Numerical analysis of punch shear failure and stress characteristics of three-dimensional braided composite with different braiding angles

2019 ◽  
Vol 28 (9) ◽  
pp. 1418-1437
Author(s):  
Yuanyuan Li ◽  
Zhijuan Pan ◽  
Bohong Gu ◽  
Baozhong Sun
Keyword(s):  
Shear Failure ◽  
Shear Bands ◽  
Three Dimensional ◽  
Element Model ◽  
Scale Model ◽  
Strain Rates ◽  
Braided Composites ◽  
Braided Composite ◽  
Multi Scale ◽  
Braided Structure

This paper presents a multi-scale finite element model to calculate the stress field and analyze the punch shear failure of three-dimensional braided composite at high strain rates. The multi-scale model was established based on real braided structure taking the surface and corner braiding yarns into consideration. Constitutive material modeling and failure criterions were introduced into the model. Three braiding angles of 25°, 35°, and 45° were applied to reveal the relations between failure states and braided structure. The results showed that the punch shear failure states and stress distribution were greatly dependent on the strain rates and braiding angles. Nonuniform stress propagation resulted in shear bands and different formation paths were observed on the composite with different braiding angles. The ultimate failure of braided composite was determined by comprehensive action of compressive and tensile stress. In addition, the progressive damage of typical braiding yarns in different conditions was obtained from the modeling simulation. The three-dimensional braided composites with different braiding angles showed unique failure morphology. It was closely determined by the complex braided structures.

Enhancement of mechanical and electromagnetic absorbing properties of carbon/glass hybrid composites with a three-dimensional quasi-isotropic braided structure

2019 ◽  
Vol 89 (23-24) ◽  
pp. 4896-4905 ◽  
Author(s):  
Wei Fan ◽  
Lili Xue ◽  
Tongxue Wei ◽  
Jingjing Dong ◽  
Juanzi Li ◽  
...  
Keyword(s):  
Hybrid Composites ◽  
Glass Fibers ◽  
Three Dimensional ◽  
Laminated Composite ◽  
External Stress ◽  
Braided Composites ◽  
Braided Composite ◽  
Braided Structure ◽  
Electromagnetic Transmission ◽  
Ku Band

Two carbon/glass hybrid composites with different reinforced structures were designed and their mechanical and electromagnetic absorbing properties (EMAPs) were investigated in this paper. It was found that the tensile, bending, and double-notch shear strength of the three-dimensional (3D) quasi-isotropic (QI)-braided composite were 4.50%, 9.64%, and 14.29% higher than those of the QI-laminated composite, respectively. This was because Z-binder yarns in the 3D QI-braided composite can lock all yarn sets together to bear external stress and inhibit crack propagation in interlamination. The EMAPs of the 3D QI-braided composites were larger than that of the QI-laminated composite in the entire Ku band. This was because the Z-directional glass fibers in the 3D QI-braided composite were beneficial for electromagnetic transmission. The uniform arrangement of five sets of yarns (+45°, –45°, 90°, 0°, and Z-yarns) resulted in the 3D QI-braided composites having better QI-EMAPs and QI mechanical properties in plane and outstanding interlayer performance than the traditional carbon fiber laminated composite.

CNT Thin Film Network Failure due to Concentrated Current Loadings

2011 ◽  
Author(s):  
David A. Jack
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Response ◽  
Three Dimensional ◽  
Element Model ◽  
Scale Model ◽  
Lightning Strike ◽  
Similar System ◽  
Network Failure ◽  
Multi Scale

Polymer composite carbon nanotube (CNT) thin films have been hypothesized as a possible material for lightning strike protection for next generation aircraft structures. This study employs the author’s previously presented three-dimensional physics-based coupled thermal and electrical multi-scale model which constructs the non-deterministic nanostructure variations for a CNT thin film, and returns the bulk thermal and electrical response due to high electrical loadings. The key results of the present study are the presentation of a possible failure mechanism for CNT thin films under increasing electrical loadings. This paper discusses the nanoscale breakdown of the network conductivity using a quasi-static loading, and uses the nanoscale results in a macroscopic finite element model which couples resistive heating with thermal breakdown. The results are in reasonable agreement with those found in the literature for a similar system.

Finite element analyses on punch shear behaviors of three-dimensional braided composites at microstructure level

2016 ◽  
Vol 26 (7) ◽  
pp. 968-988 ◽  
Author(s):  
Yuanyuan Li ◽  
Wei Zhang ◽  
Rotich K Gideon ◽  
Bohong Gu ◽  
Baozhong Sun
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
High Strain ◽  
Three Dimensional ◽  
Rate Sensitivity ◽  
Element Model ◽  
Shear Loading ◽  
Composite Panel ◽  
Braided Composites ◽  
Braided Composite

The punch shear properties of three-dimensional carbon/epoxy braided composites were studied at quasi-static and high strain rates with finite element method at microstructure level. A microstructure model was developed to analyze the stress distribution and progressive damage of the braided composite panel with different thickness. The braiding yarns were considered as an elastic and transversely isotropic material. Ductile and shear criterion were used in finite element model to obtain the damage evolution. It was found that the braided composite exhibited high strain rate sensitivity under punch shear loading. The thickness influences the punch shear strength significantly. The braiding yarns at surface and corner parts have tensile and pullout failure modes, while at inner part have shear damage mode.

Three-dimensional Reconstruction of Microscopic Image Based on Multi-ST Algorithm

2020 ◽  
Vol 64 (2) ◽  
pp. 20506-1-20506-7
Author(s):  
Min Zhu ◽  
Rongfu Zhang ◽  
Pei Ma ◽  
Xuedian Zhang ◽  
Qi Guo
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Scale Model ◽  
Microscopic Image ◽  
Multi Scale ◽  
Gaussian Pyramid ◽  
Cost Aggregation ◽  
Dimensional Reconstruction ◽  
Image Pairs ◽  
Accurate Matching

Abstract Three-dimensional (3D) reconstruction is extensively used in microscopic applications. Reducing excessive error points and achieving accurate matching of weak texture regions have been the classical challenges for 3D microscopic vision. A Multi-ST algorithm was proposed to improve matching accuracy. The process is performed in two main stages: scaled microscopic images and regularized cost aggregation. First, microscopic image pairs with different scales were extracted according to the Gaussian pyramid criterion. Second, a novel cost aggregation approach based on the regularized multi-scale model was implemented into all scales to obtain the final cost. To evaluate the performances of the proposed Multi-ST algorithm and compare different algorithms, seven groups of images from the Middlebury dataset and four groups of experimental images obtained by a binocular microscopic system were analyzed. Disparity maps and reconstruction maps generated by the proposed approach contained more information and fewer outliers or artifacts. Furthermore, 3D reconstruction of the plug gauges using the Multi-ST algorithm showed that the error was less than 0.025 mm.

A novel synergistic multi-scale modeling framework to predict micro- and meso-scale damage behaviors of 2D triaxially braided composite

2021 ◽  
pp. 105678952110339
Author(s):  
Hongyong Jiang ◽  
Yiru Ren ◽  
Qiduo Jin
Keyword(s):  
Compressive Load ◽  
Scale Model ◽  
Modeling Framework ◽  
Braided Composite ◽  
Multi Scale ◽  
Scale Modeling ◽  
Bridge Model ◽  
Multi Scale Modeling ◽  
Transverse Damage ◽  
Meso Scale

A novel synergistic multi-scale modeling framework with a coupling of micro- and meso-scale is proposed to predict damage behaviors of 2D-triaxially braided composite (2DTBC). Based on the Bridge model, the internal stress and micro damage of constituent materials are respectively coupled with the stress and damage of tow. The initial effective elastic properties of tow (IEEP) used as the predefined data are estimated by micro-mechanics models. Due to in-situ effects, stress concentration factor (SCF) is considered in the micro matrix, exhibiting progressive damage accumulation. Comparisons of IEEP and strengths between the Bridge and Chamis’ theory are conducted to validate the values of IEEP and SCF. Based on the representative volume element (RVE), the macro properties and damage modes of 2DTBC are predicted to be consistent with available experiments and meso-scale simulation. Both axial and transverse damage mechanisms of 2DTBC under tensile or compressive load are revealed. Micro fiber and matrix damage accumulations have significant effects on the meso-scale axial and transverse damage of tows due to multi-scale coupling effects. Different from existing meso-/multi-scale models, the proposed multi-scale model can capture a crucial phenomenon that the transverse damage of tow is vulnerable to micro fiber fracture. The proposed multi-scale framework provides a robust tool for future systematic studies on constituent materials level to larger-scale aeronautical materials.

scholarly journals Analysis of Forces in Vibro-Impact and Hot Vibro-Impact Turning of Advanced Alloys

2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Machining Process ◽  
Strain Rates ◽  
Machining Processes ◽  
Machined Surface ◽  
Cutting Zone

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.

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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