scholarly journals Analysis of Equibiaxial Tension Tests for Hyperelastic EAP Film

Author(s):  
huaan luo ◽  
Yin-Long Zhu ◽  
Hai-Feng Zhao ◽  
Jing-Jing Zhang

Abstract Equibiaxial tension tests for hyperelastic electroactive polymers (EAPs) are important means to obtain the mechanical properties. There are three main methods: equibiaxial planar tension, radial tension and bulge test. The finite element analysis software is used to model and analyze the influence of testing apparatus, specimen geometric parameters on the test results and accuracy. The results show that the uniformity of the deformation of the square film can be effectively improved by using single corner point fixed tension in equibiaxial planar tension test, and the force error also decreased; the number of the cuts and the size of punched holes should be appropriate in radial tension test of circular diaphragm specimen to avoid the material strength failure caused by excessive tension along the edge of transition arc between grips and excessive deformation of tensile belt between the cuts; in bulge test, the sampled deformation data should be near the spherical pole to obtain more accurate stress-strain relationship owing to contour error and non-uniform deformation, a certain range of model parameters will limit the scope of simulation analysis. This paper proposed research provides guidance for the design of equibiaxial tension test apparatus and method to obtain more accurate test results.

2011 ◽  
Vol 243-249 ◽  
pp. 2726-2731 ◽  
Author(s):  
Xiang Yu Shang ◽  
Guo Qing Zhou

At-rest earth pressure codfficient,K0,is very important in geotechnical engineering design and finite element analysis. At present, it’s treated as a constant usually for given soil in FEM analysis. However recent test results indicate that K0of both clay and sand varies with pressure increasing nonlinearly. It’s shown that Duncan-Chang model, a kind of hypoelastic model widely used, can reproduce K0varying with pressure. The calculating procedure of K0derived from Duncan-Chang’s E-B model is proposed, and then influence of model parameters on calculated K0is explored. Studies show that cohesionless soil’s calculated K0decreases with pressure increasing, while cohesive soil’s calculated K0increases with pressure increasing. Three of the seven model parameters, m, Kband Rf, have a positive correlation with calculated K0, and there is a negative correlation between the residual parameters and calculated K0.The influence of seven model parameters on the calculated K0decreases gradually in the following order: m ,n, Rf, φ, c, K, Kb.


1991 ◽  
Vol 239 ◽  
Author(s):  
Martha K. Small ◽  
Joost J. Vlassak ◽  
William D. Nix

ABSTRACTSince its first application to thin films in the 1950's, the bulge test has had a prominent place in the field of thin film mechanical properties. The major appeal of the technique is that it is analogous to the familiar uniaxial tension test, which is commonly applied to bulk materials. At the same time, it avoids the sample tearing and alignment problems associated with micro-tensile tests. Unfortunately, bulge test results have been sometimes controversial and difficult to reproduce. In this paper we address possible causes for mese inconsistencies and describe a method by which the bulge test technique can be made to produce accurate and reliable results.


Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Hiroshi Yoshihara

Abstract In this research, Poisson's ratio of plywood as obtained by a tension test was examined by varying the width of the specimen. The tension tests were conducted on five-plywood of lauan (Shorea sp.) with various widths, and Young's moduli and Poisson's ratios of the specimens were measured. Finite element calculations were independently conducted. A comparison of the experimental results with those of finite element analysis revealed that Young's modulus could be obtained properly when the width of the plywood strip varied. In contrast, the width of the plywood strip should be large enough to determine Poisson's ratio properly.


2013 ◽  
Vol 446-447 ◽  
pp. 1425-1428
Author(s):  
Hong Ming Li ◽  
Jin Wu ◽  
Ying Jie Zhang

An efficient way to repair the damage of concrete is to enable the concrete adapt to the surrounding environment actively and have self-repair capabilities. In this paper, a type of concrete beam with embedded glass fibers filled with adhesive capable of crack self-repair was investigated. The capacity of self-repair cracks in concrete beams was verified by bending tests, and the influence of the layout of glass fibers on crack self-repair was studied. Test results show that the stiffness of concrete beams increases after crack repair. The glass fibers can be arranged according to the average crack spacing of reinforced concrete beams. In addition, the influence of the levels of crack repair on properties of concrete beams was analyzed with the finite element analysis software ANSYS.


2008 ◽  
Vol 35 (7) ◽  
pp. 751-755 ◽  
Author(s):  
M.R. Alam ◽  
A.S.J. Swamidas ◽  
J. Gale ◽  
K. Munaswamy

The experimental investigation described in this study was carried out to determine the physical and mechanical properties (elastic moduli, Poisson’s ratio, compressive and tensile strengths, hardness and plane strain fracture toughness) of slate quarried from Britannia Cove, Bonavista, Newfoundland, Canada. Microscopic observations were carried out to determine layers’ orientation and thickness and the grain boundaries. All tests were carried out according to American Society for Testing and Materials (ASTM) and International Society for Rock Mechanics (ISRM) procedures. The results obtained from this investigation were compared with those obtained from other published results for slate, mined from different parts of the world. It is seen that the present test results are compatible with other published results except for fracture toughness and direct tension tests. In fracture toughness tests, the calculated values using accepted empirical equations were much higher than the numerically computed values using finite element analysis (FEA). For the case of direct and indirect tension tests, the differences between our experimental values and previously published results were quite large.


2009 ◽  
Vol 37 (4) ◽  
pp. 226-253 ◽  
Author(s):  
M. Liu ◽  
M. S. Hoo Fatt

Abstract REFERENCE: Liu, M. and Hoo Fatt, M. S., "A Three-Dimensional Constitutive Model for the Dynamic Response of Rubber," Tire Science and Technology, TSTCA, Vol. 37, No. 4, October - December 2009, pp. 226-253. The development of a constitutive model to describe the dynamic response of a filled rubber compound is presented in this paper. A series of cyclic tension tests were done on the rubber compound with mean strains ranging from 0.2 to 0.5, strain amplitudes ranging from 0.05 to 0.2, and strain rates ranging from 0.1 to 10 s−1. The cyclic strain-controlled test results showed material rate dependence and hysteresis, and this motivated the development of a phenomenological-based, hyper-viscoelastic constitutive model. A Zener model, i.e., a spring in parallel with a Maxwell element, was assumed. The total stress was decomposed into a rate-independent equilibrium stress and a rate-dependent overstress. The springs were modeled as neo-Hookean, while the damper was defined by a nonlinear viscosity function. Material constants for the constitutive model were calculated from the cyclic tension test results. Cyclic tension tests were also performed on a sheet with central hole to check the accuracy of the constitutive model. The constitutive model was implemented into ABAQUS Standard with a user-defined material subroutine. The finite element analysis simulation of the rubber sheet with a central hole demonstrated relatively good agreement with the experimental data.


2019 ◽  
Vol 23 (02) ◽  
pp. 75-80
Author(s):  
Beate Schüßler ◽  
Andrea Pfingsten ◽  
Thomas Schöttker-Königer

ZusammenfassungZur Überprüfung der Nervenleitfähigkeit werden Kraft, Reflexe und Sensibilität getestet. Bei der Untersuchung der Mechanosensitivität eines Nervs kommen neurodynamische Tests zum Einsatz. Der Upper Limb Neural Tension Test (ULNT) 1 bestimmt die Mechanosensitivität des N. medianus.Ziel der Studie war die Untersuchung der Intertester-Reliabilität des ULNT 1 von nicht spezialisierten Physiotherapeuten bei Probanden mit unilateralen Nacken- und/oder Armsymptomen.Die Therapeuten beurteilten binär und metrisch die Kriterien patientenspezifische Symptome, strukturelle Differenzierung und Bewegungsausmaß sowie das Gesamtergebnis bei 33 Patienten mit unilateralen Nacken- und/oder Armsymptomen. Bei den binären Daten bestimmte der Fleiss-Kappa und bei den metrischen Daten der Intraklassen-Korrelationskoeffizient die Reliabilität. Die zusätzlich erstellten Regressionsmodelle sollten den Einfluss der einzelnen Beurteilungskriterien auf die Gesamtentscheidung herausfiltern.Mit Ausnahme der Reproduzierbarkeit patientenspezifischer Symptome scheint die Beurteilung des ULNT 1 durch nicht spezialisierte Therapeuten nur schlecht vergleichbar zu sein. Da die metrische Bewertungsweise die individuellen Schwellenwerte besser darstellt, ist diese der binären vorzuziehen.


2018 ◽  
Vol 46 (3) ◽  
pp. 174-219 ◽  
Author(s):  
Bin Li ◽  
Xiaobo Yang ◽  
James Yang ◽  
Yunqing Zhang ◽  
Zeyu Ma

ABSTRACT The tire model is essential for accurate and efficient vehicle dynamic simulation. In this article, an in-plane flexible ring tire model is proposed, in which the tire is composed of a rigid rim, a number of discretized lumped mass belt points, and numerous massless tread blocks attached on the belt. One set of tire model parameters is identified by approaching the predicted results with ADAMS® FTire virtual test results for one particular cleat test through the particle swarm method using MATLAB®. Based on the identified parameters, the tire model is further validated by comparing the predicted results with FTire for the static load-deflection tests and other cleat tests. Finally, several important aspects regarding the proposed model are discussed.


2012 ◽  
Vol 40 (1) ◽  
pp. 25-41 ◽  
Author(s):  
H. M. R. Aboutorabi ◽  
L. Kung

Abstract REFERENCE: H. M. R. Aboutorabi and L. Kung, “Application of Coupled Structural Acoustic Analysis and Sensitivity Calculations to a Tire Noise Problem,” Tire Science and Technology, TSTCA, Vol. 40, No. 1, January – March 2012, pp. 25–41. ABSTRACT: Tire qualification for an original equipment (OE) program consists of several rounds of submissions by the tire manufacturer for evaluation by the vehicle manufacturer. Tires are evaluated both subjectively, where the tire performance is rated by an expert driver, and objectively, where sensors and testing instruments are used to measure the tire performance. At the end of each round of testing the evaluation results are shared and requirements for performance improvement for the next round are communicated with the tire manufacturer. As building and testing is both expensive and time consuming predictive modeling and simulation analysis that can be applied to the performance of the tire is of great interest and value. This paper presents an application of finite element analysis (FEA) modeling along with experimental verification to solve tire noise objections at certain frequencies raised by an original equipment manufacturer (OEM) account. Coupled structural-acoustic analysis method was used to find modal characteristics of the tire at the objectionable frequencies. Sensitivity calculations were then carried out to evaluate the strength of contribution from each tire component to the identified modes. Based on these findings changes to the construction were proposed and implemented that addressed the noise issue.


2012 ◽  
Vol 487 ◽  
pp. 203-207
Author(s):  
Gong Xue Zhang ◽  
Xiao Kai Shen

Purpose, with the application of workbench finite element analysis software, get the analysis results of DVG 850 high-speed vertical machining center via the modal analysis and harmonic response analysis. Use the calculation results for reference, put forward the improved method, and prove the credibility of the simulation analysis by testing DVG 850 prototype.


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