Analytical validation of an explicit finite element model of a rolling element bearing with a localised line spall

2018 ◽  
Vol 416 ◽  
pp. 94-110 ◽  
Author(s):  
Sarabjeet Singh ◽  
Carl Q. Howard ◽  
Colin H. Hansen ◽  
Uwe G. Köpke
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Rolling Element Bearing ◽  
Analytical Validation ◽  
Explicit Finite Element ◽  
Rolling Element ◽  
Element Bearing

Finite Element Modeling of Unidirectional Non-Crimp Fabric for Manufacturing of Composites with Embedded Cabling

2013 ◽  
Vol 554-557 ◽  
pp. 484-491 ◽  
Author(s):  
Alexander S. Petrov ◽  
James A. Sherwood ◽  
Konstantine A. Fetfatsidis ◽  
Cynthia J. Mitchell
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Explicit Finite Element ◽  
Shell Elements ◽  
Beam Elements ◽  
Hybrid Finite Element ◽  
International Benchmarking ◽  
Unidirectional Glass ◽  
Forming Simulations

A hybrid finite element discrete mesoscopic approach is used to model the forming of composite parts using a unidirectional glass prepreg non-crimp fabric (NCF). The tensile behavior of the fabric is represented using 1-D beam elements, and the shearing behavior is captured using 2-D shell elements into an ABAQUS/Explicit finite element model via a user-defined material subroutine. The forming of a hemisphere is simulated using a finite element model of the fabric, and the results are compared to a thermostamped part as a demonstration of the capabilities of the used methodology. Forming simulations using a double-dome geometry, which has been used in an international benchmarking program, were then performed with the validated finite element model to explore the ability of the unidirectional fabric to accommodate the presence of interlaminate cabling.

Verification of Predicted Knee Replacement Kinematics During Simulated Gait in the Kansas Knee Simulator

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Jason P. Halloran ◽  
Chadd W. Clary ◽  
Lorin P. Maletsky ◽  
Mark Taylor ◽  
Anthony J. Petrella ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Knee Replacement ◽  
Degrees Of Freedom ◽  
Computational Models ◽  
Evaluation Process ◽  
Element Model ◽  
Explicit Finite Element ◽  
Knee Simulator ◽  
Flexion Extension

Evaluating total knee replacement kinematics and contact pressure distributions is an important element of preclinical assessment of implant designs. Although physical testing is essential in the evaluation process, validated computational models can augment these experiments and efficiently evaluate perturbations of the design or surgical variables. The objective of the present study was to perform an initial kinematic verification of a dynamic finite element model of the Kansas knee simulator by comparing predicted tibio- and patellofemoral kinematics with experimental measurements during force-controlled gait simulation. A current semiconstrained, cruciate-retaining, fixed-bearing implant mounted in aluminum fixtures was utilized. An explicit finite element model of the simulator was developed from measured physical properties of the machine, and loading conditions were created from the measured experimental feedback data. The explicit finite element model allows both rigid body and fully deformable solutions to be chosen based on the application of interest. Six degrees-of-freedom kinematics were compared for both tibio- and patellofemoral joints during gait loading, with an average root mean square (rms) translational error of 1.1 mm and rotational rms error of 1.3 deg. Model sensitivity to interface friction and damping present in the experimental joints was also evaluated and served as a secondary goal of this paper. Modifying the metal-polyethylene coefficient of friction from 0.1 to 0.01 varied the patellar flexion-extension and tibiofemoral anterior-posterior predictions by 7 deg and 2 mm, respectively, while other kinematic outputs were largely insensitive.

Studies on the formation of discontinuous chips during rock cutting using an explicit finite element model

2013 ◽  
Vol 70 (1-4) ◽  
pp. 635-648 ◽  
Author(s):  
Pradeep L. Menezes ◽  
Michael R. Lovell ◽  
Ilya V. Avdeev ◽  
Jeen-Shang Lin ◽  
C. Fred Higgs
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Rock Cutting ◽  
Explicit Finite Element

Testing and Analysis Process of Earthquake Resistance Mainframe Computer Structure

2016 ◽  
Author(s):  
Budy Notohardjono ◽  
Richard Ecker ◽  
Shawn Canfield
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Time History ◽  
Element Model ◽  
Seismic Events ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Mainframe Computer ◽  
Computer Structure ◽  
The Finite Element Model

A mainframe computer’s structure consists of a frame or rack, drawers with central processor units, IO equipment, memory and other electronic equipment. The focus of this structural mechanical analysis and design is on the frame, earthquake stiffening brackets and tie-down methods. The primary function of the frame is to protect critical electronic equipment in two modes. The first mode is during shipping shock and vibration, which provides excitation primarily in the vertical direction. The second mode of protection is protecting the equipment during seismic events where horizontal vibration can be significant. Frame stiffening brackets and tie-downs are features added to mainframe systems that must meet earthquake resistance requirements. Designing to withstand seismic events requires significant analysis and test efforts since the functional performance of the system must be maintained during and after seismic events. The frame stiffening brackets and anchorage system must have adequate strength and stiffness to counteract earthquake-induced forces, thereby preventing human injury and potential system damage. The frame’s stiffening bracket and tie-down combination must ensure continued system operation by limiting overall displacement of the structure to acceptable levels, while not inducing undue stress to the critical electronic components. This paper discusses the process of finite element analysis and testing of a mainframe computer structure to develop a design that can withstand a severe earthquake test profile. Finite element analysis modeling tools such as ANSYS, a general-purpose finite element solver, was used to analyze the initial frame design CAD model. Both implicit and explicit finite element methods were used to analyze the mainframe subjected to uniaxial and triaxial earthquake test profiles. The seismic simulation tests involve extensive uniaxial and triaxial earthquake testing in both raised floor and non-raised floor environments at a test facility. Prior to this extensive final test, in-house tests were conducted along with modal analysis of the prototype frame hardware. These tests are used to refine the dynamic characteristics of the finite element model and to design the frame stiffening bracket and tie-down system. The purpose of the modeling and in-house testing is to have a verified finite element model of the server frame and components, which will then lead to successful, seismic system tests. During experimental verification, the dynamic responses were recorded and analyzed in both the time and frequency domains. The use of explicit finite element modeling, specifically LS-DYNA, extends the capability of implicit, linear modeling by allowing the incorporation of test data time history input and the experimentally derived damping ratio. When combined with the ability to model non-linear connections and material properties, this method provides better correlation to measured test results. In practice, the triaxial seismic time history was applied as input to the finite element model, which predicted regions of plastic strain and deformation. These results were used to iteratively simulate enhancements and successfully reduce structural failure in subsequent testing.

scholarly journals Development of Practical Finite Element Models for Collapse of Reinforced Concrete Structures and Experimental Validation

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Mario Bermejo ◽  
Anastasio P. Santos ◽  
José M. Goicolea
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Elements ◽  
Finite Element Model ◽  
Computational Cost ◽  
Concrete Structures ◽  
Element Model ◽  
Reinforced Concrete Structures ◽  
Finite Element Models ◽  
Explicit Finite Element

This paper describes two practical methodologies for modeling the collapse of reinforced concrete structures. They are validated with a real scale test of a two-floor structure which loses a bearing column. The objective is to achieve accurate simulations of collapse phenomena with moderate computational cost. Explicit finite element models are used with Lagrangian meshes, modeling concrete, and steel in a segregated manner. The first model uses 3D continuum finite elements for concrete and beams for steel bars, connected for displacement compatibility using a penalty method. The second model uses structural finite elements, shells for concrete, and beams for steel, connected in common nodes with an eccentricity formulation. Both are capable of simulating correctly the global behavior of the structural collapse. The continuum finite element model is more accurate for interpreting local failure but has an excessive computational cost for a complete building. The structural finite element model proposed has a moderate computational cost, yields sufficiently accurate results, and as a result is the recommended methodology.

Effects of missing fasteners on the mechanical behavior of double-lap, multi-row composite bolted joints

2018 ◽  
Vol 52 (28) ◽  
pp. 3919-3933
Author(s):  
Fujian Zhuang ◽  
Puhui Chen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Load Distribution ◽  
Mechanical Characteristics ◽  
Joint Stiffness ◽  
Element Model ◽  
Bolted Joints ◽  
Explicit Finite Element ◽  
Single Column ◽  
Failure Loads

This paper presents a numerical investigation into the effects of missing fasteners on the mechanical characteristics of double-lap, multi-row composite bolted joints. A highly efficient explicit finite element model, which was validated effective and accurate by experiments, was developed and employed to conduct the virtual tests. Single-column and multi-column joints with various positions of missing fastener were considered. It is shown that the removal of fasteners can reduce the joint stiffness significantly, especially in joints with fewer columns or missing fasteners in the outside rows. The removal of fasteners can also cause considerable reductions in both the initial significant failure loads and ultimate loads of multi-column joints, while in single-column joints only the initial significant failure loads are influenced. Considering the load distribution, it is suggested that bolts in the same column as or in the adjacent column to the missing fastener experience a notable growth in load. Meanwhile, if a bolt bears more loads in the pristine joint, the larger changes in stiffness, ultimate strength, and load distribution may be obtained when it is lost.

A Model for Orthogonal Machining of Metal Matrix Composite Using Finite Element Method

2004 ◽  
Author(s):  
Yao Peng Zhu ◽  
S. Kannan ◽  
H. A. Kishawy
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Aluminium Oxide ◽  
Particulate Composite ◽  
Element Model ◽  
Plastic Properties ◽  
Explicit Finite Element ◽  
Orthogonal Machining ◽  
Oxide Particles ◽  
Stress Profiles

In this paper, a thermo-elasto plastic finite element model for machining of aluminium based particulate composite is presented. The presented model accounted for the thermoelasto-plastic properties of the material under consideration and explicit finite element solution was used. The aluminium oxide particles were modeled as perfectly elastic and the shapes considered were irregular. The interface between the aluminium oxide particulate and aluminium matrix was incorporated in this model. The effective and the shear stress profiles on the aluminium oxide particles were analyzed. The simulation values of cutting and feed forces were compared with the experimental data and were found to be well within the limits of divergence, thus, validating the proposed finite element model.

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