scholarly journals Defect Characteristics and Online Detection Techniques During Manufacturing of FRPs Using Automated Fiber Placement: A Review

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1337 ◽  
Author(s):  
Shouzheng Sun ◽  
Zhenyu Han ◽  
Hongya Fu ◽  
Hongyu Jin ◽  
Jaspreet Singh Dhupia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Variable Stiffness ◽  
Future Research ◽  
Online Detection ◽  
Manufacturing Defects ◽  
Manufacturing Method ◽  
Detection Techniques ◽  
Fiber Placement ◽  
Automated Fiber Placement

Automated fiber placement (AFP) is an advanced manufacturing method for composites, which is especially suitable for large-scale composite components. However, some manufacturing defects inevitably appear in the AFP process, which can affect the mechanical properties of composites. This work aims to investigate the recent works on manufacturing defects and their online detection techniques during the AFP process. The main content focuses on the position defect in conventional and variable stiffness laminates, the relationship between the defects and the mechanical properties, defect control methods, the modeling method for a void defect, and online detection techniques. Following that, the contributions and limitations of the current studies are discussed. Finally, the prospects of future research concerning theoretical and practical engineering applications are pointed out.

scholarly journals Multiscale Collaborative Optimization of Processing Parameters for Carbon Fiber/Epoxy Laminates Fabricated by High-Speed Automated Fiber Placement

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Zhenyu Han ◽  
Shouzheng Sun ◽  
Zhongxi Shao ◽  
Hongya Fu
Keyword(s):  
Mechanical Properties ◽  
Strain Energy ◽  
High Speed ◽  
Processing Parameters ◽  
Collaborative Optimization ◽  
Manufacturing Defects ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Processing Optimization ◽  
Carbon Fiber Epoxy

Processing optimization is an important means to inhibit manufacturing defects efficiently. However, processing optimization used by experiments or macroscopic theories in high-speed automated fiber placement (AFP) suffers from some restrictions, because multiscale effect of laying tows and their manufacturing defects could not be considered. In this paper, processing parameters, including compaction force, laying speed, and preheating temperature, are optimized by multiscale collaborative optimization in AFP process. Firstly, rational model between cracks and strain energy is revealed in order that the formative possibility of cracks could be assessed by using strain energy or its density. Following that, an antisequential hierarchical multiscale collaborative optimization method is presented to resolve multiscale effect of structure and mechanical properties for laying tows or cracks in high-speed automated fiber placement process. According to the above method and taking carbon fiber/epoxy tow as an example, multiscale mechanical properties of laying tow under different processing parameters are investigated through simulation, which includes recoverable strain energy (ALLSE) of macroscale, strain energy density (SED) of mesoscale, and interface absorbability and matrix fluidity of microscale. Finally, response surface method (RSM) is used to optimize the processing parameters. Two groups of processing parameters, which have higher desirability, are obtained to achieve the purpose of multiscale collaborative optimization.

Design and analysis of the mandrel structure for a composite S-shaped inlet

2021 ◽  
pp. 095441002110087
Author(s):  
Hao Li ◽  
Junxia Jiang ◽  
Yinglin Ke
Keyword(s):  
Large Scale ◽  
Optimization Problem ◽  
Structure Design ◽  
Penalty Function Method ◽  
Forming Process ◽  
Manufacturing Method ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Axis Position

Automated fiber placement (AFP) combining with the autoclave curing process is the main manufacturing method for large-scale rotary composite parts. During the forming process, the mandrel plays an important role that affects the forming quality of the part directly. In this study, design and analysis of the mandrel structure for a composite S-shaped inlet are carried out. The preforming process of the rotary composite part using the AFP technique is introduced first. Then, design principles of the shaft are presented and applied to the shaft design for the mandrel of the S-shaped inlet, which then is transformed into an optimization problem. The internal penalty function method is adopted to solve this optimization problem in order to obtain the optimal axis position and axle diameter. Moreover, detailed structure design of the mandrel is proposed which takes the demolding into consideration, and the wall thickness is designed considering the total weight and the stiffness. The static analysis and modal analysis are also carried out by the finite element method to verify the feasibility of the proposed mandrel structure.

scholarly journals Optimization of variable stiffness composites with embedded defects induced by Automated Fiber Placement

2014 ◽  
Vol 107 ◽  
pp. 160-166 ◽  
Author(s):  
Mahdi Arian Nik ◽  
Kazem Fayazbakhsh ◽  
Damiano Pasini ◽  
Larry Lessard
Keyword(s):  
Variable Stiffness ◽  
Fiber Placement ◽  
Automated Fiber Placement

scholarly journals Salient Object Detection Techniques in Computer Vision—A Survey

Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1174
Author(s):  
Ashish Kumar Gupta ◽  
Ayan Seal ◽  
Mukesh Prasad ◽  
Pritee Khanna
Keyword(s):  
Computer Vision ◽  
Deep Learning ◽  
Object Detection ◽  
Large Scale ◽  
Research Work ◽  
Salient Object Detection ◽  
Future Research ◽  
Automatic Identification ◽  
Salient Object ◽  
Detection Techniques

Detection and localization of regions of images that attract immediate human visual attention is currently an intensive area of research in computer vision. The capability of automatic identification and segmentation of such salient image regions has immediate consequences for applications in the field of computer vision, computer graphics, and multimedia. A large number of salient object detection (SOD) methods have been devised to effectively mimic the capability of the human visual system to detect the salient regions in images. These methods can be broadly categorized into two categories based on their feature engineering mechanism: conventional or deep learning-based. In this survey, most of the influential advances in image-based SOD from both conventional as well as deep learning-based categories have been reviewed in detail. Relevant saliency modeling trends with key issues, core techniques, and the scope for future research work have been discussed in the context of difficulties often faced in salient object detection. Results are presented for various challenging cases for some large-scale public datasets. Different metrics considered for assessment of the performance of state-of-the-art salient object detection models are also covered. Some future directions for SOD are presented towards end.

Size-dependent behavior of laminates with curvilinear fibers made by automated fiber placement

2015 ◽  
Vol 22 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Mahdi Arian Nik ◽  
Larry Lessard ◽  
Damiano Pasini
Keyword(s):  
Variable Stiffness ◽  
Buckling Load ◽  
Fiber Placement ◽  
Plate Size ◽  
Load Increase ◽  
Automated Fiber Placement ◽  
Fiber Path ◽  
Turning Radius ◽  
Curvilinear Fibers ◽  
Minimum Turning Radius

AbstractVariable stiffness laminates can be manufactured using curvilinear fiber paths. A curvilinear fiber path is generally defined based on the plate size and has a curvature that is dependent on the plate size. In practice, however, the fiber path must satisfy manufacturing constraints, such as the minimum turning radius imposed by the automated fiber placement machine, thereby limiting the possible amount of fiber steering. In this work, we studied the effect of the plate size on the structural properties of a plate manufactured with curvilinear fibers. We considered four plate sizes, which were designed by a constant curvature fiber path. We optimized the plates for both maximum buckling load and in-plane stiffness. The results showed that the in-plane stiffness of the plate was not controlled by the plate size, whereas the buckling load was highly affected by the curvature of the fiber path. Hence, the potential of a buckling load increase reduced for plate sizes smaller than the minimum turning radius. In addition, for a given maximum curvature of the fiber path, the influence of a complex layup on the buckling load was marginal.

scholarly journals Manufacturing-Induced Imperfections in Composite Parts Manufactured via Automated Fiber Placement

2019 ◽  
Vol 3 (2) ◽  
pp. 56 ◽  
Author(s):  
Falk Heinecke ◽  
Christian Willberg
Keyword(s):  
Composite Structures ◽  
Review Paper ◽  
State Of The Art ◽  
Fiber Composite ◽  
Research Gaps ◽  
Manufacturing Defects ◽  
Cycle Times ◽  
Fiber Placement ◽  
Simulation Based ◽  
Automated Fiber Placement

The automated fiber placement process (AFP) enables the manufacturing of large and geometrical complex fiber composite structures with high quality at low cycle times. Although the AFP process is highly accurate and reproducible, manufacturing induced imperfections in the produced composite structure occur. This review summarizes and classifies typical AFP-related manufacturing defects. Several methodologies for evaluating the effects of such manufacturing defects from the literature are reviewed. This review paper presents recent scientific contributions and discusses proposed experimental and simulation-based methodologies. Among the identified ten defect classes, gaps and overlaps are predominant. This paper focuses then on methods for modelling and assessing gaps and overlaps. The state of the art in modelling gaps and overlaps and assessing their influence on mechanical properties is presented. Finally, research gaps and remaining issues are identified.

Characterization of process-induced defects in automated fiber placement manufacturing of composites using fiber Bragg grating sensors

2017 ◽  
Vol 17 (1) ◽  
pp. 108-117 ◽  
Author(s):  
Ebrahim Oromiehie ◽  
B Gangadhara Prusty ◽  
Paul Compston ◽  
Ginu Rajan
Keyword(s):  
Fiber Bragg Grating ◽  
Structural Integrity ◽  
Bragg Grating ◽  
Inspection Method ◽  
Manufacturing Defects ◽  
Fiber Placement ◽  
Fiber Bragg Grating Sensors ◽  
Placement Method ◽  
Automated Fiber Placement ◽  
On Line

With the increasing use of automated fiber placement method for manufacturing highly precise bespoke composite components in the aerospace industry, the level of manufacturing defects within the laminate structure needs to be monitored and minimized for structural integrity. One of the main common defects in automated fiber placement process is misalignment between the tape paths in successive courses which leads to non-integrity of laminate and consequently significant reduction in mechanical strength of the laminate. Therefore, it is necessary to find an appropriate inspection method to monitor and identify these processing defects at the earlier stages of manufacturing. Since optical fiber Bragg grating sensors are being increasingly utilized for structural health monitoring in composite materials and as they were successfully implemented by Oromiehie et al. in their earlier work for on-line lay-up process monitoring, the same methodology is once again tried for identifying the misalignment defects in automated fiber placement process. The experiments are carried out on glass-fiber/nylon laminate with embedded fiber Bragg gratings for the automated tape placement method. The defects due to misalignment are identified by the fiber Bragg grating sensors through their reflected wavelength changes during the automated manufacturing process. The analysis of results indicates that the fiber Bragg grating sensors can be reliably implemented for on-line defect monitoring during the automated fiber placement process to ensure the quality of final product and maintain the expected design life.

scholarly journals Influence of Embedded Gap and Overlap Fiber Placement Defects on Interlaminar Properties of High Performance Composites

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5332
Author(s):  
Denis Cartié ◽  
Marine Lan ◽  
Peter Davies ◽  
Christophe Baley
Keyword(s):  
High Performance ◽  
Crack Arrest ◽  
Shear Loading ◽  
Plane Shear ◽  
Manufacturing Defects ◽  
Fiber Placement ◽  
Out Of Plane ◽  
Beam Shear ◽  
Automated Fiber Placement ◽  
Interlaminar Shear

Automated fiber placement (AFP), once limited to aerospace, is gaining acceptance and offers great potential for marine structures. This paper describes the influence of manufacturing defects, gaps, and overlaps, on the out-of-plane properties of carbon/epoxy composites manufactured by AFP. Apparent interlaminar shear strength measured by short beam shear tests was not affected by the presence of defects. However, the defects do affect delamination propagation. Under Mode I (tension) loading a small crack arrest effect is noted, resulting in higher apparent fracture energies, particularly for specimens manufactured using a caul plate. Under Mode II (in-plane shear) loading there is a more significant effect with increased fracture resistance, as stable propagation for specimens with small gaps changes to arrest with unstable propagation for larger gaps.

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