On the Understanding of Tensile Elastic and Strength Properties of Integrally Woven 3D Carbon Composites

2002 ◽  
Author(s):  
Larry C. Dickinson ◽  
Alexander E. Bogdanovich
Keyword(s):  
Three Dimensional ◽  
Theoretical Work ◽  
Strength Properties ◽  
Textile Composites ◽  
Woven Composites ◽  
Carbon Composites ◽  
Significant Difference ◽  
3D Woven Composites ◽  
The Difference ◽  
3D Orthogonal Woven

There is significant literature reporting research on three-dimensional (3D) textile composites. Previous experimental and theoretical work has shown that small details of design and structure of 3D woven composites have a significant effect on strength and failure mechanisms. This work presents the results of an experimental study examining the effect of thickness (number of warp layers) on tensile behavior of 3D orthogonal woven carbon/epoxy composites. Three different preform designs resulting in three different thicknesses were examined. There is a significant difference between warp (x) and fill (y) tensile properties strength, and the difference is a function of thickness.

Comparison of Two Approaches to Model Cure-Induced Microcracking in Three-Dimensional Woven Composites

2012 ◽  
Author(s):  
Igor Tsukrov ◽  
Michael Giovinazzo ◽  
Kateryna Vyshenska ◽  
Harun Bayraktar ◽  
Jon Goering ◽  
...  
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Woven Composites ◽  
Finite Element Models ◽  
The Matrix ◽  
3D Woven Composites ◽  
The Difference ◽  
Resin Curing

Finite element models of 3D woven composites are developed to predict possible microcracking of the matrix during curing. A specific ply-to-ply weave architecture for carbon fiber reinforced epoxy is chosen as a benchmark case. Two approaches to defining the geometry of reinforcement are considered. One is based on the nominal description of composite, and the second involves fabric mechanics simulations. Finite element models utilizing these approaches are used to calculate the overall elastic properties of the composite, and predict residual stresses due to resin curing. It is shown that for the same volume fraction of reinforcement, the difference in the predicted overall in-plane stiffness is on the order of 10%. Numerical model utilizing the fabric mechanics simulations predicts lower level of residual stresses due to curing, as compared to nominal geometry models.

scholarly journals Multiscale Analysis of Mechanical Properties of 3D Orthogonal Woven Composites with Randomly Distributed Voids

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5247
Author(s):  
Yaohua Gong ◽  
Tao Huang ◽  
Xun’an Zhang ◽  
Yongyong Suo ◽  
Purong Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Multiscale Analysis ◽  
Three Dimensional ◽  
Woven Composites ◽  
Manufacturing Processes ◽  
Design Basis ◽  
Void Defects ◽  
3D Woven Composites ◽  
3D Orthogonal Woven

Voids are common defects in 3D woven composites because of the complicated manufacturing processes of the composites. In this study, a micro–meso multiscale analysis was conducted to evaluate the influence of voids on the mechanical properties of three-dimensional orthogonal woven composites. Statistical analysis was implemented to calculate the outputs of models under the different scales. A method is proposed to generate the reasonable mechanical properties of the microscale models considering randomly distributed voids and fiber filaments. The distributions of the generated properties agree well with the calculated results. These properties were utilized as inputs for the mesoscale models, in which void defects were also considered. The effects of these defects were calculated and investigated. The results indicate that tensile and shear strengths were more sensitive to the microscale voids, while the compressive strength was more influenced by mesoscale voids. The results of this study can provide a design basis for evaluating the quality of 3D woven composites with void defects.

A volumetric three-dimensional evaluation of invasiveness of an endoscopic and microscopic approach for transmeatal visualisation of the middle ear

2021 ◽  
pp. 1-5
Author(s):  
A H A Baazil ◽  
J G G Dobbe ◽  
E van Spronsen ◽  
F A Ebbens ◽  
F G Dikkers ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Middle Ear ◽  
Three Dimensional ◽  
Endoscopic Approach ◽  
Microscopic Approach ◽  
Significant Difference ◽  
Computed Tomography Scans ◽  
The Difference ◽  
Group 2 ◽  
Group 1

Abstract Objective This study aimed to compare the necessary scutum defect for transmeatal visualisation of middle-ear landmarks between an endoscopic and microscopic approach. Method Human cadaveric heads were used. In group 1, middle-ear landmarks were visualised by endoscope (group 1 endoscopic approach) and subsequently by microscope (group 1 microscopic approach following endoscopy). In group 2, landmarks were visualised solely microscopically (group 2 microscopic approach). The amount of resected bone was evaluated via computed tomography scans. Results In the group 1 endoscopic approach, a median of 6.84 mm3 bone was resected. No statistically significant difference (Mann–Whitney U test, p = 0.163, U = 49.000) was found between the group 1 microscopic approach following endoscopy (median 17.84 mm3) and the group 2 microscopic approach (median 20.08 mm3), so these were combined. The difference between the group 1 endoscopic approach and the group 1 microscopic approach following endoscopy plus group 2 microscopic approach (median 18.16 mm3) was statistically significant (Mann–Whitney U test, p < 0.001, U = 18.000). Conclusion This study showed that endoscopic transmeatal visualisation of middle-ear landmarks preserves more of the bony scutum than a microscopic transmeatal approach.

scholarly journals A comparison of animated versus static images in an instructional multimedia presentation

2016 ◽  
Vol 40 (2) ◽  
pp. 201-205 ◽  
Author(s):  
C. J. Daly ◽  
J. M. Bulloch ◽  
M. Ma ◽  
D. Aidulis
Keyword(s):  
Student Satisfaction ◽  
Undergraduate Students ◽  
Three Dimensional ◽  
The Other ◽  
Multimedia Presentation ◽  
Still Images ◽  
Significant Difference ◽  
Essay Question ◽  
The Difference ◽  
Video Compositing

Sophisticated three-dimensional animation and video compositing software enables the creation of complex multimedia instructional movies. However, if the design of such presentations does not take account of cognitive load and multimedia theories, then their effectiveness as learning aids will be compromised. We investigated the use of animated images versus still images by creating two versions of a 4-min multimedia presentation on vascular neuroeffector transmission. One version comprised narration and animations, whereas the other animation comprised narration and still images. Fifty-four undergraduate students from level 3 pharmacology and physiology undergraduate degrees participated. Half of the students watched the full animation, and the other half watched the stills only. Students watched the presentation once and then answered a short essay question. Answers were coded and marked blind. The “animation” group scored 3.7 (SE: 0.4; out of 11), whereas the “stills” group scored 3.2 (SE: 0.5). The difference was not statistically significant. Further analysis of bonus marks, awarded for appropriate terminology use, detected a significant difference in one class (pharmacology) who scored 0.6 (SE: 0.2) versus 0.1 (SE: 0.1) for the animation versus stills group, respectively ( P = 0.04). However, when combined with the physiology group, the significance disappeared. Feedback from students was extremely positive and identified four main themes of interest. In conclusion, while increasing student satisfaction, we do not find strong evidence in favor of animated images over still images in this particular format. We also discuss the study design and offer suggestions for further investigations of this type.

scholarly journals A Comprehensive Study on the Mechanical Properties of Different 3D Woven Carbon Fiber-Epoxy Composites

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2765
Author(s):  
Qiaole Hu ◽  
Hafeezullah Memon ◽  
Yiping Qiu ◽  
Wanshuang Liu ◽  
Yi Wei
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Woven Composites ◽  
Thickness Direction ◽  
Woven Composite ◽  
Fiber Volume ◽  
3D Woven Composites ◽  
Accurate Comparison ◽  
3D Orthogonal Woven ◽  
Carbon Fiber Epoxy

In this work, the tensile, compressive, and flexural properties of three types of 3D woven composites were studied in three directions. To make an accurate comparison, three 3D woven composites are made to have the same fiber volume content by controlling the weaving parameters of 3D fabric. The results show that the 3D orthogonal woven composite (3DOWC) has better overall mechanical properties than those of the 3D shallow straight-joint woven composite (3DSSWC) and 3D shallow bend-joint woven composite (3DSBWC) in the warp direction, including tension, compression, and flexural strength. Interestingly their mechanical properties in the weft direction are about the same. In the through-thickness direction, however, the tensile and flexural strength of 3DOWC is about the same as 3DSBW, both higher than that of 3DSSWC. The compressive strength, on the other hand, is mainly dependent on the number of weft yarns in the through-thickness direction.

scholarly journals A Novel Three-Dimensional Vector Analysis of Axial Globe Position in Thyroid Eye Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jie Guo ◽  
Jiang Qian ◽  
Yifei Yuan ◽  
Rui Zhang ◽  
Wenhu Huang
Keyword(s):  
Three Dimensional ◽  
Thyroid Eye Disease ◽  
Eye Disease ◽  
Vector Method ◽  
Significant Difference ◽  
The Difference ◽  
Ct Data ◽  
Ct Measurement ◽  
Geometrical Equation ◽  
Corneal Apex

Purpose. To define a three-dimensional (3D) vector method to describe the axial globe position in thyroid eye disease (TED).Methods. CT data from 59 patients with TED were collected and 3D images were reconstructed. A reference coordinate system was established, and the coordinates of the corneal apex and the eyeball center were calculated to obtain the globe vectorEC→. The measurement reliability was evaluated. The parameters ofEC→were analyzed and compared with the results of two-dimensional (2D) CT measurement, Hertel exophthalmometry, and strabismus tests.Results. The reliability ofEC→measurement was excellent. The difference betweenEC→and 2D CT measurement was significant (p=0.003), andEC→was more consistent with Hertel exophthalmometry than with 2D CT measurement (p<0.001). There was no significant difference betweenEC→and Hirschberg test, and a strong correlation was found betweenEC→and synoptophore test. When one eye had a larger deviation angle than its fellow, its corneal apex shifted in the corresponding direction, but the shift of the eyeball center was not significant. The parameters ofEC→were almost perfectly consistent with the geometrical equation.Conclusions. The establishment of a 3D globe vector is feasible and reliable, and it could provide more information in the axial globe position.

Micromechanical Modeling for the Evaluation of Elastic Moduli of Woven Composites

2012 ◽  
Vol 525-526 ◽  
pp. 73-76 ◽  
Author(s):  
Daisei Abe ◽  
Omar Bacarreza ◽  
M.H. Aliabadi
Keyword(s):  
Mechanical Properties ◽  
Numerical Models ◽  
Impact Resistance ◽  
Textile Composites ◽  
Woven Composites ◽  
Micromechanical Modeling ◽  
Unit Cells ◽  
3D Woven Composites ◽  
Predicted Values ◽  
Complex Architecture

Textile composites have increasingly been used as a structural material because of their balanced properties, higher impact resistance, and easier handling and fabrication compared with unidirectional composites. However, the complex architecture of textile composites leads to difficulties in predicting the response in spite of the fact that there is the need to determine mechanical properties in product design. Micromechanical analysis, using the Finite Element Method, was conducted in order to evaluate the effective mechanical properties of plain woven and 3D woven composites. In this study, numerical models of unit cells were used and it is shown that the predicted values of homogenized mechanical properties using the developed procedure were in good agreement with experimental results.

The Effect of the Structural Parameters of 3D Orthogonal Woven Composites on their Impact Responses under Different Modes of Impact

2018 ◽  
Vol 786 ◽  
pp. 215-223 ◽  
Author(s):  
Mohamad Midani ◽  
Abde Fattah Seyam ◽  
Mark Pankow
Keyword(s):  
Structural Parameters ◽  
Impact Resistance ◽  
Three Dimensional ◽  
Charpy Impact ◽  
Woven Composites ◽  
Weaving Technology ◽  
Impact Responses ◽  
3D Orthogonal Woven ◽  
The Impact ◽  
3D Weaving

Development of three-dimensional (3D) weaving technology introduced new and enhanced features to the 2D weaving technology. 3D Orthogonal Woven (3DOW) preforms have a through-thickness yarn component that significantly enhances the impact resistance and delamination resistance. In this study, a range of 3DOW E-glass preforms were woven using 3D weaving technology and then converted into composites, using vacuum assisted resin transfer molding technology. The composite samples had varying structural parameters, such as, number of Y-yarn layers, X-yarn pick density, Z-yarn interlacing pattern. The purpose was to study the effect of changing those structural parameters on the different impact responses of the 3DOW composites under different modes of impact, namely, tup, Izod and Charpy impact. The study indicated that, the number of Y-yarn layers, had the most significant effect on the total tup, Izod, and Charpy impact energies. The X-yarn pick density, had slight effect on the three modes of impact, while the Z-yarn weave design only had a slight significant effect on the tup and Charpy impact energy.

Pointing the Foot Without Sickling: An Examination of Ankle Movement During Jumping

2015 ◽  
Vol 30 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Danielle N Jarvis ◽  
Kornelia Kulig
Keyword(s):  
Plantar Flexion ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Foot And Ankle ◽  
Vector Coding ◽  
Dance Training ◽  
Significant Difference ◽  
Ankle Movement ◽  
The Difference ◽  
Coordination Patterns

The sauté is a relatively simple dance jump that can be performed by both highly skilled dancers and non-dancers. However, there are characteristics of jumping unique to trained dancers, especially in terms of foot and ankle movement during flight. Dancers are trained not to “sickle,” or to avoid the anatomically coupled ankle inversion that occurs with plantar flexion, maintaining the appearance of a straight line through the lower leg and foot. The purpose of this study was to examine ankle movements in elite dancers compared to non-dancers. Twenty healthy females, 10 with no prior dance training and 10 professional dancers, performed 20 consecutive sautés while three-dimensional kinematic data were collected. Sagittal and frontal plane kinematics were calculated and vector coding methods were used to quantify coordination patterns within the ankle in the sagittal and frontal planes. This pattern was chosen for analysis to identify the avoidance of a sickled foot by trained dancers. Peak ankle positions and coordination patterns between groups were examined using independent t-tests (a<0.05). Dancers demonstrated greater peak plantar flexion (p<0.01) and less change in ankle angle during the flight phase (p=0.01), signifying holding the pointed foot position during flight. There was no statistically significant difference in sagittal and frontal plane ankle coupling (p=0.15); however, the Cohen’s d effect size for the difference in coupling was medium-to-large (0.73). Dynamic analysis of the foot and ankle during jumping demonstrates how elite dancers achieve the aesthetic requirements of dance technique.

Progressive damage modelling and experimental investigation of three-dimensional orthogonal woven composites with tilted binder

2019 ◽  
Vol 50 (1) ◽  
pp. 70-97 ◽  
Author(s):  
Wei Tao ◽  
Ping Zhu ◽  
Di Wang ◽  
Changhu Zhao ◽  
Zhao Liu
Keyword(s):  
Carbon Fiber ◽  
Three Dimensional ◽  
Fiber Composites ◽  
Unit Cell ◽  
Matrix Cracking ◽  
Woven Composites ◽  
Carbon Fiber Composites ◽  
Progressive Damage ◽  
Damage Initiation ◽  
3D Orthogonal Woven

This paper investigates the tensile properties of 3D orthogonal woven carbon fiber composites with tilted binder by experiment and simulation. The tensile failure strain and fracture mode of this composite show distinguished discrepancy with idealized 3D orthogonal woven composites experimentally. In order to explain this specific failure mechanism, a unit cell finite element model incorporated with damage models of constituents is established to reproduce the damage initiation and propagation of 3D orthogonal woven composites with tilted binder during tensile test. A three-dimensional failure criterion based on Hashin's criterion and Pinho's criterion is utilized to describe the progressive damage of yarns, while the non-linear behavior of the matrix is predicted by Drucker-Prager yield criterion. Besides, a traction-separation law is applied to predict the damage of yarn-matrix interface. The proposed unit cell model is correlated and validated by global stress–strain curves, DIC full-field strain distributions and modulus history curve. The damage evolution process of 3D orthogonal woven carbon fiber composites with tilted binder, including fiber tow failure, matrix cracking, and interfacial debonding, is recorded and investigated by the modulus history curve from simulation.

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