scholarly journals Discrete Element Analysis of the Strength Anisotropy of Fiber-Reinforced Sands Subjected to Direct Shear Load

2020 ◽  
Vol 10 (11) ◽  
pp. 3693
Author(s):  
Linxian Gong ◽  
Lei Nie ◽  
Yan Xu
Keyword(s):  
Fiber Orientation ◽  
Tensile Force ◽  
Orientation Angle ◽  
Discrete Element ◽  
Soil Reinforcement ◽  
Direct Shear ◽  
Strength Anisotropy ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Fiber Orientation Angle

Soil reinforcement with natural or synthetic fibers enhances its mechanical behavior in various applications. Fiber-reinforced sands (FRS) can be relatively anisotropic because of the fiber self-weight and the compaction technique. However, the microscopic mechanisms underlying the anisotropy are still poorly understood. This study used a discrete element approach to analyze the microscopic mechanisms underlying the strength anisotropy of FRS due to fiber orientation. Analysis of contact networks revealed that the optimum fiber orientation angle is perpendicular to the main direction of strong contact force in direct shear testing. These fibers produced the largest increase in shear zone thickness, normal force around the fiber body, effective contact area, tensile force along fibers, and energy storage/dissipation. This study is valuable for further understanding of the mechanical behaviors of FRS.

Numerical Simulation of the Orthogonal Cutting of Carbon Fiber Reinforced Composite Material

2014 ◽  
Vol 887-888 ◽  
pp. 1246-1250 ◽  
Author(s):  
Zhi Kai Li ◽  
Dong Lu ◽  
Qiang Wang ◽  
Yong Bo Wu
Keyword(s):  
Carbon Fiber ◽  
Fiber Orientation ◽  
Orthogonal Cutting ◽  
Orientation Angle ◽  
Surface Damage ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Fiber Orientation Angle ◽  
Carbon Fiber Reinforced

This work is focused on the study of orthogonal cutting of carbon fiber reinforced composite. A model based on finite element was developed. Through defining ultimate stresses of fiber tension cracking and fiber compression bucking, ultimate stresses of matrix longitudinal tensile and shear damage. Cutting forces obtained from the FE simulation matches well with the experimental observations. Than analysis cracking and crushing phenomenon of matrix in different fiber orientation, the influence of fiber orientation on sub-surface damage was studied, it shows that the cracking of sub-surface damage value increased with the increase of fiber orientation angle.

The effects of cutouts on buckling behavior of composite plates

2012 ◽  
Vol 19 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Ahmet Erkliğ ◽  
Eyüp Yeter
Keyword(s):  
Fiber Orientation ◽  
Polymer Matrix Composites ◽  
Orientation Angle ◽  
Composite Plates ◽  
Buckling Load ◽  
Matrix Composites ◽  
Element Analysis ◽  
Buckling Loads ◽  
Buckling Behavior ◽  
Fiber Orientation Angle

AbstractCutouts such as circular, rectangular, square, elliptical, and triangular shapes are generally used in composite plates as access ports for mechanical and electrical systems, for damage inspection, to serve as doors and windows, and sometimes to reduce the overall weight of the structure. This paper addresses the effects of different cutouts on the buckling behavior of plates made of polymer matrix composites. To study the effects of cutouts on buckling, loaded edges are taken as fixed and unloaded edges are taken as free. Finite element analysis is also performed to predict the effects of different geometrical cutouts, orientations, and position of cutouts on the buckling behavior. The results show that fiber orientation angle and cutout sizes are the most important parameters on the buckling loads. For all types of cutouts the buckling loads decrease dramatically by increasing the fiber orientation angle. It is observed that minimum buckling load is reached when 45° fiber angle is used, and after this angle critical buckling load begins to increase. Also, it is concluded that while fiber orientation angle is 0°, elliptical cutout has the highest buckling load and while fiber orientation angle is 45°, circular cutout has the highest buckling load.

Thermal characteristics of unidirectional carbon fiber reinforced polymer laminates during orthogonal cutting

2018 ◽  
Vol 37 (13) ◽  
pp. 905-916 ◽  
Author(s):  
Qinglong An ◽  
Jie Chen ◽  
Xiaojiang Cai ◽  
Tingting Peng ◽  
Ming Chen
Keyword(s):  
Carbon Fiber ◽  
Fiber Orientation ◽  
Cutting Temperature ◽  
Orientation Angle ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Fiber Orientation Angle ◽  
Carbon Fiber Reinforced

Carbon fiber reinforced polymer has been used as a major material for primary load-bearing structural components in aviation industry. But its poor heat resistance is an important factor affecting the machining performance, because high cutting temperature above glass transition temperature of resin matrix (normally 300°C or below) may lead to the degradation of the resin matrix. In this study, orthogonal machining experiments were conducted to investigate the effects of cutting parameters, cutting tool geometric parameters, and material parameters on cutting temperature, and the prediction model of cutting temperature about fiber orientation angle ( θ) was built. Cutting temperature was measured by semiartificial thermocouple method. The experimental results revealed that the influence of cutting parameters on cutting temperature was not affected by fiber orientation angle of carbon fiber reinforced polymer. Cutting tool geometric parameters have little effect on cutting temperature. Unlike metal materials, cutting temperature was greatly influenced by θ. Cutting temperature for θ < 90° was significantly higher than that for θ > 90°. The maximum temperature occurred at θ = 90°. The influence of fiber orientation angle was shown in two aspects: changing the springback of unidirectional-carbon fiber reinforced polymer laminates in cutting process, changing material removal mechanism, which affected cutting temperature eventually.

Comparison of Intensity Method and Counting Method in Measurement of Fiber Orientation Angle Distribution Using Image Processing

2007 ◽  
Vol 544-545 ◽  
pp. 207-210
Author(s):  
Jin Woo Kim ◽  
Dong Gi Lee
Keyword(s):  
Mechanical Properties ◽  
Image Processing ◽  
Fiber Orientation ◽  
Orientation Angle ◽  
Intensity Difference ◽  
Angle Distribution ◽  
Fiber Reinforced ◽  
Counting Method ◽  
Fiber Orientation Angle ◽  
Distribution State

The fiber reinforced composites has high specific strength and stiffness than metallic material and are an anisotropic material whose mechanical properties, such as strength and elasticity, change with their fiber orientation state, the fiber length, the fiber aspect ratio, fiber mat structure, etc. Above all, the fiber orientation angle distribution state of fiber reinforced composite is fundamental element of mechanical properties. So, many researches on this element have been conducted by means of nondestructive method currently. The fiber distribution state is measured by intensity difference of pixel using image processing and these methods are intensity method by calculating of intensity value of pixel and counting method by calculating of fiber quantity. In this research, the fiber orientation simulation picture was constructed by plotter according to change of fiber’s diameter, length and orientation. The fiber orientation distribution state was measured by this intensity information. The fiber orientation angle distribution state measured by intensity method and counting method was compared with fiber orientation function calculation value.

Buckling characteristics of cut-out borne composite stiffened hyperbolic paraboloid shell panel

2021 ◽  
pp. 146442072110058
Author(s):  
Sarmila Sahoo
Keyword(s):  
Finite Element ◽  
Orientation Angle ◽  
Buckling Load ◽  
Benchmark Problems ◽  
Hyperbolic Paraboloid ◽  
Element Analysis ◽  
Load Effect ◽  
Global Buckling ◽  
Fiber Orientation Angle ◽  
Shell Panel

The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.

Minimize the Deflection of Laminated Composite Plates under the External Load Using Fiber Orientation Angle

2014 ◽  
Vol 709 ◽  
pp. 144-147
Author(s):  
Ying Tao Chen ◽  
Song Xiang ◽  
Wei Ping Zhao
Keyword(s):  
Fiber Orientation ◽  
External Load ◽  
Optimization Problem ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Composite Plates ◽  
Load Optimization ◽  
Fiber Orientation Angle ◽  
Optimization Parameters

Optimization of fiber orientation angle is studied to minimize the deflection of the laminated composite plates by the genetic algorithm. The objective function of optimization problem is the minimum deflection of laminated composite plates under the external load; optimization parameters are fiber orientation angle of laminated composite plates. The results for the optimal fiber orientation angle and the minimum deflection of the 4-layer plates are presented to demonstrate the validity of present method.

scholarly journals Optimization of Laminated Composite Plates for Maximum Biaxial Buckling Load

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Pham Dinh Nguyen ◽  
Quang-Viet Vu ◽  
George Papazafeiropoulos ◽  
Hoang Thi Thiem ◽  
Pham Minh Vuong ◽  
...  
Keyword(s):  
Fiber Orientation ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Optimization Procedure ◽  
Composite Plates ◽  
Buckling Load ◽  
Biaxial Compression ◽  
Laminated Composite Plates ◽  
Design Variables ◽  
Fiber Orientation Angle

This paper proposes an optimization procedure for maximization of the biaxial buckling load of laminated composite plates using the gradient-based interior-point optimization algorithm. The fiber orientation angle and the thickness of each lamina are considered as continuous design variables of the problem. The effect of the number of layers, fiber orientation angles, thickness and length to thickness ratios on the buckling load of the laminated composite plates under biaxial compression is investigated. The effectiveness of the optimization procedure in this study is compared with previous works.

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