Woven Nitinol Fabric Strips Characterized in Tension via Finite Element Analysis and Geometric Modeling

2019 ◽  
Author(s):  
Amanda Skalitzky ◽  
Caleb Petersen ◽  
Austin Gurley ◽  
David Beale
Keyword(s):  
Geometric Modeling ◽  
Room Temperature ◽  
Geometric Model ◽  
Small Strain ◽  
Woven Fabric ◽  
Analytical Models ◽  
Scanning Calorimetry ◽  
Element Analysis ◽  
Beam Elements ◽  
Nitinol Wire

Abstract Nitinol in the form of wires, tubes, and plates have been explored extensively; however, the characteristics of Nitinol as a woven fabric have so far been little-studied analytically. It would be easier to design such a fabric if conventional fabric models were known to apply to Nitinol fabrics, potentially with modifications required by Nitinol’s unique properties. A 25 mm wide Nitinol narrow fabric has been manufactured using traditional weaving equipment using a proprietary process that achieves a uniform and tight weave. Heat-treatment and straight shape-set is applied to a single Nitinol wire and the woven Nitinol fabric at 600°C for 30 minutes. The 0.25 mm Nitinol wire constituent was tested using differential scanning calorimetry (DSC) to determine the transition temperatures (Mf, Ms, As, and Af), which were found on average to be 54.5°C, 66.9°C, 88.7°C, and 103.5°C respectively. Both the Nitinol wire and fabric were tested in a temperature-controlled chamber (testing temperatures ranged from room temperature to 200°C) in which the tensile stress-strain characteristics were observed. It was determined that existing analytical models can be employed to accurately estimate the overall tensile stiffness of woven Nitinol fabrics in a small-strain regime. Additionally, it was confirmed that the tensile loading of woven Nitinol fabric can be modeled in MSC.Adams with beam elements. In combination with the geometric model presented, woven Nitinol fabric behavior can be predicted from the experimental behavior of the constituent Nitinol wire.

Prediction of Color Attributes Through Geometrical Modeling

2008 ◽  
Vol 12 (1) ◽  
pp. 19-31 ◽  
Author(s):  
Kavita Mathur ◽  
Abdel-Fattah M. Seyam ◽  
David Hinks ◽  
R. Alan Donaldson
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Subjective Evaluation ◽  
Woven Fabric ◽  
Warp Yarn ◽  
Color Selection ◽  
Cad System ◽  
System Operator ◽  
Color Mixing ◽  
Fabric Surface

Today, Jacquard woven fabric producers are able to digitally control each warp yarn individually, pre-program the variable pick density and speed for each filling yarn, and automatically change a pattern without stopping the weaving process. Jacquard CAD systems dramatically reduce the time to produce fabric from the artwork or target design The process of weave/color selection for each area of the pattern is, however, still highly dependent on the CAD system operator who works from a particular color gamut. Multiple weaving trials are required to get a sample that matches the original artwork since the process requires the designer‘s subjective evaluation. The lack of automatic selection of weaves/color matching prompts this research. This paper addresses the development of a geometric model for predicting the color contribution of each warp and filling yarn on the fabric surface in terms of construction parameters. The combination of geometric modeling and existing color mixing equations enables the prediction of the final color of different areas of a Jacquard pattern. The model was verified experimentally and a close agreement was found between a color mixing equation and the experimental measurements.

Design and analysis of a self-lubricating nuclear joint bearing above 320°C

2017 ◽  
Vol 69 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Jun Cao ◽  
Zhongwei Yin ◽  
Yuqing Cui ◽  
Hulin Li ◽  
Gengyuan Gao ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Design Methodology ◽  
Room Temperature ◽  
Thermal Structure ◽  
Woven Fabric ◽  
Safety Factors ◽  
Coupled Simulation ◽  
Element Analysis ◽  
Content Type ◽  
New Type

Purpose The purpose of this study was to solve the problem of most woven-fabric self-lubricating bearings that find it difficult to function at temperatures above 320°C, by designing a new type of new nuclear joint bearing. The results of this study will help designers to achieve accurate stress distribution, displacement deformation, fatigue life and damage of bearings. All of these can be a guide for designing self-lubricating joint bearings. Design/methodology/approach Finite element analysis is undertaken to simulate the new design bearings. To get the most appropriate and accurate results, the room temperature simulation (Simulation A), the modulus of elasticity that changes with temperature (Simulation B) and the thermal-structure-coupled simulation (Simulation C) are compared. The fatigue simulation is conducted to verify whether the self-lubricating method is reasonable and whether the bearing can function for over 60 years in an enclosed environment. Findings Stress distribution and displacement deformation of joint bearing can be accurately achieved via the thermal-structure coupled simulation. Work life and damage results have been achieved via the fatigue analysis, and the suggested working loads can be calculated via safety factors. Originality/value The newly designed joint bearing in which the graphite is laid on the outside of the inner ring functions and self-lubricates at temperatures above 320°C.

scholarly journals Carbon Fiber Laminates with Interlaminar Carbon Nanotubes

2020 ◽  
Vol 57 (1) ◽  
pp. 80-85
Author(s):  
Leandro Iorio ◽  
Loredana Santo ◽  
Fabrizio Quadrin ◽  
Denise Bellisario ◽  
David Benedetti ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Room Temperature ◽  
Woven Fabric ◽  
Resin Matrix ◽  
Compression Moulding ◽  
Scanning Calorimetry ◽  
Peeling Strength ◽  
Manufacturing Procedure

Carbon fibre reinforced (CFR) laminates were manufactured by prepreg lay-up and deposition of interlaminar carbon nanotubes (CNTs). An easy and innovative manufacturing procedure was used. CNTs were separated in solvent by ultrasonication, and poured on the woven fabric prepreg. Solvent evacuation was performed at low temperature, and dry functionalized prepregs were used for composite lamination. Laminates were cured by compression moulding on a heating plate. Peeling tests, differential scanning calorimetry (DSC), and dynamic mechanical analyses (DMA) were carried out on multiply samples with and without 1 wt% of interlaminar CNTs. Results show that the glass transition temperature of the resin matrix reduces because of the interaction with CNTs. Nevertheless, peeling strength shows 10% increase at room temperature.

scholarly journals Determination of Detachment Frequencies of Ripe Coffee Fruits (Coffea Arabica Var. Colombia) by Means of a Numerical and Experimental Approach

2019 ◽  
Author(s):  
Hector Andres Tinoco
Keyword(s):  
Coffea Arabica ◽  
Experimental Approach ◽  
Geometric Model ◽  
Numerical Approach ◽  
Analytical Models ◽  
Element Analysis ◽  
Ripening Stages ◽  
Dynamic Excitations ◽  
Coffea Arabica L

In this study, it is proposed an experimental and numerical approach to identify a bandwidth of harmonic frequencies where ripe fruits of Coffea arabica L. var. Colombia can be selectively stimulated. For this purpose, a geometric model was designed computationally to represent the topology of the coffee fruit-peduncle system in all ripening stages. Using analytical models and pseudo-experimental data, the mechanical properties were estimated to carry out a finite element analysis of the system. It was verified with a detachment model that fruits can be detached when a specific harmonic force (mechanical vibrations) is applied on the fruits in determined frequencies which correspond to the second vibration mode of the fruits. Results indicate that dynamic excitations between 130 to 150 Hz could detach only ripe fruits since fruits that were in other ripening stages were not stimulated until detachment in that bandwidth.

scholarly journals Internet-based Distributed Collaborative Engineering Analysis

2002 ◽  
Vol 10 (4) ◽  
pp. 341-348 ◽  
Author(s):  
Qiuli Sun ◽  
Kurt Gramoll
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Three Dimensional ◽  
Shared Environment ◽  
Engineering Analysis ◽  
Element Analysis ◽  
Team Members ◽  
Dimensional Finite Element ◽  
Actual Design ◽  
Three Dimensional Finite Element

This paper proposes an engineering analysis environment that allows remote users to conduct three-dimensional finite element analysis collaboratively through the Internet. Java and Java 3D were chosen to develop the working prototype due to their advantages of platform-independence and network supporting. The environment allows remote users to work collaboratively on the same analysis object simultaneously. It reads the geometric data generated by the collaborative geometric modeling environment. The user can interact directly with the geometric model to perform operations, such as applying, editing, and deleting boundary conditions and forces. The operations are propagated among the team members, which creates a distributed shared environment. The commands are transmitted instead of the generated data, and thus the network traffic associated with the collaboration is minimized. Different from classical server/client models,# the environment adopts a strategy in which the client-side application has full analysis capabilities while the server only manages communication. The essential features for distributed collaboration are discussed. The actual design consideration of the working prototype is presented to help illustrate the complexity and development of the collaborative environment. The environment is open to the public at www.vcity.ou.edu.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

Star-shaped arylacetylene resins derived from silicon

2020 ◽  
Vol 40 (8) ◽  
pp. 676-684
Author(s):  
Niping Dai ◽  
Junkun Tang ◽  
Manping Ma ◽  
Xiaotian Liu ◽  
Chuan Li ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Mechanical Test ◽  
Flexural Modulus ◽  
Mechanical Analysis ◽  
Reinforced Composites ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Structures And Properties ◽  
High Performance Resin

AbstractStar-shaped arylacetylene resins, tris(3-ethynyl-phenylethynyl)methylsilane, tris(3-ethynyl-phenylethynyl) phenylsilane, and tris (3-ethynyl-phenylethynyl) silane (TEPHS), were synthesized through Grignard reaction between 1,3-diethynylbenzene and three types of trichlorinated silanes. The chemical structures and properties of the resins were characterized by means of nuclear magnetic resonance, fourier-transform infrared spectroscopy, Haake torque rheomoter, differential scanning calorimetry, dynamic mechanical analysis, mechanical test, and thermogravimetric analysis. The results show that the melt viscosity at 120 °C is lower than 150 mPa⋅s, and the processing windows are as wide as 60 °C for the resins. The resins cure at the temperature as low as 150 °C. The good processabilities make the resins to be suitable for resin transfer molding. The cured resins exhibit high flexural modulus and excellent heat-resistance. The flexural modulus of the cured TEPHS at room temperature arrives at as high as 10.9 GPa. Its temperature of 5% weight loss (Td5) is up to 697 °C in nitrogen. The resins show the potential for application in fiber-reinforced composites as high-performance resin in the field of aviation and aerospace.

scholarly journals The effect of polyhedral oligomeric silsesquioxanes (POSSs) incorporation in ethylene-propylene-diene-terpolymer (EPDM): a thermal study

2021 ◽  
Author(s):  
Ignazio Blanco ◽  
Traian Zaharescu
Keyword(s):  
Room Temperature ◽  
Thermal Characterization ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Dsc Analysis ◽  
Γ Irradiation ◽  
Scanning Calorimetry ◽  
Ethylene Propylene ◽  
Oligomeric Silsesquioxane ◽  
Ethylene Propylene Diene Terpolymer ◽  
Dynamic Heating

AbstractA series of ethylene-propylene-diene-terpolymer (EPDM)/polyhedral oligomeric silsesquioxane (POSS) composites at different percentage of POSS were prepared and subjected to γ-irradiation. Both irradiated and non-irradiated EPDM and composites were investigated by the means of thermal analysis to verify if the presence of POSS molecules is able to reduce the oxidation level of free radicals generated during the degradation and to evaluate the effects of the irradiation. EPDM composites at 1, 3 and 5 mass% of POSS were thus degraded in a thermogravimetric (TG) balance in dynamic heating conditions (25–700 °C), in both inert and oxidative atmosphere by flowing nitrogen and air respectively. Thermal characterization was then completed by carrying out Differential Scanning Calorimetry (DSC) analysis from sub-ambient to better highlight the melting of the polymer and polymer composites occurring just above the room temperature. FTIR spectroscopy was also performed for the prepared samples to check the presence of the molecular filler in the composites and for the TG’s residue at 700 °C, in order to evaluate its nature. DSC and TGA parameters were detected and discussed to have information about the effect of the degradation’s environment, the effect of irradiation on polymer stabilization and the effect of POSS content in the polymer matrix.

Synthesis and properties of phthalonitrile-based resins containing spirocycle acetal

2020 ◽  
pp. 095400832097759
Author(s):  
Ke Li ◽  
Hua Yin ◽  
Kun Yang ◽  
Pei Dai ◽  
Ling Han ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Room Temperature ◽  
Laser Desorption Ionization ◽  
Scanning Calorimetry ◽  
Rheological Analysis ◽  
Ionization Time ◽  
Dynamic Mechanical ◽  
Nmr Spectrometry ◽  
Current Context

Designing novel low-melting, high-rigidity phthalonitrile resin is of great significance in the current context of development. In this study, rigid spirocycle acetal structure was introduced into phthalonitrile to reduce the melting point and maintain their thermal stability. The chemical structure of resins was confirmed by nuclear magnetic resonance (NMR) spectrometry, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and Fourier-transform infrared (FTIR) spectroscopy. The curing behaviors were studied by differential scanning calorimetry (DSC). Thermal stability and mechanical properties of the cured resins were investigated by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The processability was studied by rheological analysis. The results indicated the three monomers had a low melting temperature, wide processing windows and low viscosities. These polymers did not exhibit Tg from room temperature to 400°C, exhibited superb dynamic mechanical property and thermal stability.

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