A Methodology for Synthesizing High-Performance Robots Fabricated With Optimally Tailored Composite Laminates

1987 ◽  
Vol 109 (1) ◽  
pp. 74-86 ◽  
Author(s):  
C. K. Sung ◽  
B. S. Thompson
Keyword(s):  
Composite Laminates ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Fiber Volume ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Robot Arms ◽  
The Matrix

An essential ingredient of the next generation of robotic manipulators will be high-strength lightweight arms which promise high-performance characteristics. Currently, a design methodology for optimally synthesizing these essential robotic components does not exist. Herein, an approach is developed for addressing this void in the technology-base by integrating state-of-the-art techniques in both the science of composite materials and also the science of flexible robotic systems. This approach is based on the proposition that optimal performance can be achieved by fabricating robot arms with optimal cross-sectional geometries fabricated with optimally tailored composite laminates. A methodology is developed herein which synthesizes the manufacturing specification for laminates which are specifically tailored for robotic applications in which both high-strength, high-stiffness robot arms are required which also possess high material damping. The parameters in the manufacturing specification include the fiber-volume fraction, the matrix properties, the fiber properties, the ply layups, the stacking sequence and the ply thicknesses. This capability is then integrated within a finite-element methodology for analyzing the dynamic response of flexible robots. An illustrative example demonstrates the approach by simulating the three-dimensional elastodynamic response of a robot subjected to a prescribed spatial maneuver.

An Optimal Design of Composite Robot Arms

1989 ◽  
Author(s):  
C. K. Sung ◽  
S. S. Shyl
Keyword(s):  
Composite Laminates ◽  
High Performance ◽  
Design Methodology ◽  
Volume Fraction ◽  
Robot Manipulator ◽  
High Strength ◽  
Fiber Volume ◽  
Low Mass ◽  
Design Requirements ◽  
Fast Settling

Abstract A design methodology considering the issue of manufacturability, in particular, is presented for synthesizing high-performance articulating robotic systems fabricated with optimally-tailored composite laminates. By optimally specifying the types of fiber, matrix, stacking sequence, fiber volume fraction, fiber layups, etc., the synthesized composite material may possess significantly superior characteristics such as high damping, high stiffness, high strength and low mass. In accordance with the design requirements, the minimum deflection during articulating motion or the fast settling time after the power stopped, the design objectives and constraint conditions were specified. As an illustrative example, a two-link robot manipulator fabricated with aforementioned composite laminates is employed for demonstrating the proposed design methodology.

An advanced geometrical model for laminated woven fabrics using Lamé exponents with enhanced accuracy

2017 ◽  
Vol 52 (11) ◽  
pp. 1443-1455
Author(s):  
Mike Mühlstädt ◽  
Wolfgang Seifert ◽  
Matthias ML Arras ◽  
Stefan Maenz ◽  
Klaus D Jandt ◽  
...  
Keyword(s):  
High Performance ◽  
Volume Fraction ◽  
Level Structure ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Woven Fabrics ◽  
Fiber Volume ◽  
Meso Level ◽  
Precise Prediction ◽  
Microscopy Images

Three-dimensional stiffness tensors of laminated woven fabrics used in high-performance composites need precise prediction. To enhance the accuracy in three-dimensional stiffness tensor prediction, the fabric’s architecture must be precisely modeled. We tested the hypotheses that: (i) an advanced geometrical model describes the meso-level structure of different fabrics with a precision higher than established models, (ii) the deviation between predicted and experimentally determined mean fiber-volume fraction ( cf) of laminates is below 5%. Laminates of different cf and fabrics were manufactured by resin transfer molding. The laminates’ meso-level structure was determined by analyzing scanning electron microscopy images. The prediction of the laminates’ cf was improved by up to 5.1 vol% ([Formula: see text]%) compared to established models. The effect of the advanced geometrical model on the prediction of the laminate’s in-plane stiffness was shown by applying a simple mechanical model. Applying an advanced geometrical model may lead to more accurate simulations of parts for example in automotive and aircraft.

Resin Infusion of Triaxially Braided Preforms With Through-the-Thickness Reinforcement

2001 ◽  
Author(s):  
Jay R. Sayre ◽  
Alfred C. Loos
Keyword(s):  
Composite Structures ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Element Model ◽  
Manufacturing Cost ◽  
Fiber Volume ◽  
Resin Infusion ◽  
Infiltration Process ◽  
High Fiber

Abstract Vacuum assisted resin transfer molding (VARTM) has shown potential to significantly reduce the manufacturing cost of high-performance aerospace composite structures. In this investigation, high fiber volume fraction, triaxially braided preforms with through-the-thickness stitching were successfully resin infiltrated by the VARTM process. The preforms, resin infiltrated with three different resin systems, produced cured composites that were fully wet-out and void free. A three-dimensional finite element model was used to simulation resin infusion into the preforms. The predicted flow patterns agreed well with the flow pattern observed during the infiltration process. The total infiltration times calculated using the model compared well with the measured times.

Permeability Calculations in Three-Dimensional Fiber Networks

2008 ◽  
Author(s):  
T. Stylianopoulos ◽  
A. Yeckel ◽  
J. J. Derby ◽  
X. J. Luo ◽  
M. S. Shephard ◽  
...  
Keyword(s):  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Volume Averaging ◽  
Creeping Flow ◽  
Fibrous Media ◽  
Fiber Volume ◽  
Fiber Networks ◽  
Flow Through ◽  
High Performance Computers

The study of creeping flow in fibrous media is of considerable interest in many biological and biomedical applications. There is little work, however, on permeability calculations in three-dimensional random networks. Computational power is now sufficient to calculate permeabilities directly by constructing artificial fiber networks and simulating flow through them. Even with today’s high-performance computers, however, such an approach would be infeasible for large simulations. It is therefore necessary to develop a correlation based on fiber volume fraction, radius and orientation, preferably by incorporating previous studies on isotropic or structured networks. In this work, the direct calculations were performed, using the finite element method, on networks with varying degrees of orientation, and combinations of results for flow parallel and perpendicular to a single fiber or an array thereof, using a volume averaging theory, were compared to the detailed analysis.

Improving UV Resistance of Fibers: Idealized Computational Model Predicting the Distribution of UV Blocking Cylindrical Nanoparticles in Protective Polymeric Layer

2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000
Author(s):  
Abdelfattah Mohamed Seyam ◽  
Rahul Vallabh ◽  
Ahmed H. Hassanin
Keyword(s):  
Aspect Ratio ◽  
Computational Model ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Uv Protection ◽  
Uv Resistance ◽  
Premature Failure ◽  
Areal Coverage

High strength fibers such as PBO and Kevlar are used to produce composites, bulletproof vests, tendons of giant scientific balloons, and other high performance products. These fibers, however, are known to degrade upon exposure to Ultraviolet (UV) radiation which causes premature failure of the end-products. Improving UV resistance of high strength fibers like PBO through methods such as adding UV inhibiting particles during filament spinning or dyeing/coating process is not only extremely difficult, but often fails to provide the adequate UV protection. As an alternative to conventional approaches, UV protection of high performance yarns/braids can be effectively achieved by covering them with a polymeric sheath containing dispersed UV inhibiting nanoparticles. In this work, a computational model was developed to optimize critical factors such as thickness (weight) of the protective sheath and the amount of UV blockers for a given particle size, which influence the UV protective efficiency of the sheath. In order to simulate three-dimensional dispersion of nanoparticles in a polymer matrix, the model considers a random distribution of cylindrical nanoparticles of different size, aspect ratio, and volume fraction in a three-dimensional volume of protective sheath of a given length, width, and thickness. 2D visualization and image analysis techniques were utilized to determine the area projected by the particles on the x-y plane (areal coverage provided by nanoparticles). The areal coverage values obtained from the model were found to be higher than the experimental results due to the agglomeration of nanoparticles in the sheath caused during the polymer compounding process. However, the purpose of the model is to serve as a benchmarking tool to aid in the design and development of UV protective sheaths and films, and not to estimate absolute UV protection values. Analysis of the relationship between areal coverage and various input parameters in the model show that areal coverage increases with an increase in particle volume fraction and film thickness, and a decrease in particle diameter and length. It was also found that areal coverage was more significantly influenced by particle aspect ratio than by particle length.

scholarly journals Effects of Hooked-End Steel Fiber Geometry and Volume Fraction on the Flexural Behavior of Concrete Pedestrian Decks

2019 ◽  
Vol 9 (6) ◽  
pp. 1241 ◽  
Author(s):  
Seung-Jung Lee ◽  
Doo-Yeol Yoo ◽  
Do-Young Moon
Keyword(s):  
Flexural Strength ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Flexural Behavior ◽  
Multiple Cracks ◽  
Fiber Volume ◽  
Volume Fractions ◽  
Steel Rebars

This study investigates the effects of hooked-end fiber geometry and volume fraction on the flexural behavior of concrete pedestrian decks. To achieve this, three different fiber geometries, i.e., three-dimensional (3D), four-dimensional (4D), and five-dimensional (5D), and volume fractions of 0.37%, 0.6%, and 1.0% were considered. Test results indicate that a higher number of hook ends can more effectively enhance the flexural strength and flexural strength margin at all volume fractions than a lower number, so that the order of effectiveness of hooked-end fibers on the flexural strength parameters was as follows: 5D > 4D > 3D. To satisfy the ductility index of 0.39, the amounts of 3D, 4D, and 5D hooked steel fibers should be in the range of 0.98%‒1.10%. Moreover, at a fiber volume fraction of 1.0%, only multiple cracking behaviors were observed, and the numerical results indicated that the volume fraction should be equal to 1.0% to guarantee a deflection-hardening response of pedestrian decks, regardless of the hooked-end fiber geometry. Consequently, a 1.0% by volume of hooked-end steel fiber is recommended to replace the minimum longitudinal steel rebars and guarantee a ductile flexural behavior with multiple cracks for pedestrian decks made of high-strength concrete.

Numerical Generation Technology for Three-Dimensional Structure of High-Performance Fiber Bundle

2011 ◽  
Vol 332-334 ◽  
pp. 1024-1027
Author(s):  
Lei Li ◽  
Li Chen ◽  
Jin Chao Li
Keyword(s):  
Fiber Bundle ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Lateral Compression ◽  
Fiber Volume ◽  
Three Dimensional Structure ◽  
High Performance Fiber ◽  
Compression Mechanism

The three-dimensional structure of high-performance fiber bundles are of paramount importance for their study in lateral compression mechanism. Modeling of their true morphologies is still fields of focus research, yet to be exhausted. In this paper, ANSYS were utilized to develop three-dimensional numerical model of fiber bundle on the computer in the way of simulation. This approach is enabled by the finite element packages. It is possible to simulate the true material morphology directly. The key issues of the simulation are to keep fiber volume fraction always a constant value and to ensure no intersection between fibers. This work can simulate the stochastic generation-growth of high-performance fiber bundle and reproduce morphology of fiber bundle on micron scale well and thereby provide reliable information for the study on the lateral compression mechanism in the future.

Design and Manufacture of Three Dimensional Integrated Braided Composite Tube with Flange

2010 ◽  
Vol 34-35 ◽  
pp. 1393-1396 ◽  
Author(s):  
Guang Wei Chen ◽  
Jia Lu Li
Keyword(s):  
High Performance ◽  
Volume Fraction ◽  
Research Result ◽  
Three Dimensional ◽  
Compressive Force ◽  
Fiber Volume ◽  
Braided Composite ◽  
Composite Tube ◽  
Design And Manufacture

In this paper, the design and manufacture technology of three dimensional(3D) integrated braided composite tube with flange are researched, including: braiding technology of 3D braided preform of tube with flange, the determination of process parameters of resin transfer molding(RTM) for 3D braided composite tube with flange, and the design of mould for consolidation of composite tube with flange. The fiber volume fraction of this component is calculated. The quality of composite tube with flange is good analyzed by ultrasonic A-scan. The maximum compressive force borne by composite tube flange is 56.65 kN, which has met the need of usage of 38 kN. The research result will provide a good way for designing and manufacturing high performance 3D integrated braided composite components with irregular shape.

scholarly journals Micro-buckling of carbon fibers in shape memory polymer composites under bending in the glass transition temperature region

2021 ◽  
Vol 8 (1) ◽  
pp. 96-108
Author(s):  
Nilesh Tiwari ◽  
AbdulHafiz A. Shaikh
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Polymer Composites ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Minimum Energy ◽  
Three Dimensional ◽  
Fiber Volume ◽  
Half Wavelength ◽  
The Matrix

Abstract The influence of a wide temperature range in the glass transition region of a shape memory polymer (SMP) matrix on micro-buckling of the fiber reinforcements in shape memory polymer composites (SMPC) under large bending deformation is described. Analytical expressions to estimate the strain energy, neutral strain surface, critical buckling surface and half wavelength of the buckled fibers in the SMPC are presented based on the minimum energy method. This study considers the reinforced fibers as three-dimensional elastic bodies and the matrix as a temperature stimulated flat plate. A comprehensive study was performed to understand the dynamic temperature behavior of the micro-buckled fibers and corresponding results were validated by previous works in the literature. The effects of fiber volume fraction and thickness of the SMPC plates on the half wavelength are also discussed along with the simultaneous influence of temperature on the parameters computed in the minimum energy analysis.

Ductility of Ultra-High Performance Concrete and its Correlation with Tensile Strength Increase

2015 ◽  
Vol 665 ◽  
pp. 21-24
Author(s):  
B.I. Bae ◽  
Hyun Ki Choi ◽  
Chang Sik Choi
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
High Strength ◽  
Reinforcement Ratio ◽  
Fiber Reinforced Concrete ◽  
Strength Increase ◽  
Ultra High Performance Concrete ◽  
Fiber Volume

In this study, ductility of members with ultra-high performance concrete was investigated using moment-curvature analysis for the verification of safety under large deformation of ultra-high performance concrete structural members. For the analysis of members with ultra-high performance concrete, mathematical stress-strain model was selected among the results conducted by other researchers on the compressive and tensile behavior of high strength concrete and fiber reinforced concrete. According to the investigation on ductility of members with ultra-high performance concrete, decrease of ductility was observed with increase of tensile strength of concrete under the same reinforcement ratio. Members with 2~3% of reinforcement ratio, which usually be used in the field engineering, show the decrease of ductility with increase of fiber volume fraction. As a results of parametric study, limitation of maximum reinforcement ratio ( or limitation of net tensile strain ) suggested by current design code is not safe when using ultra-high performance concrete.

Sign in / Sign up

Export Citation Format

Share Document