Deployable Euler Spiral Connectors

2021 ◽  
pp. 1-17
Author(s):  
Collin Ynchausti ◽  
Nathan Brown ◽  
Spencer P Magleby ◽  
Anton E. Bowden ◽  
Larry L Howell
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Compliant Mechanisms ◽  
Element Analysis ◽  
Spinal Implant ◽  
In Series ◽  
Euler Spiral ◽  
Analytic Models

Abstract Deployable Euler Spiral Connectors (DESCs) are introduced as compliant deployable flexures that can span gaps between segments in a mechanism and then lay flat when under strain in a stowed position. This paper presents models of Euler spiral beams combined in series and parallel that can be used to design compact compliant mechanisms. Constraints on the design of DESCs are also presented. Analytic models were compared to finite element analysis and experimental data. A spinal implant and a linear ratcheting system are presented as illustrative applications of DESCs.

Bistable Compliant Four-Bar Mechanisms With a Single Torsional Spring

2006 ◽  
Author(s):  
Adarsh Mavanthoor ◽  
Ashok Midha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanism Design ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Stored Energy ◽  
Element Analysis ◽  
Bistable Behavior ◽  
Torsional Spring ◽  
Bistable Mechanism

Significant reduction in cost and time of bistable mechanism design can be achieved by understanding their bistable behavior. This paper presents bistable compliant mechanisms whose pseudo-rigid-body models (PRBM) are four-bar mechanisms with a torsional spring. Stable and unstable equilibrium positions are calculated for such four-bar mechanisms, defining their bistable behavior for all possible permutations of torsional spring locations. Finite Element Analysis (FEA) and simulation is used to illustrate the bistable behavior of a compliant mechanism with a straight compliant member, using stored energy plots. These results, along with the four-bar and the compliant mechanism information, can then be used to design a bistable compliant mechanism to meet specified requirements.

Three Approaches for Managing Stiffness in Origami-Inspired Mechanisms

2018 ◽  
Author(s):  
Alden Yellowhorse ◽  
Larry L. Howell
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Engineering Applications ◽  
Element Analysis ◽  
Advantages And Disadvantages ◽  
Large Size ◽  
Selection For

Ensuring that deployable mechanisms are sufficiently rigid is a major challenge due to their large size relative to their mass. This paper examines three basic types of stiffener that can be applied to light, origami-inspired structures to manage their stiffness. These stiffeners are modeled analytically to enable prediction and optimization of their behavior. The results obtained from this analysis are compared to results from a finite-element analysis and experimental data. After verifying these models, the advantages and disadvantages of each stiffener type are considered. This comparison will facilitate stiffener selection for future engineering applications.

Validation of Nitinol SMA Characteristics Using Finite Element Analysis and Closed Form Solutions

2013 ◽  
Vol 856 ◽  
pp. 147-152
Author(s):  
S.H. Adarsh ◽  
U.S. Mallikarjun
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Closed Form ◽  
Closed Form Solution ◽  
Form Solution ◽  
Fe Analysis ◽  
Element Analysis ◽  
Complex Behaviour ◽  
Closed Form Solutions

Shape Memory Alloys (SMA) are promising materials for actuation in space applications, because of the relatively large deformations and forces that they offer. However, their complex behaviour and interaction of several physical domains (electrical, thermal and mechanical), the study of SMA behaviour is a challenging field. Present work aims at correlating the Finite Element (FE) analysis of SMA with closed form solutions and experimental data. Though sufficient literature is available on closed form solution of SMA, not much detail is available on the Finite element Analysis. In the present work an attempt is made for characterization of SMA through solving the governing equations by established closed form solution, and finally correlating FE results with these data. Extensive experiments were conducted on 0.3mm diameter NiTinol SMA wire at various temperatures and stress conditions and these results were compared with FE analysis conducted using MSC.Marc. A comparison of results from finite element analysis with the experimental data exhibits fairly good agreement.

Incorporation of Spinal Flexibility Measurements Into Finite Element Analysis

1990 ◽  
Vol 112 (4) ◽  
pp. 481-483 ◽  
Author(s):  
Mack G. Gardner-Morse ◽  
Jeffrey P. Laible ◽  
Ian A. F. Stokes
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stiffness Matrix ◽  
Beam Element ◽  
Technical Note ◽  
Element Analysis ◽  
Spinal Motion ◽  
Spinal Flexibility

This technical note demonstrates two methods of incorporating the experimental stiffness of spinal motion segments into a finite element analysis of the spine. The first method is to incorporate the experimental data directly as a stiffness matrix. The second method approximates the experimental data as a beam element.

Design, analysis and test of a novel cylinder-driven mode applied to microgripper

2021 ◽  
pp. 1-14
Author(s):  
Xiaodong Chen ◽  
ZM Xie ◽  
Huifeng Tan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compliant Mechanisms ◽  
Research Field ◽  
Driving Pressure ◽  
Maximum Output ◽  
Element Analysis ◽  
Output Displacement ◽  
Micro Parts ◽  
The Relationship

Abstract How to enlarge the output displacement is a key issue in the research field of microgrippers. It is difficult to further enlarge the output displacement for the traditional displacement transmission mechanism (DTM). In this research, a two-stage amplification cylinder-driven DTM based on the compliant mechanisms is designed to realize the displacement output expansion. The opening and closing of the clamping jaws is driven by the air cylinder to enlarge the output displacement of the microgripper. According to the analysis of statics model of the mechanism, the relationship between the output displacement of the microgripper and the driving pressure of the cylinder is established. The magnification of the microgripper is obtained using a dynamic model. Moreover, based on the finite element analysis, the mechanical structure parameters are optimized. The microgripper was fabricated by utilizing wire electro discharge machining (WEDM) technique, and then a series of experiments were carried out to obtain the relationship between the displacement and the driving pressure. It is found that the maximum output displacement measured is 1190.4μm under the pressure of 0-0.6 Mpa, corresponding to the magnification of 47.63. Compared with the results of finite element analysis and theoretical calculation, the test results have a discrepancy of 2.39% and 6.62%, respectively. The microgripper has successfully grasped a variety of micro-parts with irregular shapes, and parallel grasping can be achieved, demonstrating the potential application of this design in the field of micromanipulation.

scholarly journals Residual Stress Distribution in Feal Weld Overlay on Steel

1994 ◽  
Vol 364 ◽  
Author(s):  
X.-L. Wang ◽  
S. Spooner ◽  
C. R. Hubbard ◽  
P. J. Maziasz ◽  
G. M. Goodwin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Post Weld Heat Treatment ◽  
Residual Stress Distribution ◽  
Element Analysis ◽  
Weld Overlay

AbstractNeutron diffraction was used to measure the residual stress distribution in an FeAl weld overlay on steel. It was found that the residual stresses accumulated during welding were essentially removed by the post-weld heat treatment that was applied to the specimen; most residual stresses in the specimen developed during cooling following the post-weld heat treatment. The experimental data were compared with a plasto-elastic finite element analysis. While some disagreement exists in absolute strain values, there is satisfactory agreement in strain spatial distribution between the experimental data and the finite element analysis.

The Finite Element Analysis of Omni-Direction Side-Loading Forklift Truck Lifting System Based on COSMOSWorks

2012 ◽  
Vol 184-185 ◽  
pp. 534-537
Author(s):  
Jing Jing Zhou ◽  
Ai Dong Guo ◽  
Chun Hui Li ◽  
Zhen Jiang Lin ◽  
Tie Zhuang Wu
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Optimization ◽  
Experimental Measurements ◽  
Element Analysis ◽  
Forklift Truck ◽  
The Finite Element Analysis ◽  
Lifting System

By setting contact sets, achieved overall analysis results of the mechanical properties with omni-direction side-loading forklift truck lifting system based on COSMOSWorks. And made an experimental measurements to omni-direction side-loading forklift truck lifting system by electrometric methods. There was a good relevance between experimental data and calculation values, and the deviation was basically within the 10 percent allowed. Finally, in this way it verified the correctness and reliability of the finite element analysis by experimental measurements. Ensured the omni-direction side-loading forklift truck lifting system could be safe and efficient to work. And also it laid a foundation for subsequent structural optimization.

scholarly journals Temperature-Dependence of Rubber Hyperelasticity Based on the Eight-Chain Model

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 932 ◽  
Author(s):  
Xintao Fu ◽  
Zepeng Wang ◽  
Lianxiang Ma ◽  
Zhaoxuan Zou ◽  
Qingling Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Rubber ◽  
Temperature Dependence ◽  
Large Temperature ◽  
Chain Model ◽  
Element Analysis ◽  
Filled Rubber ◽  
Different Temperatures

Rubber-based materials are widely used in a variety of industrial applications. In these applications, rubber components withstand various loading conditions over a range of temperatures. It is of great significance to study the mechanical behavior of vulcanized rubber at different temperatures, especially in a range of high temperatures. The temperature dependence of the constitutive behavior of filled rubber is important for the performance of the rubber. However, only a few constitutive models have been reported that investigate the stress–temperature relationship. In this paper, based on an analysis of experimental data, the effects of temperature on the hyperelastic behaviors of both natural rubber and filled rubber, with different mass fractions of carbon black, were studied. The regulation of stress and strain of natural rubber and filled rubber with temperature was revealed. In addition, an eight-chain model that can reasonably characterize the experimental data at different temperatures was proved. An explicit temperature-dependent constitutive model was developed based on the Arruda-Boyce model to describe the stress–strain response of filled rubber in a relatively large temperature range. Meanwhile, it was proved that the model can predict the effect of temperature on the hyperelastic behavior of filled rubber. Finally, the improved Arruda-Boyce model was used to obtain the material parameters and was then successfully applied to finite element analysis (FEA), which showed that the model has high application value. In addition, the model had a simple form and could be conveniently applied in related performance test of actual production or finite element analysis.

Finite Element Calculation of Sintering Deformation Using Limited Experimental Data

2008 ◽  
Vol 606 ◽  
pp. 103-118 ◽  
Author(s):  
Jing Zhe Pan ◽  
Ruo Yu Huang
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Ceramic Powder ◽  
Material Model ◽  
Element Analysis ◽  
Ceramic Components ◽  
On Line ◽  
Element Method

Predicting the sintering deformation of ceramic powder compacts is very important to manufactures of ceramic components. In theory the finite element method can be used to calculate the sintering deformation. In practice the method has not been used very often by the industry for a very simple reason – it is more expensive to obtain the material data required in a finite element analysis than it is to develop a product through trial and error. A finite element analysis of sintering deformation requires the shear and bulk viscosities of the powder compact. The viscosities are strong functions of temperature, density and grain-size, all of which change dramatically in the sintering process. There are two ways to establish the dependence of the viscosities on the microstructure: (a) by using a material model and (b) by fitting the experimental data. The materials models differ from each other widely and it can be difficult to know which one to use. On the other hand, obtaining fitting functions is very time consuming. To overcome this difficulty, Pan and his co-workers developed a reduced finite element method (Kiani et. al. J. Eur. Ceram. Soc., 2007, 27, 2377-2383; Huang and Pan, J. Eur. Ceram. Soc., available on line, 2008) which does not require the viscosities; rather the densification data (density as function of time) is used to predict sintering deformation. This paper provides an overview of the reduced method and a series of case studies.

An Improved Method for Designing Flexure-Based Nonlinear Springs

2012 ◽  
Author(s):  
Qiaoling Meng ◽  
Giovanni Berselli ◽  
Rocco Vertechy ◽  
Vincenzo Parenti Castelli
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compliant Mechanisms ◽  
Empirical Equations ◽  
Element Analysis ◽  
Closed Form Solutions ◽  
Nonlinear Springs ◽  
Aspect Ratios ◽  
Analytical Relations ◽  
Flexural Hinges

Monolithic Flexure-based Compliant Mechanisms (MFCM) can functionally act as nonlinear springs by providing a desired load-displacement profile at one point on their structure. Once the MFCM topology is chosen, these particular springs can be conveniently synthesized by resorting to the well-known Pseudo-Rigid-Body approximation, whose accuracy strongly depends on the modeling precision of the flexures’ principal compliance. For various types of flexures, closed-form solutions have been proposed which express the compliance factors as functions of the flexure dimensions. Nonetheless, the reliability of these analytical relations is limited to slender, beam-like, hinges undergoing small deflections. In order to overcome such limitations, this paper provides empirical equations, derived from finite element analysis, that can be used for the optimal design of circular, elliptical, and corner-filleted flexural hinges with general aspect ratios on the basis of both principal compliance and maximum bearable stress. As a case study, a nonlinear spring conceived as a four-bar linkage MFCM is synthesized and simulated by means of finite element analysis. Numerical results confirm that the aforementioned empirical equations outperform their analytical counterparts when modeling thick cross-section hinges undergoing large deflections.

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