Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

Finite Element Mesh Generator Applying Constraints’ Propagation and Isoparametric Mapping

1991 ◽  
Author(s):  
J. Rodriguez ◽  
M. Him
Keyword(s):  
Finite Element ◽  
Mesh Generation ◽  
Element Model ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Analysis ◽  
Element Mesh ◽  
Mesh Generator ◽  
Generation Algorithm ◽  
Essential Input

Abstract This paper presents a finite element mesh generation algorithm (PREPAT) designed to automatically discretize two-dimensional domains. The mesh generation algorithm is a mapping scheme which creates a uniform isoparametric FE model based on a pre-partitioned domain of the component. The proposed algorithm provides a faster and more accurate tool in the pre-processing phase of a Finite Element Analysis (FEA). A primary goal of the developed mesh generator is to create a finite element model requiring only essential input from the analyst. As a result, the generator code utilizes only a sketch, based on geometric primitives, and information relating to loading/boundary conditions. These conditions represents the constraints that are propagated throughout the model and the available finite elements are uniformly mapped in the resulting sub-domains. Relative advantages and limitations of the mesh generator are discussed. Examples are presented to illustrate the accuracy, efficiency and applicability of PREPAT.

A Study Effect of Shooting 2 Balls in a Ball Swaging Process on Gram Load Parameter Using Finite Element Analysis

2014 ◽  
Vol 1061-1062 ◽  
pp. 421-426 ◽  
Author(s):  
Panupich Kheunkhieo ◽  
Kiatfa Tangchaichit
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Radial Direction ◽  
Base Plate ◽  
Element Model ◽  
Load Parameter ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Main Component

The purposes of this research are to explore the baseplate and actuator arm deformation which effect to the gram load which occur in the ball swaging process, the main component determining quality of assembly the head stack assembly with the actuator arm. By shooting a ball though the base plate, the component located on the head stack assembly, the base plate plastic deformation takes place and it in expand in radial direction. The base plate then adjoins with the actuator arm. Using the finite element method to reproduce the ball swaging process, we repeated to study effect of the swage press clamp and velocity. The study done by creating the three dimensionals finite element model to analyze and explain characteristics of the baseplate and actuator arm deformation which effect to gram load which effect to the ball swaging process.

An assessment of the Sachs method for measuring residual stresses in cold worked fastener holes

1998 ◽  
Vol 33 (4) ◽  
pp. 263-274 ◽  
Author(s):  
D J Smith ◽  
C G C Poussard ◽  
M J Pavier
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Cold Working ◽  
Element Model ◽  
Fe Model ◽  
Working Process ◽  
Element Analysis ◽  
Near Surface ◽  
Cold Worked ◽  
Good Agreement

Measurements of residual stresses in 6 mm thick aluminium alloy 2024 plates containing 4 per cent cold worked fastener are made using the Sachs method. The measurements are made on discs extracted from the plates. The measured tangential residual stress distribution adjacent to the hole edge are found to be affected by the disc diameter. The measured residual stresses are also in good agreement with averaged through-thickness predictions of residual stresses from an axisymmetric finite element (FE) model of the cold working process. A finite element analysis is also conducted to simulate disc extraction and then the Sachs method. The measured FE residual stresses from the Sachs simulation are found to be in good agreement with the averaged through-thickness predicted residual stresses. The Sachs simulation was not able to reproduce the detailed near-surface residual stresses found from the finite element model of the cold working process.

FINITE ELEMENT ANALYSIS OF A DEVICE FOR ALVEOLAR OSTEOGENIC DISTRACTION IN HUMAN MANDIBLE

2015 ◽  
Vol 27 (04) ◽  
pp. 1550034
Author(s):  
M. Cerrolaza ◽  
W. Carrero ◽  
J. Cedeño ◽  
L. Valencia
Keyword(s):  
Finite Element ◽  
Alveolar Bone ◽  
Involuntary Movement ◽  
Fem Analysis ◽  
Base Plate ◽  
Element Model ◽  
Critical Conditions ◽  
Element Analysis ◽  
Bone Deficiency ◽  
Bone Segment

Distractor devices are implanted temporarily in the bony structure in order to regenerate the bone tissue required and then be removed from the distraction site at the end of the consolidation period of callus. In this research, an osteogenic alveolar distractor (OAD) to deal with jaw bone deficiency in the alveolar area is proposed and described in this study. It addresses the FEM analysis of the proposed model of an OAD under physiological loading after the implantation. A finite element model subjected to physiological load exerted by the voluntary protrusion of the tongue on the alveolar distractor was analyzed and developed. The applied biological loads were the forces generated by the involuntary movement of the tongue against the distal end of the assembly. Both of them act on the head of the distractor screw, in the same direction but in opposite directions. The distraction device has been simulated on the alveolar bone, taking into account the most critical conditions that may occur during the distraction osteogenesis. The alveolar distractor proposed has a geometry that allows, by using only two intra-cortical screws, the attachment of the base plate to the alveolar bone without sacrificing a large periosteum area of the periosteum, which is primarily responsible for blood supply and nutrient source to the bone segment being distracted. The resulting stresses were lower than those corresponding to the resistance threshold in the bone.

scholarly journals Interfacial crack arrest in sandwich beams subjected to fatigue loading using a novel crack arresting device – Numerical modelling

2017 ◽  
Vol 21 (2) ◽  
pp. 422-438 ◽  
Author(s):  
G Martakos ◽  
JH Andreasen ◽  
C Berggreen ◽  
OT Thomsen
Keyword(s):  
Finite Element ◽  
Sandwich Beam ◽  
Interfacial Crack ◽  
Fatigue Loading ◽  
Element Model ◽  
Crack Arrest ◽  
Design Tool ◽  
Fe Model ◽  
Sandwich Beams ◽  
Element Analysis

A novel crack arresting device is implemented in foam-cored composite sandwich beams and tested using the Sandwich Tear Test (STT) configuration. A finite element model of the setup is developed, and the predictions are correlated with observations and results from a recently conducted experimental fatigue test study. Based on a linear elastic fracture mechanics approach, the developed FE model is utilised to simulate crack propagation and arrest in foam-cored sandwich beam specimens subjected to fatigue loading conditions. The effect of the crack arresters on the fatigue life is analysed, and the predictive results are subsequently compared with the observations from the previously conducted fatigue tests. The FE model predicts the energy release rate and the mode mixity based on the derived crack surface displacements, utilising algorithms for the prediction of accelerated fatigue crack growth as well as the strain field evolution in the vicinity of the crack tip on the surface of the sandwich specimens. It is further shown that the developed finite element analysis methodology can be used to gain a deeper insight onto the physics and behavioural characteristics of the novel peel stopper concept, as well as a design tool that can be used for the implementation of crack arresting devises in engineering applications of sandwich components and structures.

NONLINEAR FINITE ELEMENT ANALYSIS OF FRP STRENGTHENED RC BEAMS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Prabin Pathak ◽  
Y. X. Zhang
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Experimental Studies ◽  
Material Model ◽  
Element Model ◽  
Steel Reinforcement ◽  
Elastic Model ◽  
Fe Model ◽  
Rc Beams ◽  
Element Analysis

A simple, accurate and efficient finite element model is developed in ANSYS for numerical modelling of the nonlinear structural behavior of FRP strengthened RC beams under static loading in this paper. Geometric nonlinearity and material non-linear properties of concrete and steel rebar are accounted for this model. Concrete and steel reinforcement are modelled using Solid 65 element and Link 180 element, and FRP and adhesive are modelled using Shell 181element and Solid 45 element. Concrete is modelled using Nitereka and Neal’s model for compression, and isotropic and linear elastic model before cracking with strength gradually reducing to zero after cracking for tension. For steel reinforcement, the elastic perfectly plastic material model is used. FRPs are assumed to be linearly elastic until rupture and epoxy is assumed to be linearly elastic. The new FE model is validated by comparing the computed results with those obtained from experimental studies.

Simulation of the Transverse Fractures of the Sacrum Using a Finite Element Model of Lumbar Spine-Pelvis Segment

2008 ◽  
Author(s):  
A. Ivanov ◽  
A. Kiapour ◽  
N. Ebraheim ◽  
V. K. Goel
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Treatment Options ◽  
Element Model ◽  
Severe Trauma ◽  
Fe Model ◽  
Element Analysis ◽  
Modern Computer ◽  
Transverse Fractures

The sacrum fractures are very severe trauma which frequently accompanied with lumbar spine fractures. The surgical procedures often require primary stabilization of both lumbar spine and sacrum. To understand the rationale of the instrumentation numerous cadaveric studies were conducted to elucidate the anatomy of fractures and treatment options [1,2,3]. The modern computer technology allowed simulating the fractures and repairing using the Finite Element Analysis, also [4,5]. The last method has a raw of advantages versus cadaveric method such as higher reliability, accuracy, and safety. Finite element investigations of the pelvic fractures allowed comparing the influence of implants on pelvis stability. However, the extensive search of the literature failed to find a finite element model which includes the pelvis and lumbar spine together. Current study is the first step to accomplish this goal. An experimentally validated model of ligamentous lumbar spine was combined with the FE model of pelvis [7], and simulation of the sacrum fractures was conducted.

A Finite Element Analysis for Unbonded Flexible Risers Under Torsion

2007 ◽  
Author(s):  
A. Bahtui ◽  
H. Bahai ◽  
G. Alfano
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Model ◽  
Finite Element Model ◽  
Time Integration ◽  
Element Model ◽  
Integration Scheme ◽  
Element Analysis ◽  
Benchmark Solutions ◽  
The Finite Element Model

This paper presents a detailed finite element analysis of a five-layer unbonded flexible riser. The numerical results are compared analytical solutions for various load cases. In the finite element model all layers are modelled separately with contact interfaces placed between each layer. The finite element model includes the main features of the riser geometry with very little simplifying assumptions made. The numerical model was solved using a fully explicit time-integration scheme implemented in a parallel environment on a 16-processor cluster. The very good agreement found from numerical and analytical comparisons validates the use of our numerical model to provide benchmark solutions against which further detailed investigation will be made.

Finite-Element Model-Based Fault Prognosis on Key Components of the Reciprocating Compressor

2010 ◽  
Author(s):  
Wenqing Lu ◽  
Laibin Zhang ◽  
Wei Liang ◽  
Shuguo Li
Keyword(s):  
Finite Element ◽  
3D Model ◽  
Intrinsic Property ◽  
Element Model ◽  
Normal Operation ◽  
Fe Model ◽  
Reciprocating Compressor ◽  
Connecting Rod ◽  
Element Analysis ◽  
Fault Prognosis

The reciprocating compressor has become one of the most important equipments in petroleum and chemical industry. Study on vibration of the reciprocating compressor has a great significance to monitor the safety and reliability of the compressor. But it’s very difficult to predict the compressor and achieve the desired goal due to the complicated structure and operational aspect of the compressor. Experimental solution is expensive and time consuming. Therefore, finite element analysis (FEA) method is proposed to predict and locate the breakage of several key components on reciprocating compressor in compressor station. Non-destructive fault diagnosis and troubleshooting of the compressor can be achieved by application of FEA. The reasonable and simplified 3D model of the reciprocating compressor, which is validated with the actual prototype, is built by a CAD drawing software-SolidWorks. Then the ANSYS FE model is created by importing the 3D model into a FEA software-ANSYS. The ANSYS FE model can be used for stress analysis as well as intrinsic property analysis of the structural components. In this paper there are several ANSYS FE models of key components presented, including crankshaft, connecting-rod, crosshead and air valve. Then FEA method is applied to the fault localization of those components. According to the simulation results, the sites vulnerable to failure can be fixed on key components. The conclusions are consistent with the problems during the normal operation. Therefore, FEA is an effective and prospective method on fault prognosis of the reciprocating compressor.

Parametric Study of Swage Ball for Hard Disk Drive Swaging Process Using Finite Element Method

2013 ◽  
Vol 275-277 ◽  
pp. 2241-2247 ◽  
Author(s):  
Arbtip Dheeravongkit ◽  
Narongsak Tirasuntarakul
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
Base Plate ◽  
Disk Drive ◽  
Element Model ◽  
Complex Problem ◽  
Design Parameters ◽  
Element Analysis ◽  
Element Method

Ball swaging is a general method in head stack assembly process to permanently attach Head Gimbal Assemblies (HGA) on the actuator arm. In this process, the swage ball is guided by a pin through the inner base plate’s hole in order to deform the base plate to tightly attach to the actuator arm. However, the loosing problem can still be found quite often in the current swaging process. This research focuses on ball sizes and the number of balls used which currently no theoretical guidance in choosing the both parameters. Besides, the best combination of the both parameters can give the best swaging performance. The three-dimensional finite element model is created and analyzed to estimate the swaging performance according to the variation of both parameters by using the tightening torque and the fixing distance of base plate to determine the quality of the ball swaging process. The results from finite element method are treated as the sampling points which are used to create the interpolation in order to increase the considered cases to cover all happening cases from both parameters. After that, a searching algorithm is implemented to determine the most suitable ball size and the number of ball used for the process. By using the finite element analysis together with the interpolation and a searching algorithm, the optimal design parameters for a complex problem with multiple conditions of consideration can be easily found.

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