scholarly journals A Nonlinear Mechanics Model of Zigzag Cellular Substrates for Stretchable Electronics

2020 ◽  
Vol 87 (6) ◽  
Author(s):  
Shiwei Zhao ◽  
Feng Zhu ◽  
Zhengang Yan ◽  
Daochun Li ◽  
Jinwu Xiang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Analytical Model ◽  
Strain Curve ◽  
Stretchable Electronics ◽  
Electronic Systems ◽  
Stress Strain Curve ◽  
Element Analysis ◽  
Natural Motion ◽  
Mechanics Model ◽  
Nonlinear Stress

Abstract The use of cellular elastomer substrates not only reduces its restriction on natural diffusion or convection of biofluids in the realm of stretchable electronics but also enhances the stretchability of the electronic systems. An analytical model of “zigzag” cellular substrates under finite deformation is established and validated in this paper. The deformed shape, nonlinear stress–strain curve, and Poisson’s ratio–strain curve of the cellular elastomer substrate calculated using the reported analytical model agree well with those from finite element analysis (FEA). Results show that lower restriction on the natural motion of human skin could be achieved by the proposed zigzag cellular substrates compared with the previously reported hexagonal cellular substrates, manifesting another leap toward mechanically “invisible” wearable, stretchable electronic systems.

Folding and Deployment of a New Thin-Walled Tube Flexible Hinge

2014 ◽  
Vol 635-637 ◽  
pp. 365-369 ◽  
Author(s):  
Hui Yang ◽  
Rong Qiang Liu ◽  
Hong Wei Guo ◽  
Jian Guo Tao
Keyword(s):  
Finite Element Analysis ◽  
Strain Curve ◽  
Tension Test ◽  
Slot Width ◽  
Stress Strain Curve ◽  
Element Analysis ◽  
Flexible Hinge ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Explicit Solver

A new thin-walled tube flexible hinge with six slots is proposed. The slot geometry is parameterized in terms of slot width, length and distance between two adjacent slots. The experiment for tension test of the thin-walled tube hinge with six-slots is conducted by INSTRON and the tensile stress-strain curve is measured. Finite element analysis to investigate the quasi-static folding and deployment of the new hinges by ABAQUS/Explicit solver are employed to perform a series of parameter studies for the slots longitude lengthl0, the slot widthwand the distancedbetween two adjacent slots.

A Probabilistic Methodology for Random Stress-Strain Curves

1991 ◽  
Author(s):  
H. R. Millwater ◽  
S. V. Harren ◽  
B. H. Thacker
Keyword(s):  
Finite Element Analysis ◽  
Numerical Evaluation ◽  
General Procedure ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Behavior ◽  
Engineering Parameters ◽  
Analysis System

Abstract This paper presents a methodology for analyzing structures with random stress-strain behavior. Uncertainties in the stress-strain curve of a structure are simulated by letting a small number of engineering parameters which describe the stress-strain curve be random. Certain constraints are imposed on the engineering parameters in order to have a physically realizable material. A general procedure to handle correlation among the stress-strain parameters has also been developed. This methodology has been integrated into the NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) probabilistic structural analysis system. With this system, probabilistic finite element analysis of structures with random stress-strain behavior can be analyzed in an accurate, automated fashion. An example problem is presented to demonstrate the capabilities of the code. The problem analyzed is that of a pressure vessel fabricated with a material exhibiting random stress-strain behavior.

Anisotropic Mechanics of Cellular Substrate Under Finite Deformation

2018 ◽  
Vol 85 (7) ◽  
Author(s):  
Feng Zhu ◽  
Hanbin Xiao ◽  
Yeguang Xue ◽  
Xue Feng ◽  
Yonggang Huang ◽  
...  
Keyword(s):  
Cell Walls ◽  
Constitutive Models ◽  
Applied Strain ◽  
Stretchable Electronics ◽  
Stress Strain ◽  
Element Analysis ◽  
Natural Motion ◽  
Nonlinear Stress ◽  
Comparison Of The Results ◽  
Nonlinear Elastic

The use of cellular substrates for stretchable electronics minimizes not only disruptions to the natural diffusive or convective flow of bio-fluids, but also the constraints on the natural motion of the skin. The existing analytic constitutive models for the equivalent medium of the cellular substrate under finite stretching are only applicable for stretching along the cell walls. This paper aims at establishing an analytic constitutive model for the anisotropic equivalent medium of the cellular substrate under finite stretching along any direction. The model gives the nonlinear stress–strain curves of the cellular substrate that agree very well with the finite element analysis (FEA) without any parameter fitting. For the applied strain <10%, the stress–strain curves are the same for different directions of stretching, but their differences become significant as the applied strain increases, displaying the deformation-induced anisotropy. Comparison of the results for linear and nonlinear elastic cell walls clearly suggests that the nonlinear stress–strain curves of the cellular substrate mainly result from the finite rotation of cell walls.

Constitutive modelling of the mechanical response of a polycaprolactone based polyurethane elastomer: Finite element analysis and experimental validation through a bulge test

2020 ◽  
pp. 030932472095833
Author(s):  
Nahuel Rull ◽  
Asanka Basnayake ◽  
Michael Heitzmann ◽  
Patricia M. Frontini
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Response ◽  
Strain Curve ◽  
Image Correlation ◽  
Bulge Test ◽  
Polyurethane Elastomer ◽  
Stress Strain ◽  
Element Analysis ◽  
Nonlinear Stress

The mechanical behaviour of a high performance polycaprolactone based polyurethane elastomer (PCL) up to large strain levels, cyclic loading and equibiaxial stress has been assessed. The PCL can be categorised as a rubber-like material, thus, showing nonlinear stress-strain behaviour. The materials elastic network is based on a high molecular weight PCL polyol which gives the material its elastomeric behaviour similar to polyurethanes. In this work, mechanical testing capturing the major features of the stress-strain curve under different loading conditions is performed. Both, uni-axial loading-unloading curves and bulge test are thoroughly studied through the addition of digital image correlation (DIC) to measure the strain field. Results show the presence of hysteresis and loading configuration dependence. Then, two well-known hyperelastic constitutive models, the Arruda-Boyce eight-chain and Bergström-Boyce, were fitted to the uni-axial monotonic and cyclic test data and compared to the bulge test experimental results through finite element analysis (FEA) in Abaqus.

scholarly journals Non-linear finite element analysis of a Ti6Al4V/Inconel 625 joint obtained by explosion welding for sub-sea applications

2021 ◽  
Vol 38 (1) ◽  
pp. 13-16
Author(s):  
Pasqualino Corigliano
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Curve ◽  
Explosion Welding ◽  
Inconel 625 ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Non Linear

Industries have shown interest in the use of dissimilar metals to make corrosion-resistant materials combined with good mechanical properties in marine environments. Explosive welding can be considered a good method for joining dissimilar materials to prevent galvanic corrosion. The aim of the present study was to simulate the non-linear behaviour of a Ti6Al4V/Inconel 625 welded joint obtained by explosion welding from the values of the tensile ultimate strength and yielding strength of the parent materials. The present study compared the stress-strain curve from tensile loading obtained by the non-linear finite element analysis with the experimental stress-strain curve of a bimetallic joint. The applied method provides useful information for the development of models and the prediction of the structural behaviour of Ti6Al4V/Inconel 625 explosive welded joints.

scholarly journals Study on forging process and die design of parking sensor shell

2018 ◽  
Vol 185 ◽  
pp. 00020
Author(s):  
Tung-Sheng Yang ◽  
Jhong -Yuan Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
Forging Process ◽  
The Finite Element Analysis ◽  
Forging Force

The process of precision forging has been developed recently because of its advantages of giving high production rates and improved strength. For complete filling up, predicting the power requirement and final shape are important features of the forging process. A finite element method is used to investigate the forging force, the final shape and the stress distribution of the parking sensor shell forging. The stress-strain curve of AL-6082 is obtained by the computerized screw universal testing machine. The friction factor between AL-6082 alloy and die material (SKD11) are determined by using ring compression test. Stress-strain curve and fiction factor are then applied to the finite element analysis of the parking sensor shell forging. Maximum forging load, effective stress distribution and shape dimensions are determined of the parking sensor shell forging, using the finite element analysis. Then the parking sensor shells are formed by the forging machine. Finally, the experimental data are compared with the results of the current simulation for the forging force and shape dimensions of the parking sensor shell.

Fatigue Analysis of Induction Hardened Pins

1993 ◽  
Author(s):  
Mark J. Lindner ◽  
Abdalla Elbella
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Curve ◽  
Inelastic Strain ◽  
Induction Hardening ◽  
Cyclic Stress ◽  
Strain Response ◽  
Stress Strain Curve ◽  
Element Analysis ◽  
Element Mesh

Abstract A generalized procedure was developed to predict fatigue failure in the design of induction hardened pins. Finite element analysis was used to determine the elastic and inelastic strain response at subsurface locations. The finite element mesh was arranged in a layered fashion in which each layer had a unique cyclic stress-strain curve. The procedure incorporated the effects of residual stresses due to induction hardening and used the strain-life approach to determine fatigue life and damage. The areas of predicted failure agreed with those observed in the field.

Numerical Study on the Mechanical Behavior of Aluminum Foam Material Using CT Image

2009 ◽  
Vol 79-82 ◽  
pp. 1297-1300 ◽  
Author(s):  
Hyup Jae Chung ◽  
Kyong Yop Rhee ◽  
Beom Suck Han ◽  
Yong Mun Ryu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Aluminum Foam ◽  
Three Dimensional ◽  
Strain Curve ◽  
Foam Material ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
X Ray

In this study, finite element analysis was made to predict the tensile and compressive behaviors of aluminum foam material. The predicted tensile and compressive behaviors were compared with those determined from the tensile and compressive tests. X-ray imaging technique was used to determine internal structure of aluminum foam material. That is, X-ray computed tomography (CT) was used to model the porosities of the material. Three-dimensional finite element modeling was made by stacking two-dimensional tomography of aluminum foam material determined from CT images. The stackings of CT images were processed by three-dimensional modeling program. The results showed that the tensile stress-strain curve predicted from the finite element analysis was similar to that determined by the experiment. The simulated compressive stress-strain curve also showed similar tendency with that of experiment up to about 0.4 strain but exhibited a different behavior from the experimental one after 0.4 strain. The discrepancy of compressive stress-strain curves in a high strain range was associated with the contact of aluminum foam walls broken by the large deformation.

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