scholarly journals Surface parameters measurement for braided composite preform based on gray projection

2019 ◽  
Vol 14 ◽  
pp. 155892501988762
Author(s):  
Lei Pei ◽  
Zhitao Xiao ◽  
Lei Geng ◽  
Jun Wu ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Automatic Measurement ◽  
Block Matching ◽  
Original Image ◽  
Phase Congruency ◽  
Average Surface ◽  
Braided Composite ◽  
Edge Direction ◽  
Pitch Length ◽  
Braiding Angle

In this article, a method based on gray projection is proposed for automatic measurement of surface braiding angle and pitch length of braided composite preforms. The surface braiding angles are measured by rotated gray projection. First, the original image is preprocessed using Lab transform and block-matching and three-dimensional filter. Then, edge map of gray scale is acquired based on phase congruency and non-maximum suppression. Third, edge direction angles are computed by image rotation and gray projection. Finally, the average surface braiding angles are measured from the edge direction angles. The pitch lengths are measured by cropped gray projection. First, the original image is filtered by an artistic edge and corner enhancing filter. Second, block images are cropped based on gray projection. Finally, pitch lengths are measured by block images gray projection. Experimental results show that the proposed method can achieve the automatic measurement of average surface braiding angle and average pitch length of two-dimensional braided composite preform with high accuracy.

Measurement of surface parameters of three-dimensional braided composite preform based on curvature scale space corner detector

2017 ◽  
Vol 88 (23) ◽  
pp. 2641-2653 ◽  
Author(s):  
Zhitao Xiao ◽  
Lei Pei ◽  
Fang Zhang ◽  
Lei Geng ◽  
Jun Wu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Ccd Camera ◽  
Scale Space ◽  
Adaptive Threshold ◽  
Block Matching ◽  
Original Image ◽  
Braided Composite ◽  
Curvature Scale Space ◽  
Pitch Length ◽  
Braiding Angle

Surface braiding angle and pitch length are two important parameters for characterizing and evaluating the performance of three-dimensional braided composite preforms. In this paper a new method based on an improved curvature scale space corner detector with adaptive threshold is proposed for measuring these parameters, with applications to three-dimensional, four-directional carbon-fiber braided composite preforms. First, the original image is acquired using a system employing ‘dome light source + CCD camera + circular polarizing filter’. Second, the original image is processed using Lab transform and BM3D (block-matching and 3D filter). Third, the corners are detected using an improved curvature scale space corner detector with adaptive threshold. Finally, the pitch lengths and surface braiding angles are measured from the detected corners. Experimental results show that the proposed method can achieve automatic measurement of the pitch length and surface braiding angle with smaller average errors relative to manual measurements compared with alternative schemes.

scholarly journals Parameter Measurement of Biaxial Braided Composite Preform Based on Phase Congruency

2019 ◽  
Vol 19 (1) ◽  
pp. 8-16
Author(s):  
Zhitao Xiao ◽  
Lei Pei ◽  
Fang Zhang ◽  
Ying Sun ◽  
Lei Geng ◽  
...  
Keyword(s):  
Automatic Measurement ◽  
Detection Algorithm ◽  
High Accuracy ◽  
Block Matching ◽  
Experimental Results ◽  
Corner Detection ◽  
New Method ◽  
Two Dimensional ◽  
Phase Congruency ◽  
Braided Composite

Abstract In this paper, a new method based on phase congruency is proposed to measure pitch lengths and surface braiding angles of two-dimensional biaxial braided composite preforms. Lab space transform and BM3D (block-matching and 3D filter) are used first to preprocess the original acquired images. A corner detection algorithm based on phase congruency is then proposed to detect the corners of the preprocessed images. Pitch lengths and surface braiding angles are finally measured based on the detected corner maps. Experimental results show that our method achieves the automatic measurement of pitch lengths and the surface braiding angles of biaxial braided composite preforms with high accuracy.

Prediction of Elastic Properties of 3D4d Braided Composite Based on Hybrid Model

2017 ◽  
Vol 754 ◽  
pp. 222-225
Author(s):  
Di Zhang ◽  
Xi Tao Zheng ◽  
Tian Chi Wu
Keyword(s):  
Elastic Properties ◽  
Hybrid Model ◽  
Structural Model ◽  
Three Dimensional ◽  
Analytical Models ◽  
Braided Composites ◽  
Braided Composite ◽  
Relative Errors ◽  
Braiding Angle ◽  
Stress Models

This paper presents a meso-scale hybrid model which is used to predict the elastic properties of three-dimensional (3D) four-directional (4d) braided composites. At first, based on meso-structural model of 3D4d braided composite and the assumptions of iso-strain and iso-stress, two analytical models are established. Secondly, a hybrid model used to predict the elastic modulus of the 3D4d braided composite is established which introduces a new factor called hybrid-coefficient Ψ, which incorporates the iso-strain and iso-stress models at the same time, the value of Ψ is dependant on the braiding angle. Comparison between theoretical and experimental results shows that the hybrid model is more accurate than the iso-strain and iso-stress models, and can be used to predict the elastic properties of 3D4d braided composites, with the relative errors around 10%.

scholarly journals Braided composite stent for peripheral vascular applications

2020 ◽  
Vol 9 (1) ◽  
pp. 1137-1146
Author(s):  
Qingli Zheng ◽  
Pengfei Dong ◽  
Zhiqiang Li ◽  
Ying Lv ◽  
Meiwen An ◽  
...  
Keyword(s):  
Computational Models ◽  
Surface Coverage ◽  
Mechanical Performance ◽  
Wire Diameter ◽  
Orthogonal Experimental Design ◽  
Braided Composite ◽  
Nitinol Wire ◽  
Radial Strength ◽  
Braiding Angle ◽  
The Impact

AbstractBraided composite stent (BCS), woven with nitinol wires and polyethylene terephthalate (PET) strips, provides a hybrid design of stent. The mechanical performance of this novel stent has not been fully investigated yet. In this work, the influence of five main design factors (number of nitinol wires, braiding angle, diameter of nitinol wire, thickness and stiffness of the PET strip) on the surface coverage, radial strength, and flexibility of the BCS were systematically studied using computational models. The orthogonal experimental design was adopted to quantitatively analyze the sensitivity of multiple factors using the minimal number of study cases. Results have shown that the nitinol wire diameter and the braiding angle are two most important factors determining the mechanical performance of the BCS. A larger nitinol wire diameter led to a larger radial strength and less flexibility of the BCS. A larger braiding angle could provide a larger radial strength and better flexibility. In addition, the impact of the braiding angle decreased when the stent underwent a large deformation. At the same time, the impact of the PET strips increased due to the interaction with nitinol wires. Moreover, the number of PET strips played an important role in the surface coverage. This study could help understand the mechanical performance of BCS stent and provides guidance on the optimal design of the stent targeting less complications.

EFFECT OF ABRASIVE TYPE ON THE SURFACE ROUGHNESS AND MRR IN MAF OF AISI 304 STEEL

2021 ◽  
Author(s):  
MAHMUT ÇELIK ◽  
HAKAN GÜRÜN ◽  
ULAŞ ÇAYDAŞ
Keyword(s):  
Surface Roughness ◽  
Removal Rate ◽  
Three Dimensional ◽  
Steel Plates ◽  
304 Stainless Steel ◽  
Average Surface Roughness ◽  
Machining Time ◽  
Aisi 304 ◽  
Average Surface ◽  
Different Levels

In this study, the effects of experimental parameters on average surface roughness and material removal rate (MRR) were experimentally investigated by machining of AISI 304 stainless steel plates by magnetic abrasive finishing (MAF) method. In the study in which three different abrasive types were used (Al2O3, B4C, SiC), the abrasive grain size was changed in two different levels (50 and 80[Formula: see text][Formula: see text]m), while the machining time was changed in three different levels (30, 45, 60[Formula: see text]min). Surface roughness values of finished surfaces were measured by using three-dimensional (3D) optical surface profilometer and surface topographies were created. MRRs were measured with the help of precision scales. The abrasive particles’ condition before and after the MAF process was examined and compared using a scanning electron microscope. As a result of the study, the surface roughness values of plates were reduced from 0.106[Formula: see text][Formula: see text]m to 0.028[Formula: see text][Formula: see text]m. It was determined that the best parameters in terms of average surface roughness were 60[Formula: see text]min machining time with 50[Formula: see text][Formula: see text]m B4C abrasives, while the best result in terms of MRR was taken in 30[Formula: see text]min with 50[Formula: see text][Formula: see text]m SiC abrasives.

scholarly journals Three-Dimensional Mirror Surface Measurement Based on Local Blur Analysis of Phase Measuring Deflectometry System

2020 ◽  
Vol 37 (5) ◽  
pp. 763-771
Author(s):  
Hongyu Sun ◽  
Le Wang ◽  
Zhan Song ◽  
Geng Chen
Keyword(s):  
Measurement Techniques ◽  
Three Dimensional ◽  
Block Matching ◽  
Surface Measurement ◽  
Mirror Surface ◽  
Reconstruction Accuracy ◽  
Surface Reflection ◽  
Block Matching Algorithm ◽  
Reflective Mirror ◽  
Spatially Varying

Despite the marked progress in recent years, structured light-based three-dimensional (3D) measurement techniques still have difficulty in capturing mirror surface reflection. The accuracy of 3D reconstruction for mirror objects should be further improved to adapt to the high reflectivity and curvature of such objects. To improve the stripe definition and reconstruction accuracy of highly reflective mirror objects, this paper analyzes the local blur of defocus stripes in phase measuring deflectometry (PMD) system, and presents a method to analyze the spatially varying defocusing and de-blurring, with the aid of a 3D block matching algorithm, thereby focusing on defocus stripes. Experimental results show that the proposed method can achieve micron-level reconstruction accuracy of standard flat mirrors, and detect the defects on highly reflective mirror objects at a high precision.

Failure analysis of three-dimensional braided composite tubes under torsional load: Experimental study

2017 ◽  
Vol 36 (12) ◽  
pp. 878-888 ◽  
Author(s):  
Xiaopei Wang ◽  
Deng’an Cai ◽  
Chao Li ◽  
Fangzhou Lu ◽  
Yu Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Failure Modes ◽  
Shear Failure ◽  
Three Dimensional ◽  
Damage Mechanism ◽  
Test Device ◽  
Composite Tubes ◽  
Torsional Strength ◽  
Braided Composite ◽  
Torsional Load

An experimental study on the effects of braided processes on the torsional strength, torsional modulus and failure modes of the three-dimensional braided composite tubes are presented. Based on the movement of carries, the yarn traces of three-dimensional braided composite tubes are analyzed systematically. Four different three-dimensional braided composite tubes are formed by resin transfer molding, and a number of torsional tests are performed respectively using a special test device. It is found that the torsional strength of three-dimensional five-directional braided composite tubes is higher than others, while the torsional modulus of three-dimensional multi-layer wrapping braided composite tubes is the highest. Furthermore, the damage behaviors of 3D braided composite tubes are significantly influenced by braiding process. One focus is to evaluate the damage mechanism of three-dimensional braided composite tubes by cutting the specimens and using scanning electron microscopy. Under torsional load, three-dimensional five-directional braided composite tubes and three-dimensional surface-core five-directional braided composite tubes are fractured in compression and shear failure, while three-dimensional multi-layer wrapping braided composite tubes and three-dimensional seven-directional braided composite tubes are split open in tensile and shear failure.

Research on Fabricating Technology of Three Dimensional Integrated Braided Composite I Beam

2010 ◽  
Vol 136 ◽  
pp. 59-63 ◽  
Author(s):  
X.Y. Pei ◽  
Jia Lu Li
Keyword(s):  
Cross Section ◽  
High Performance ◽  
Research Result ◽  
Three Dimensional ◽  
Void Content ◽  
Braided Composites ◽  
Braided Composite ◽  
Transfer Molding ◽  
3D Braided Composites

In this paper the fabricating technology of three dimensional (3D) integrated braided composite I beam is researched, including: braiding technology of 3D braided I beam preform, the orientation of fiber-tow in the I beam preform, the optimizing of process parameters of resin transfer molding (RTM) for 3D braided composite I beam, and the design of mould for consolidation of composite I beam. The quality of 3D braided composites is good analyzed by ultrasonic A-scan, void content calculation and microscope observation. The research result will provide a good way for designing and fabricating high performance 3D integrated braided composite components with irregular cross section.

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