scholarly journals Novel Method for Probabilistic Evaluation of the Post-Earthquake Functionality of a Bridge

2021 ◽  
Author(s):  
Vesna Terzic ◽  
William Pasco
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Residual Displacements ◽  
Traffic Capacity ◽  
Probabilistic Evaluation ◽  
Bridge Column ◽  
Novel Method ◽  
The Finite Element Model

While modern overpass bridges are safe against collapse, their functionality will likely be compromised in case of design-level or beyond design-level earthquake, which may generate excessive residual displacements of the bridge deck. Presently, there is no validated, quantitative approach for estimating the operational level of the bridge after an earthquake due to the difficulty of accurately simulating residual displacements. This research develops a novel method for probabilistic evaluation of the post-earthquake functionality state of the bridge; the approach is founded on an explicit evaluation of bridge residual displacements and associated traffic capacity by considering realistic traffic load scenarios. This research proposes a high-fidelity finite-element model for bridge columns, developed and calibrated using existing experimental data from the shake table tests of a full-scale bridge column. This finite-element model of the bridge column is further expanded to enable evaluation of the axial load-carrying capacity of damaged columns, which is critical for an accurate evaluation of the traffic capacity of the bridge. Existing experimental data from the crushing tests on the columns with earthquake-induced damage support this phase of the finite-element model development. To properly evaluate the bridge's post-earthquake functionality state, realistic traffic loadings representative of different bridge conditions (e.g., immediate access, emergency traffic only, closed) are applied in the proposed model following an earthquake simulation. The traffic loadings in the finite-element model consider the distribution of the vehicles on the bridge causing the largest forces in the bridge columns.

Biodynamics of Human Thorax With Body Armors Subject to Bullet Impact

2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Body Armor ◽  
Projectile Impact ◽  
Human Thorax ◽  
Trachea And Bronchi ◽  
Armor System ◽  
The Finite Element Model

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.

Stiffness Simulation Analysis of Rubber Bush Mountings Subjected to Tilting Deflection

2013 ◽  
Vol 765-767 ◽  
pp. 341-344
Author(s):  
Bai Qin ◽  
Chao Wu ◽  
Bo Zhang ◽  
Quan Fu Wang ◽  
Ya Juan Ji
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Simulation Model ◽  
Axial Length ◽  
Simulation Analysis ◽  
Element Model ◽  
Simulation Data ◽  
Model Based ◽  
The Finite Element Model

The finite element model of rubber bush mountings is built up. And the value of the reduced tilting stiffness is obtained directly by solving the model. The simulation data and the experimental data can be seen to agree very closely. This fully proves the reliability of the simulation model. Based on this simulation model, which has been parameterized, the influence of the axial length and inner and outer radii on the reduced tilting stiffness of rubber bush is studied by using the co-simulation of MATLAB and ANSYS.

A Human Finite Element Model for Human-Cushion Interface Pressure Research

2013 ◽  
Vol 291-294 ◽  
pp. 2715-2718
Author(s):  
Hao Chen ◽  
Fang Wang ◽  
Jian Guo Zhang ◽  
Yan Ping Guo ◽  
Hai Yan Song
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Biomechanical Analysis ◽  
Human Model ◽  
Interface Pressure ◽  
Hexahedral Elements ◽  
Mechanical Experiment ◽  
The Finite Element Model

The aim of the present work was to develop a lain-human finite element model for cushion design to prevent bedsore by performing biomechanical analysis on interface pressure. The geometric data of the human was obtained by laser scans. The finite element model was composed of solid hexahedral elements. The material of the bed cushions was obtained according to the mechanical experiment. The human model was validated by comparing the simulation result with the experimental data. The validated finite element model could be used to facilitate, accelerate and economize the process of design of cushion.

Harmonic Wave Propagation and Testing of a Piezoelectric Curvilinear Arc Driver

2005 ◽  
Author(s):  
P. Smithmaitrie ◽  
H. S. Tzou
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Wave Propagation ◽  
Finite Element Model ◽  
Conceptual Model ◽  
Harmonic Wave ◽  
Element Model ◽  
Governing Equations ◽  
Circular Arc ◽  
The Finite Element Model

A piezoelectric curvilinear driver designed for an ultrasonic curvilinear motor is presented in this study. The design of piezoelectric curvilinear arc driver is proposed. The system governing equations, vibration behavior and wave propagation are investigated. Then, a conceptual model of piezoelectric circular arc driver is built and tested to demonstrate that the design of the curvilinear arc motor is feasible. Fabrication of the piezoelectric circular arc driver and implementation are respectively discussed, followed by results of the finite element model, and testing of the conceptual model. The demonstrations show that the curvilinear arc motor performs as expected. The experimental data is compared with the finite element results showing that the operating frequency of the conceptual motor compares well with the finite element result.

A Novel Method for Determining the Stiffness of a Composite Structure Resulting from the Manufacturing Process Using a Discrete Mesoscopic Finite Element Model

2015 ◽  
Vol 651-653 ◽  
pp. 399-404
Author(s):  
Cynthia J. Mitchell ◽  
James A. Sherwood ◽  
Lisa M. Dangora ◽  
Jennifer L. Gorczyca
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Shell Elements ◽  
Forming Simulation ◽  
Beam Elements ◽  
Fiber Reinforcements ◽  
Novel Method ◽  
Shell Forming ◽  
The Finite Element Model

This paper presents a methodology for extending the use of the beam-shell forming model to predict the structural properties of the composite part. After the forming simulation has been performed, the material definition will be changed such that the beam elements will represent the fiber reinforcements and the shell elements will represent the resin. The methodology behind the entire approach will be demonstrated using a stitched uniaxial glass fabric. The methodology for characterizing the fabric behavior will be discussed. After the part has been formed, it will be infused with resin. The methodology for characterizing the composite behavior will be introduced. The finite element model will be compared with experimental data to validate the methodology.

scholarly journals Study on Fatigue Property of Cracked Steel Plate Strengthened by CFRP

2019 ◽  
Vol 275 ◽  
pp. 02014
Author(s):  
Xi-Zhi Wu ◽  
Wei-Kang Yang ◽  
Xian-Guo Zang
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Fatigue Life ◽  
Finite Element Model ◽  
Cohesive Zone Model ◽  
Steel Plate ◽  
Fatigue Property ◽  
Element Model ◽  
Zone Model ◽  
The Finite Element Model

This paper presents fatigue property of CFRP-strengthened cracked steel plate. Firstly, the finite element model of CFRP-strengthened cracked steel plate is established by using the cohesive zone model. With the finite element model, stress intensity factor of the crack-tipis calculated. Then, it gives the fatigue tests of cracked steel plate. According to the experimental data, the material constants C and n value sare obtained. The prediction fatigue life is calculated by the finite element model and Paris function and verified by the experimental data. The results show that the prediction fatigue life, calculated by the finite element model and the Paris formula, is consistent with the experimental fatigue life, which verifies the accuracy of our prediction model with finite element model and the Paris function.

scholarly journals Investigation of the Thickness Differential on the Formability of Aluminum Tailor Welded Blanks

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Plastic Strain ◽  
Finite Element Model ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
Dome Height ◽  
Tailor Welded Blanks ◽  
Simulation Results

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.

scholarly journals Sensitivity Analysis of the Influence of Structural Parameters on Dynamic Behaviour of Highly Redundant Cable-Stayed Bridges

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Structural Parameters ◽  
Element Model ◽  
Structural Behavior ◽  
Model Tuning ◽  
The Finite Element Model ◽  
Cable Stayed Bridges

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.

Risk-Controlled Wellbore Stability Criterion Based on Machine Learning Assisted Finite Element Model

2021 ◽  
Author(s):  
Hussain AlBahrani ◽  
Nobuo Morita
Keyword(s):  
Machine Learning ◽  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Stability Criterion ◽  
Element Model ◽  
Rock Failure ◽  
Wellbore Stability ◽  
Wellbore Instability ◽  
Conventional Methods

Abstract In many drilling scenarios that include deep wells and highly stressed environments, the mud weight required to completely prevent wellbore instability can be impractically high. In such cases, what is known as risk-controlled wellbore stability criterion is introduced. This criterion allows for a certain level of wellbore instability to take place. This means that the mud weight calculated using this criterion will only constrain wellbore instability to a certain manageable level, hence the name risk-controlled. Conventionally, the allowable level of wellbore instability in this type of models has always been based on the magnitude of the breakout angle. However, wellbore enlargements, as seen in calipers and image logs, can be highly irregular in terms of its distribution around the wellbore. This irregularity means that risk-controlling the wellbore instability through the breakout angle might not be always sufficient. Instead, the total volume of cavings is introduced as the risk control parameter for wellbore instability. Unlike the breakout angle, the total volume of cavings can be coupled with a suitable hydraulics model to determine the threshold of manageable instability. The expected total volume of cavings is determined using a machine learning (ML) assisted 3D elasto-plastic finite element model (FEM). The FEM works to model the interval of interest, which eventually provides a description of the stress distribution around the wellbore. The ML algorithm works to learn the patterns and limits of rock failure in a supervised training manner based on the wellbore enlargement seen in calipers and image logs from nearby offset wells. Combing the FEM output with the ML algorithm leads to an accurate prediction of shear failure zones. The model is able to predict both the radial and circumferential distribution of enlargements at any mud weight and stress regime, which leads to a determination of the expected total volume of cavings. The model implementation is first validated through experimental data. The experimental data is based on true-triaxial tests of bored core samples. Next, a full dataset from offset wells is used to populate and train the model. The trained model is then used to produce estimations of risk-controlled stability mud weights for different drilling scenarios. The model results are compared against those produced by conventional methods. Finally, both the FEM-ML model and the conventional methods results are compared against the drilling experience of the offset wells. This methodology provides a more comprehensive and new solution to risk controlling wellbore instability. It relies on a novel process which learns rock failure from calipers and image logs.

Dynamic Analysis of a Turbocharger Centrifugal Compressor Impeller

1991 ◽  
Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Centrifugal Compressor ◽  
Element Model ◽  
Simplified Model ◽  
Cyclic Symmetry ◽  
Compressor Impeller ◽  
Cyclic Symmetric ◽  
The Finite Element Model

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.

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