Finite Element Analysis of Load-Deflection and Creep Characteristics of Compressed Rubber Components for Vibration Control Devices

1996 ◽  
Vol 118 (3) ◽  
pp. 328-336 ◽  
Author(s):  
B. S. Lee ◽  
E. I. Rivin
Keyword(s):  
Finite Element ◽  
High Performance ◽  
Power Transmission ◽  
Cylindrical Shape ◽  
Element Analysis ◽  
Nonlinear Load ◽  
Rubber Blends ◽  
Creep Characteristics ◽  
Control Devices ◽  
Nonlinear Components

Elastomeric (rubber-like) materials are extensively used in various machine design applications, particularly for flexible elements of vibration/shock/noise control devices and of power transmission couplings. In order to have high performance characteristics, such elements should accommodate large static and dynamic loads and/or large deflections in a limited size. In many applications high damping, low creep and substantial nonlinearity of the load-deflection characteristic are required. These contradictory requirements are often impossible to satisfy just by selecting special rubber blends. It was demonstrated in [9] that for unbonded rubber flexible elements of a cylindrical shape loaded in a radial direction, desirable nonlinear load-deflection characteristics can be naturally obtained, and creep rate can be significantly reduced as compared with conventional shapes of bonded rubber elements loaded in compression. This paper presents the second part of the study [9]. It applies the Finite Element Method to analyze large deformations of nonlinear components made of viscoelastic materials. Some convenient and efficient methods are proposed to determine material constants for the analytical study of static load-deflection characteristics and creep. These proposed methods result in good agreement between the numerical results and the experimental results in [9]

Experimental Study of Load-Deflection and Creep Characteristics of Compressed Rubber Components for Vibration Control Devices

1994 ◽  
Vol 116 (2) ◽  
pp. 539-549 ◽  
Author(s):  
E. I. Rivin ◽  
B. S. Lee
Keyword(s):  
Experimental Study ◽  
Creep Rate ◽  
High Performance ◽  
Power Transmission ◽  
Cylindrical Shape ◽  
Nonlinear Load ◽  
Test Technique ◽  
Rubber Blends ◽  
Control Devices ◽  
Shape Influence

Elastomeric (rubber-like) materials are extensively used in various machine design applications, especially for flexible elements of vibration/shock/noise control devices and of power transmission couplings. In order to have high performance characteristics, such elements should accommodate large static and dynamic loads and/or large deflections in a limited size. In many applications high damping, low creep and substantial nonlinearity of the load-deflection characteristic are required. Since these specifications are contradictory, they are frequently impossible to satisfy just by selecting special rubber blends. The paper describes some results of an experimental study of geometric shape influence on the above specifications. It is demonstrated that for unbonded rubber flexible elements of a cylindrical shape loaded in a radial direction, a desirable nonlinear load-deflection characteristic can be naturally obtained (e.g., so-called “constant natural frequency” characteristic for vibration isolators), and creep rate can be significantly reduced as compared with conventional shapes of bonded rubber elements loaded in compression. This can lead to increased permissible deformations and/or loads on a flexible element, and/or to possibility of using rubber blends having higher damping (which is usually associated with higher creep rates). During the course of the research, an accelerated creep test technique has been developed which allows to use state-of-the-art servohydraulic testing machines for creep evaluation. It was also demonstrated that two definitions of the relative creep rate being used in the literature are not equivalent. More consistent results are obtained using the initial (free) height of the specimen (vs the deformation after 1 min of loading) as a reference dimension.

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

2020 ◽  
Vol 38 (1A) ◽  
pp. 25-32
Author(s):  
Waleed Kh. Jawad ◽  
Ali T. Ikal
Keyword(s):  
Finite Element ◽  
Effective Strain ◽  
Element Model ◽  
Cylindrical Shape ◽  
Element Analysis ◽  
Punch Force ◽  
Maximum Value ◽  
Element Simulation ◽  
Blank Sheet ◽  
The Finite Element Model

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by

Evaluation of Compressive Strengths of HPS Plate Systems Stiffened with Trapezoidal Stiffeners

2013 ◽  
Vol 671-674 ◽  
pp. 1025-1028
Author(s):  
Dong Ku Shin ◽  
Kyungsik Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Performance ◽  
Nonlinear Finite Element ◽  
Linear Strain ◽  
Element Analysis ◽  
Geometric Imperfections ◽  
Eurocode 3 ◽  
Initial Geometric Imperfections ◽  
Plate System

The ultimate compressive strengths of high performance steel (HPS) plate system stiffened longitudinally by closed stiffeners have been investigated by the nonlinear finite element analysis. Both conventional and high performance steels were considered in models following multi-linear strain hardening constitutive relationships. Initial geometric imperfections and residual stresses were also incorporated in the analysis. Numerical results have been compared to compressive strengths from Eurocode 3 EN 1993-1-5 and FHWA-TS-80-205. It has been found that although use of Eurocode 3 EN 1993-1-5 and FHWA-TS-80-205 may lead to highly conservative design strengths when very large column slenderness parameters are encountered

Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

2009 ◽  
Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Element Analysis ◽  
Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

Finite Element Modeling of Pad Deformation due to Diamond Disc Conditioning in Chemical Mechanical Polishing (CMP)

2012 ◽  
Author(s):  
Emmanuel A. Baisie ◽  
Z. C. Li ◽  
X. H. Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Material Removal ◽  
High Performance ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Element Analysis ◽  
Fea Model ◽  
Pad Wear ◽  
Diamond Disc

Chemical mechanical planarization (CMP) is widely used to planarize and smooth the surface of semiconductor wafers. In CMP, diamond disc conditioning is traditionally employed to restore pad planarity and surface asperity. Pad deformation which occurs during conditioning affects the material removal mechanism of CMP since pad shape, stress and strain are related to cut rate during conditioning, pad wear rate and wafer material removal rate (MRR) during polishing. Available reports concerning the effect of diamond disc conditioning on pad deformation are based on simplified models of the pad and do not consider its microstructure. In this study, a two-dimensional (2-D) finite element analysis (FEA) model is proposed to analyze the interaction between the diamond disc conditioner and the polishing pad. To enhance modeling fidelity, image processing is utilized to characterize the morphological and mechanical properties of the pad. An FEA model of the characterized pad is developed and utilized to study the effects of process parameters (conditioning pressure and pad stiffness) on pad deformation. The study reveals that understanding the morphological and mechanical properties of CMP pads is important to the design of high performance pads.

Finite Element Analysis of Circular Wedge Connections

2000 ◽  
Author(s):  
Christoph Grossmann ◽  
Oliver Tegel
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Analytic Function ◽  
Sliding Friction ◽  
Power Transmission ◽  
Structural Performance ◽  
Element Analysis ◽  
Coefficient Of Sliding Friction ◽  
The Finite Element Analysis

Abstract In this paper, the finite element analysis of circular wedge connections is described, and conclusions for the performance of the connection are derived. In the foreground of the examinations are stresses and deformations while tightening of the connection. Starting with the general structural performance, the influences on power transmission like slope, number of wedges, coefficient of sliding friction and outer hub diameter are discussed. An analytic function to describe the gap pressure within the tightened joint is introduced and rates to explain the problem of centering of circular wedge connections are shown. Finally two concepts for dimensioning are presented and recommendations for application of this connection are given.

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