Methods for Shape Fitting in Morphing Compliant Mechanisms

2021 ◽  
Author(s):  
Alden Yellowhorse ◽  
Jelle Rommers ◽  
Ali Amoozandeh ◽  
Just L. Herder
Keyword(s):  
Finite Element ◽  
Compliant Mechanisms ◽  
Algebraic Method ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Shape Fitting ◽  
Finite Element Software ◽  
Shape Approximation ◽  
Beam Bending ◽  
Fitting In

Abstract While compact folding is desirable for applications such as deployable mechanisms, achieving this with compliant mechanisms can be challenging. One reason for this is that the relaxed and stressed states of the mechanism are known and the loads producing the transition are unknown. The relaxed state is determined by the desired, deployed state and the stressed geometry is determined by the storage space. Approaches for solving this problem often require significant software development or cannot address problems in three dimensions. To address this problem, this work describes a method for designing 3D compliant mechanisms that can fold compactly. If the stressed and relaxed geometry are specified, an algebraic method can be used to find loads which best approximate the desired geometry. A least-squares approach is used to minimize error. A simplification of this method in two dimensions is also described. To further enhance the accuracy of the shape approximation, a method for varying the beam bending stiffness is described. For comparison, an inverse finite-element solver was implemented and paired with an optimizer and used to solve the same problem. Both methods were used to design a compliant, compactly folding beam. These results were compared with results from a commercial, finite-element software package.

Application of 3D Traction Force Microscopy to Mechanotransduction of Cell Clusters

2011 ◽  
Vol 70 ◽  
pp. 21-27 ◽  
Author(s):  
Jacob Notbohm ◽  
Jin Hong Kim ◽  
Anand Asthagiri ◽  
Guruswami Ravichandran
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Traction Force ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Cell Contact ◽  
Traction Force Microscopy ◽  
Inhibition Of Proliferation ◽  
Force Microscopy ◽  
Cell Clusters

With increasing understanding of the important role mechanics plays in cell behavior, the experimental technique of traction force microscopy has grown in popularity over the past decade. While researchers have assumed that cells on a flat substrate apply tractions in only two dimensions, a finite element simulation is discussed here that demonstrates how cells apply tractions in all three dimensions. Three dimensional traction force microscopy is then used to experimentally confirm the finite element results. Finally, the implications that the traction distributions of cell clusters have on the study of inhibition of proliferation due to cell contact and scattering of cells in a cluster are discussed.

Circular-Hinge Line Element for Finite Element Analysis of Compliant Mechanisms

2005 ◽  
Vol 127 (4) ◽  
pp. 766-773 ◽  
Author(s):  
Nicolae Lobontiu ◽  
Ephrahim Garcia
Keyword(s):  
Finite Element ◽  
Line Element ◽  
Compliant Mechanisms ◽  
Rectangular Cross Section ◽  
Constant Width ◽  
Element Model ◽  
Element Analysis ◽  
Finite Element Software ◽  
Total Potential ◽  
Six Degree Of Freedom

A three-node six degree-of-freedom per-node line element that is sensitive to axial, bending, and torsional loading is introduced to model single-axis right circular hinges of constant width that are utilized in compliant mechanisms. The Timoshenko model is applied for bending because this particular configuration is virtually short, and provisions are taken that the element is shear-locking free. The Saint Venant theory, which includes warping, is utilized to model torsion of the variable rectangular cross-section circular hinge. The principle of minimum total potential energy is employed to formulate the elemental stiffness and mass matrices, as well as the elemental nodal vector. Static force deflection and modal simulation that are performed based on this finite element model produce results that are in agreement with simulation by commercially available finite element software. The three-node line element is also compared to an analytical model in terms of stiffness and the results are again concurring.

scholarly journals Development of User Element Routine (UEL) for Cell-Based Smoothed Finite Element Method (CSFEM) in Abaqus

2019 ◽  
Vol 17 (02) ◽  
pp. 1850128 ◽  
Author(s):  
Pramod Y. Kumbhar ◽  
A. Francis ◽  
N. Swaminathan ◽  
R. K. Annabattula ◽  
S. Natarajan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Salient Feature ◽  
Three Dimensions ◽  
Benchmark Problems ◽  
Element Analysis ◽  
Finite Element Software ◽  
Linear Elastostatics ◽  
Smoothed Finite Element Method ◽  
Element Method

In this paper, we discuss the implementation of a cell-based smoothed finite element method (CSFEM) within the commercial finite element software Abaqus. The salient feature of the CSFEM is that it does not require an explicit form of the derivative of the shape functions and there is no need for isoparametric mapping. This implementation is accomplished by employing the user element subroutine (UEL) feature in Abaqus. The details on the input data format together with the proposed user element subroutine, which forms the core of the finite element analysis are given. A few benchmark problems from linear elastostatics in both two and three dimensions are solved to validate the proposed implementation. The developed UELs and the associated input files can be downloaded from https://github.com/nsundar/SFEM_in_Abaqus .

A Meshfree B-Spline Finite Element Formulation for Unilateral Contact Problems

2011 ◽  
Author(s):  
Alex Grishin ◽  
Jami J. Shah
Keyword(s):  
Finite Element ◽  
Solution Structure ◽  
Contact Problems ◽  
Two Dimensions ◽  
Element Formulation ◽  
B Spline ◽  
Finite Element Software ◽  
Manual Intervention ◽  
Current State ◽  
Spline Finite Element

The integrated, accurate and robust analysis of unilateral structural contact problems at all scales is a prerequisite for a comprehensive CAE process which accommodates the design of assemblies. In addition, such an integration must reduce any manual intervention to a bare minimum. The current reliance on legacy mesh-based finite element software for such analysis instead leads to excessive manual mesh construction and modification. Although the adoption of a meshfree formulation would seem to hold the answer, the current state-of-the-art in node-based formulations suffers from a lack of stability and/or consistency for such applications. This investigation demonstrates that there exists a meshfree B-Spline formulation which is consistent, stable, and demonstrates accuracy comparable to that of mesh-based approaches for simple frictionless Hertzian problems in two dimensions. Together with the Solution Structure Method (SSM) of boundary condition enforcement, it is argued that this approach may provide a more robust finite element framework within existing CAE pipelines.

Basic on Ansys to Study Frame Beam Supported one on Beam and the other on Column

2011 ◽  
Vol 368-373 ◽  
pp. 901-905
Author(s):  
Feng Song ◽  
Shao Jie Wang
Keyword(s):  
Finite Element ◽  
The Other ◽  
Plate Surface ◽  
Great Contribution ◽  
Beam Position ◽  
Finite Element Software ◽  
General Rules ◽  
Beam Bending ◽  
Beam Damage ◽  
Dangerous Section

Using finite element software ANSYS to do quasi-static numerical analysis for frame beam which supportted both in beam and columns. Analysis of simulation comes to a dangerous section of the frame beam position, and comes to the general rules of beam damage. The results showed that: dangerous section in columns end, and the end of the main and secondary girder are more safer;Board has a great contribution to improve the bearing capacity, especially for Beam-column nodes,at the same time the steel of plate surface which in beam and plate bottom which in columns have a great contribution to improve the capacity of the beam bending.

Finite Element Analysis on the Redistribution of Reaction at Support

2014 ◽  
Vol 602-605 ◽  
pp. 761-764
Author(s):  
Mu Chen ◽  
Jiang Hong Xue ◽  
Neng Gan
Keyword(s):  
Finite Element ◽  
Railway Bridge ◽  
Element Analysis ◽  
Guangzhou City ◽  
Finite Element Software ◽  
Partial Load ◽  
Torsional Coupling ◽  
Practical Engineering ◽  
Beam Bending ◽  
Set Up

We use the finite element software Midas FEA to set up space entity model, and discuss various factors including the stiffness of bearing, counteracting force of adjacent beam, the influence of the stiffness of bridge pier on reaction at support. In the practical engineering. Coupling of shear lag, stiffness of beam, bending-torsional coupling and partial load can also affect the redistribution of reaction at support. Through the simulation of the finite element software, we check the support of a railway bridge in Guangzhou city. In the end we found that the stiffness of beam can make the middle support have a tendency to increase. If we take all the factors into account, the force of the middle support will be greater than on the both ends of bearing and the force on the both ends of bearing will be approximately equal.

Experimental Study and Numerical Analysis of CFRP Reinforced Beam Bending Performance

2012 ◽  
Vol 193-194 ◽  
pp. 1210-1215
Author(s):  
Bo Qian ◽  
Jian Zhong Xia ◽  
Xian Hao Shi ◽  
Xiao Dong Pan
Keyword(s):  
Finite Element ◽  
Concrete Beam ◽  
Fiber Reinforced Polymer ◽  
Bending Performance ◽  
Finite Element Software ◽  
Reinforced Polymer ◽  
Cfrp Plate ◽  
Before And After ◽  
Strain Relationship ◽  
Beam Bending

This paper describes both the development and the mechanism of carbon fiber-reinforced polymer (CFRP), through Abaqus finite element software simulations to complete before and after joining the CFRP plate bending performance in two cases of RC beams, as well as in the loads of the load-displacement relations and stress-strain relationship, through the control of different pre-split value of working conditions, and the comparison of the data of the actual concrete beam experimental results prove that the Abaqus finite element of the feasibility and effectiveness in CFRP research, provide a reference for the actual project.

Calculating Energy Release Rate as a Function of Crack Length Using a Multiple-Step Crack Closure Technique in Tire Finite Element Models

2018 ◽  
Vol 46 (3) ◽  
pp. 130-152
Author(s):  
Dennis S. Kelliher
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Crack Length ◽  
Energy Release ◽  
Crack Closure ◽  
Release Rate ◽  
Fatigue Behavior ◽  
Three Dimensions ◽  
Quantitative Prediction ◽  
Closure Technique

ABSTRACT When performing predictive durability analyses on tires using finite element methods, it is generally recognized that energy release rate (ERR) is the best measure by which to characterize the fatigue behavior of rubber. By addressing actual cracks in a simulation geometry, ERR provides a more appropriate durability criterion than the strain energy density (SED) of geometries without cracks. If determined as a function of crack length and loading history, and augmented with material crack growth properties, ERR allows for a quantitative prediction of fatigue life. Complications arise, however, from extra steps required to implement the calculation of ERR within the analysis process. This article presents an overview and some details of a method to perform such analyses. The method involves a preprocessing step that automates the creation of a ribbon crack within an axisymmetric-geometry finite element model at a predetermined location. After inflating and expanding to three dimensions to fully load the tire against a surface, full ribbon sections of the crack are then incrementally closed through multiple solution steps, finally achieving complete closure. A postprocessing step is developed to determine ERR as a function of crack length from this enforced crack closure technique. This includes an innovative approach to calculating ERR as the crack length approaches zero.

scholarly journals Data on Orientation to Happiness in Higher Education Institutions from Mexico and El Salvador

Data ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 27
Author(s):  
Domingo Villavicencio-Aguilar ◽  
Edgardo René Chacón-Andrade ◽  
Maria Fernanda Durón-Ramos
Keyword(s):  
Higher Education ◽  
El Salvador ◽  
Latin American ◽  
Higher Education Institutions ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Stepwise Multiple Regression ◽  
Teacher Student ◽  
And Gender ◽  
Student’S T

Happiness-oriented people are vital in every society; this is a construct formed by three different types of happiness: pleasure, meaning, and engagement, and it is considered as an indicator of mental health. This study aims to provide data on the levels of orientation to happiness in higher-education teachers and students. The present paper contains data about the perception of this positive aspect in two Latin American countries, Mexico and El Salvador. Structure instruments to measure the orientation to happiness were administrated to 397 teachers and 260 students. This data descriptor presents descriptive statistics (mean, standard deviation), internal consistency (Cronbach’s alpha), and differences (Student’s t-test) presented by country, population (teacher/student), and gender of their orientation to happiness and its three dimensions: meaning, pleasure, and engagement. Stepwise-multiple-regression-analysis results are also presented. Results indicated that participants from both countries reported medium–high levels of meaning and engagement happiness; teachers reported higher levels than those of students in these two dimensions. Happiness resulting from pleasure activities was the least reported in general. Males and females presented very similar levels of orientation to happiness. Only the population (teacher/student) showed a predictive relationship with orientation to happiness; however, the model explained a small portion of variance in this variable, which indicated that other factors are more critical when promoting orientation to happiness in higher-education institutions.

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