Nonlinear Analysis of Elastomeric Keyboard Domes

1989 ◽  
Vol 56 (4) ◽  
pp. 751-755 ◽  
Author(s):  
John H. Lau ◽  
Albert H. Jeans
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Deflection ◽  
The Finite Element Method ◽  
Closed Form Solutions ◽  
Nonlinear Responses ◽  
Calculated Load ◽  
Hyperelastic Model ◽  
Load Deflection Curve ◽  
Element Method

The large deflection of an elastomeric dome is studied using the finite element method. The material properties of the elastomer are described by a hyperelastic model in order to capture the strain energy stored in the dome during deformation. The nonlinear responses are determined by the modified Riks procedure, and the calculated load-deflection curve agrees well with experimental results. In addition, a pressurized thick-walled spherical hyperelastic shell is analyzed and the stress results obtained by the finite element method are in excellent agreement with the closed-form solutions. The results provide a better understanding of the mechanical behavior of elastomeric keyboard domes and demonstrate the feasibility of using the finite element method to design such structures.

The Nonlinear Dynamic Analysis of Shells of Revolution With Asymmetric Properties by the Finite Element Method

1975 ◽  
Vol 97 (3) ◽  
pp. 163-171 ◽  
Author(s):  
S. Klein
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Nonlinear Dynamic ◽  
Large Deflection ◽  
Nonlinear Dynamic Analysis ◽  
Flow Rule ◽  
The Finite Element Method ◽  
Difference Matrix ◽  
Elastic Plastic ◽  
Element Method

A large deflection elastic-plastic analysis for general structures by the finite element method is presented. A Von Mises yield condition, its associated flow rule, and isotropic hardening are assumed. Nonlinear forces, due to nonlinear strain-displacement relations, plastic strains, and thermal gradients are developed for static and dynamic analyses and specialized for shell of revolution finite elements with asymmetric properties. The nonlinear dynamic equations are converted to a linear finite difference matrix equation, based on a nonlinear form of the Newmark Beta time integration method. A computer program, SABOR/DRASTIC 6, is used to demonstrate static, dynamic, and dynamic buckling solutions containing large deflection elastic-plastic response of shells with asymmetric properties and loads.

scholarly journals NUMERICAL-EXPERIMENTAL EVALUATION OF A HYPERELASTIC POLYURETHANE ADHESIVE

10.6036/9783 ◽  
2021 ◽  
Vol 96 (3) ◽  
pp. 246-249
Author(s):  
ADI CORRALES MAGALLANES ◽  
LUIS DEL LLANO VIZCAYA ◽  
CELSO EDUARDO CRUZ GONZALEZ ◽  
VICENTE BRINGAS RICO ◽  
ALDO AUGUSTO LOPEZ MARTINEZ ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Critical Load ◽  
Stress Test ◽  
Experimental Tests ◽  
Stress Tests ◽  
The Finite Element Method ◽  
Yeoh Model ◽  
Hyperelastic Model ◽  
Element Method

This article presents the results of the experimental tests carried out on a polyurethane hyperelastic adhesive. The Mooney-Rivlin, Ogden and Yeoh models were analyzed between others, with different order and parameters using the finite element method and the Ansys V17.1 package, with the aim of evaluating the convergence of a general hyperelastic model, to subsequently manufacture specimens and perform experimental uniaxial stress tests. The information obtained from the tests was supplied to a curve fitting model for several hyperelastic models, seeking to obtain a correlation between these tests. New analyzes were performed with the finite element method with the materials considered and the curves adjusted. The results were studied and the numerical hyperelastic model closest to reality was selected, observing that the 1st order Yeoh model presented significant deviations between -30% to 60% in the experimental stiffness, the 3rd order Yeoh model presented deviations of -5% to -30%, while Ogden models of 1st and 3rd order presented deviations of -3.5% to 25% and -3% to 20%, before approaching the critical load, where the model of Ogden of 1st order presented a deviation of 0.66% and that of 3rd order of -3.59%. The 2 parameter Mooney-Rivlin model presents a deviation of 3.9% when it approaches the critical load, but values from -2.04% to 15% during the development of the stress test, so that model proved to be the most appropriate to analyze the material investigated in this work. Key Words: Hyperelastic material, Experimental Methods, Numerical Methods, FEA

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