechanically and electrically examine the connection quality of the ACA assemblies bonded with non‐planar joints, for which the chip and substrate patterns are specially designed to allow joint resistance measurement using the FWR method.
Findings
Typical experiments and their results are presented and analysed. The bond thickness differences between the SEM measurements and calculations indicate that the real rotations are smaller than those predicted by the calculations. The typical experimental results show that the joint resistance reduces as the deformation increases until reaching a relatively stable value after a certain deformation degree.
Research limitations/implications
The average joint resistances in the rotated samples are all bigger than those measured in the un‐rotated samples. This raises the question as to whether the joint resistances of ACA assemblies are more significantly affected by other affects of non‐planarity than just by its effect on bond thickness. However, before this can be confirmed, more research must be done to check if this behaviour happens for different bonding forces.
Originality/value
This paper reports a novel and simple experiment that can be used to examine the effects of co‐planarity variation on the electrical performance of ACA assemblies, by creating different bond thicknesses that are normally difficult to achieve by changing the bonding pressure, since ACA bond thicknesses are not linearly related to the bonding force. The merit of the technique is that there is no need to manufacture chip bumps and substrate pads with different geometries, or to control the bond pressure, to achieve bond thickness variation in ACA assemblies.
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Yosuke Horiba, Ayumu Tokutake and S. Inui
Mobility is one of the important elements in clothing design. The purpose of this paper is to examine the predictability of clothing mobility via musculoskeletal simulation.
Abstract
Purpose
Mobility is one of the important elements in clothing design. The purpose of this paper is to examine the predictability of clothing mobility via musculoskeletal simulation.
Design/methodology/approach
In order to carry out the musculoskeletal simulation considering the influence of clothing, simulation of the dressed state was attempted. This paper simulated the dressed state and measured the motion-related deformation of the clothing to estimate the force applied to the human body based on the material property of the clothing samples. The dressed state was simulated using an external force in the musculoskeletal model.
Findings
When the elbow flexion torque with an elbow supporter was calculated using the above-mentioned method of musculoskeletal simulation, it was confirmed that the lower the stretchability of the sample, the higher the elbow flexion torque. In addition, the sensory evaluation performed under the same condition as that in the simulation showed that the lower the joint torque during the motion, the higher the subjective mobility, and that the higher the joint torque, the lower the subjective mobility. Thus, it is suggested that musculoskeletal simulation of the dressed state can predict the clothing mobility.
Research limitations/implications
However, the method proposed in this paper requires the measurement of the deformation of the clothing to estimate the force applied to the human body. Thus, it is difficult to apply this in the measurement of general clothing that allows enough space between it and the human body, requiring further improvement of the dressed state simulation method.
Originality/value
Because it is difficult to estimate the force applied by the clothing to the human body, only a few studies have performed analysis on the effect of clothing by using musculoskeletal simulation. Conversely, although the force applied by the clothing to the human body needs to be estimated in advance by the measurement of the deformation, the utility of the simulation in clothing design seems to be high because the simulation can estimate clothing mobility and the effects of clothing on muscle activity.
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