Towards Dynamic Tolerance Analysis Using a Finite Element Formulation

2000 ◽  
Author(s):  
Otto Salomons ◽  
Elmer Arentsen ◽  
Ronald Aarts ◽  
Fred van Houten
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Behavior ◽  
Geometric Model ◽  
Tolerance Analysis ◽  
Element Model ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Large Numbers ◽  
Physical Effects

Abstract A theoretical framework is proposed by which the effect of tolerances can be analyzed. Especially it focuses on the influence of clearances on the dynamic behavior of mechanisms. As opposed to previous publications, where a bondgraph formulation was used, this paper uses a finite element formulation in order to simulate the dynamic behavior under the influence of tolerances and other physical effects. The finite element formulation that has been selected for this work has two major advantages when compared to a bondgraph formulation. The first important advantage is that the method is analytical to a great extent. As a result, no numerically derived derivatives will exist, hence not leading to numeric inaccuracies. The second advantage is that small numbers can be separated from large numbers allowing to separate tolerances from the nominal path, resulting in faster simulations. The paper describes how a geometric model, including its tolerances, can be transformed into a corresponding finite element model that on its part consists of submodels. Based on this model, simulations can be performed which can provide insight in the dynamic behavior of the mechanism. The paper details on how geometric tolerances (such as form, orientation, position as well as size and clearances), with the focus on clearances, can be accounted for in a finite element model.

ANSYS Analysis of Heat Model for the Electromagnetic Drying Cylinder

2012 ◽  
Vol 268-270 ◽  
pp. 916-920
Author(s):  
Zheng Shun Wang ◽  
Wen Jia Han
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Thermal Load ◽  
Geometric Model ◽  
Element Model ◽  
Actual Situation ◽  
Ansys Software ◽  
Software Applications ◽  
Ansys Analysis ◽  
Drying Cylinder

In this thesis, the process of electromagnetic drying cylinder was analyzed creating by the dryer finite element model using ANSYS. The conduction thermal analysis, the applied load and solved showed the results of three major components. Which create a finite element model of the process, mainly the preprocessor using ANSYS software to create or import geometric models from other software applications, and then add the material properties. The last of the geometric model meshing and solving process need to enter solvers according to the actual situation. The setting is applied to the thermal load and conditions. Then it is proceed to the finite element solution operator. It final usually the Post 1, or Post2 view results, and based on our experience to judge correctly

Dynamic Behavior of String Subjected to Travelling Mass

2019 ◽  
Author(s):  
Shakti P. Jena ◽  
S. Naresh Kumar ◽  
Hemanth Cheedella
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Green’S Function ◽  
Dynamic Behavior ◽  
Green's Function ◽  
Transverse Vibration ◽  
Element Model ◽  
Numerical Approach ◽  
Complete Analysis ◽  
Numerical Example

Abstract The present study is based on the transverse vibration analogy of a string subjected to a travelling mass. The string is considered to be fixed at their both ends. The responses of the string due to the dynamic behavior of the travelling mass are determined using a numerical approach i.e. Green’s function. A Finite Element Model (FEM) has been developed to authenticate the numerical approach. For the responses analysis of the string, numerical example has been illustrated to study the behavior of the string due to the travelling mass and to check the convergence of the two proposed analogies (Green’s function and FEM). The complete analysis has been performed at constant travelling speed and different masses. The two approaches converge well and the Green’s function methodology found to be suitable one.

Modeling of the Mechanical Properties of a Polymer-Metal Foam Interpenetrating Phase Composite

2014 ◽  
Author(s):  
Jiayun Gao ◽  
Nassif Rayess
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Aluminum Foam ◽  
Metal Foam ◽  
Geometric Model ◽  
Element Model ◽  
Load Direction ◽  
Qualitative And Quantitative ◽  
Polymer Metal ◽  
The Finite Element Model

An interpenetrating phase composite is made by injection molding thermoplastic polymers into the voids of open-cell aluminum foam. Two types of polypropylene and an acetyl were mechanically introduced into the open cells of a Duocel® aluminum foam. Prior experimental work revealed that the combination of the polymer and the metal foam yields a hybrid that is stiffer than the polymer alone but has a reduced tensile strength. A finite element model using a tetrakaidecahedral unit cell is used to model the metal foam ligaments with the polymer occupying the remaining space. The geometric model as well as the interface between the two materials were validated against the experimental results. The resulting conclusions are that the aluminum ligaments oriented along the load direction cause an increase in stiffness but ligaments oriented laterally cause stress concentration that yield lower strength. The finite element model is used to give both qualitative and quantitative explanations of the physics of the interrelations between the metal foam and the polymer.

Modelling of rotors with three-dimensional solid finite elements

2001 ◽  
Vol 36 (4) ◽  
pp. 359-371 ◽  
Author(s):  
A Nandi ◽  
S Neogy
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Cross Sections ◽  
Three Dimensional ◽  
Element Model ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Two Dimensional ◽  
Inertia Effects ◽  
Solid Finite Elements

A shaft is modelled using three-dimensional solid finite elements. The shear-deformation and rotary inertia effects are automatically included through the three-dimensional elasticity formulation. The formulation allows warping of plane cross-sections and takes care of gyroscopic effect. Unlike a beam element model, the present model allows the actual rotor geometry to be modelled. Shafts with complicated geometry can be modelled provided that the shaft cross-section has two axes of symmetry with equal or unequal second moment of areas. The acceleration of a point on the shaft is determined in inertial and rotating frames. It is found that the finite element formulation becomes much simpler in a rotating frame of reference that rotates about the centre-line of the bearings with an angular velocity equal to the shafts spin speed. The finite element formulation in the above frame is ideally suited to non-circular shafts with solid or hollow, prismatic or tapered sections and continuous or abrupt change in cross-sections. The shaft and the disc can be modelled using the same types of element and this makes it possible to take into account the flexibility of the disc. The formulation also allows edge cracks to be modelled. A two-dimensional model of shaft disc systems executing synchronous whirl on isotropic bearings is presented. The application of the two-dimensional formulation is limited but it reduces the number of degrees of freedom. The three-dimensional solid and two-dimensional plane stress finite element models are extensively validated using standard available results.

Analysis and Improvement for Structure of the Front Frame of XG958 Wheel Loader

2012 ◽  
Vol 220-223 ◽  
pp. 723-726
Author(s):  
Yan Bin Li ◽  
Chao Zhang ◽  
Chun Liu ◽  
Huan Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Local Structure ◽  
Geometric Model ◽  
Element Model ◽  
Wheel Loader ◽  
Operation Conditions

The geometric model of the loader frame is directly established by the Pro/E software and imported to ANSYS to create finite element model. By the overall analysis of the front frame in the typical operation conditions, the whole distributions of stress of the front frame of XG958 wheel loader were obtained. Then, base on the distribution of the stress, the local structure of XG958 wheel loader frame was improved and the result was validated.

Finite Element Analysis of Beams With Constrained Damping Treatment Modeled Via Fractional Derivatives

1997 ◽  
Vol 50 (11S) ◽  
pp. S216-S224 ◽  
Author(s):  
Luis E. Sua´rez ◽  
Arsalan Shokooh ◽  
Jose´ Arroyo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Single Layer ◽  
Element Model ◽  
Beam Element ◽  
Element Formulation ◽  
Beam Model ◽  
Element Analysis ◽  
Damping Material ◽  
Derivatives Of

This paper presents a finite element formulation for the modeling of beams and frames with artificial damping provided by means of a constrained single layer of damping material. The behavior of the damping material is described using the fractional derivative model of viscoelasticity. In this model, the first order derivatives of the strains in the constitutive equations of the viscoelastic materials are replaced by derivatives of order α < 1. The finite element model developed is a one-dimensional beam element with three degrees of freedom per node. The dynamic response is calculated with a procedure involving a transformation of the original equations of motion to the state space and its decoupling with the eigenvectors of a special eigenvalue problem. The accuracy of the modal properties obtained with the beam model is compared with those calculated from a more elaborate plane stress finite element model. It was found that the proposed beam element provides very accurate results and with much lower computational costs than the 2-D model.

An Efficient Three Nodded Finite Element Formulation for Free Vibration Analysis of Sandwich Arches with Graded Metallic Cellular Core

2020 ◽  
Vol 12 (06) ◽  
pp. 2050069
Author(s):  
Mohammad Amir ◽  
Mohammad Talha
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Finite Element Model ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Core Layer ◽  
Element Model ◽  
Element Formulation ◽  
Present Formulation ◽  
Porosity Coefficient

An efficient finite element model based on three nodded element has been developed for the vibration analysis of sandwich arches with graded metallic cellular (GMC) core. The present formulation is based on the higher-order shear deformation theory and orthogonal curvilinear coordinate axes. The arch consists of two isotropic face sheets and a GMC core layer. The internal pores in the core layer follow the different types of distributions. The material properties of the GMC core layer of the sandwich arches vary in the thickness direction as a function in terms of porosity coefficient and mass density. Three types of porosity distributions have been considered to accomplish the vibration responses of sandwich arches. The present formulation is validated with limited results available in the literature. Few new results are computed and the effects of different influencing parameters such as porosity coefficient [Formula: see text], porosity distribution type, the thickness-to-length ratio [Formula: see text], boundary conditions and opening angle [Formula: see text] on the free vibration characteristics of sandwich arches with the GMC core are observed. The present finite element model gives better convergence and more accurate results than a conventional two nodded element-based finite element model.

scholarly journals Modeling of Self-Vibratory Drilling Head-Spindle System for Predictions of Bearings Lifespan

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
F. Forestier ◽  
V. Gagnol ◽  
P. Ray ◽  
H. Paris
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Behavior ◽  
Potential Risk ◽  
Feed Rate ◽  
High Speed ◽  
Element Model ◽  
Experimental Measurements ◽  
Alternative Response ◽  
Tool Breakage

The machining of deep holes is limited due to inadequate chip evacuation, which induces tool breakage. To limit this drawback, retreat cycles and lubrication are used. An alternative response to the evacuation problem is based on high-speed vibratory drilling. A specific tool holder induces axial self-maintained vibration of the drill, which enables the chips to be split. The chips are thus of a small size and can be evacuated. To anticipate the potential risk of decreased spindle lifespan associated with these vibrations, a model of the behavior of the system (spindle—self-vibrating drilling head—tool) is elaborated. In order to assess the dynamic behavior of the system, this study develops a rotor-based finite element model, integrated with the modelling of component interfaces. The current results indicate that the simulations are consistent with the experimental measurements. The influence of spindle speed and feed rate on bearing lifespan is highlighted.

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