scholarly journals Two-Step Finite Element Model Tuning Strategy of a Bridge Subjected to Mining-Triggered Tremors of Various Intensities Based on Experimental Modal Identification

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2062
Author(s):  
Paweł Boroń ◽  
Joanna Maria Dulińska ◽  
Dorota Jasińska
Keyword(s):  
Finite Element ◽  
Coulomb Friction ◽  
High Energy ◽  
Low Energy ◽  
Modal Identification ◽  
Dynamic Responses ◽  
Fe Model ◽  
Model Tuning ◽  
Tuning Strategy ◽  
Regularized Model

In this paper, a two-step tuning strategy of a finite element (FE) model of a bridge with pot bearings exposed to mining-triggered tremors of various intensities is proposed. In the study, a reinforced concrete bridge 160 m long is considered. Once the modal identification of the bridge was experimentally carried out based on low-energy ambient vibrations, the FE model was tuned by replacing the free-bearing sliding with a Coulomb friction-regularized model. This model of friction split the tangential relative displacement rates between contacting surfaces into a reversible elastic part and irreversible sliding. The elastic microslip (spring-like behavior) prior to macrosliding can be explained by the deformation of asperities (roughness of contacting surfaces on the microscopic scale). The proposed model allows for accurate sliding bearing performance simulation under both low-energy and high-energy mining-induced tremors. In the first step of the FE model tuning strategy, the elastic microslip constant was experimentally estimated based on the modal identification. In the second step, the macro-sliding friction parameter was implemented to address the realistic behavior of the bridge under mining-induced shocks. Finally, the dynamic responses of the bridge to mining-triggered tremors of various intensities were calculated and assessed using the untuned and tuned FE models. The analysis proved that the untuned model was not suitable for dynamic bridge assessment in the case of low-intensity tremors. The stresses obtained for this model turned out to be strongly underestimated. For shocks of higher intensity, frictionless sliding at the bearings gives a relatively good global estimation of the structure performance but undervalues its local response. The analysis also reveals that the tuned Coulomb friction-regularized model allows for the accurate simulation of sliding bearings under both low and high-energy mining-induced tremors.

scholarly journals Comparative analysis of linear dynamic responses and undamped systems of soil-pile-footing interaction for various soil media

2021 ◽  
Vol 8 (1) ◽  
pp. 082-097
Author(s):  
Meghna Pathak ◽  
Ravindra Pathak ◽  
Jagdish Narayan Vyas
Keyword(s):  
Finite Element ◽  
Axial Load ◽  
Dynamic Responses ◽  
Base System ◽  
Fe Model ◽  
Rational Analysis ◽  
Fixed Base ◽  
Soil Media ◽  
Recent Earthquakes ◽  
Damped Systems

It is seen from recent earthquakes that in case of fixed-base foundation system, damped systems have proved to be longing the lifespan of the structure by lengthening the lateral fundamental period that leads to higher damping in comparison to the assumptions of a fixed-base system. In this study, to better understand the phenomenon involved in soil-pile interaction a finite element simulation model is developed in Abaqus FEA software. The numerical model made for transient analysis follows Rayleigh's Damping Coefficient model for material damping. In this paper, a rational analysis of Dynamic Response of a Short-Bored Pile is made subject to axial load by the Finite Element Method. The analysis is performed using finite element Abaqus CAE software. The Soil media is developed for sand soil and clay soil with pile material as Mild Steel and RCC, and analysis is made for the combination of each material group with the incremental axial load. The same FE model is studied for damped material used in piles which results in a drastic change in displacement pattern.

scholarly journals Modeling and Comparative Analysis of Different Generic Cross Section B-Pillar Design in Roof Crush Impact

2021 ◽  
pp. 187-200
Author(s):  
Pankaj Kumar Jha ◽  
Rachayya Arakerimath
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Cross Section ◽  
Cross Sections ◽  
High Energy ◽  
Fe Model ◽  
Performance Study ◽  
Element Analysis ◽  
Pillar Design ◽  
Static Test

When a vehicle tips over onto its roof or side due to internal or external force on a vehicle is called Rollover impact. Rollover is a very critical impact compared to another mode of vehicle impacts. B-pillar and its cross-section design are very critical in the rollover impacts by reducing the cabin intrusion of vehicle. B-pillar absorbs most of the energy at the time of rollover and reduces the fatality rate of the passenger. In this work, a B-pillar finite element (FE) model is modeled to analyze as per FMVSS216a standard protocol to check the critical performance. Two generic cross-sections of the B-pillar are considered for preliminary assessment. This B-pillar designs FE model (cut model) are modeled and analyzed for FMVSS216a using LS-DYNA explicit code. The FMVS216a lab test is a quasi-static test and LS-DYNA is the well-accepted FEA tool to simulate the quasi-static test. LS-DYNA software is widely accepted as a multi-purpose finite element analysis (FEA), capable of solving complex problems in the field of Automobile, Aerospace, etc. So LS-DYNA is considered for the study of the B-Pillar simulations. Both the B-pillar designs are accessed and compared with respect to energy absorption, crush resistance characteristics with respect to the full vehicle rollover test. With the detailed performance study of both cross-section designs under rollover impact, the best performing B-pillar design in terms of high energy absorption and high vehicle resistance is selected for furtheroptimization study to meet the Roof crush standard requirements.

Aerodynamic Analysis in Time Domain of a Cable-Stayed Bridge

2012 ◽  
Vol 479-481 ◽  
pp. 1205-1208
Author(s):  
Chern Hwa Chen ◽  
Yuh Yi Lin ◽  
Cheng Hsin Chang ◽  
Shun Chin Yang ◽  
Yung Chang Cheng ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Time Domain ◽  
Field Tests ◽  
Element Model ◽  
Modal Identification ◽  
Dynamic Responses ◽  
Cable Stayed Bridge ◽  
The Time Domain ◽  
Frequency Domain Approach

To determine its actual dynamic responses under the wind loads, modal identification from the field tests was carried out for the Kao Ping Hsi cable-stayed bridge in southern Taiwan. The rational finite element model has been established for the bridge. With the refined finite element model, a nonlinear analysis in time domain is employed to determine the buffeting response of the bridge. Through validation of the results against those obtained by the frequency domain approach, it is confirmed that the time domain approach adopted herein is applicable for the buffeting analysis of cable-stayed bridges.

scholarly journals A Comparative Study of Analytical Rosenthal, Finite Element, and Experimental Approaches in Laser Welding of AA5456 Alloy

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 436 ◽  
Author(s):  
Hamidreza Hekmatjou ◽  
Zhi Zeng ◽  
Jiajia Shen ◽  
J. P. Oliveira ◽  
Homam Naffakh-Moosavy
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Laser Welding ◽  
High Energy ◽  
Experimental Results ◽  
High Energy Density ◽  
Analytical Equation ◽  
Fe Model ◽  
Melt Pool ◽  
Analytical Approaches

The thermal regime and microstructural phenomenon are studied by using finite-element (FE) modelling and the analytical Rosenthal equation during laser welding of aluminum alloy 5456 (AA5456) components. A major goal is to determine the merits and demerits of this analytical equation which can be an alternative to FE analysis, and to evaluate the effect of imperative assumptions on predicted consequences. Using results from the analytical and numerical approaches in conjunction with experiments, different physical features are compared. In this study, the results obtained from experiments in terms of melt pool shapes are compared with the predicted ones achieved from the numerical and analytical approaches in which the FE model is more accurate than the Rosenthal equation in the estimation of the melt pool dimensions. Furthermore, as to the partially melted zones, the estimations achieved from the numerical modeling are more genuine than ones from the analytical equation with regards to the experimental results. At high energy density, near keyhole welding mode, the reported results show that experimental melt widths are supposed to be narrower than the fusion widths estimated by the analytical solution. The primary explanation could be the influence of thermal losses that occurred during convection and radiation, which are neglected in the Rosenthal equation. Additionally, the primary dendrite arm spacing (PDAS) estimated with the numerical modeling and the analytical Rosenthal solution is comparable with the experimental results obtained.

EXPERIMENTAL MODAL TEST AND TIME-DOMAIN AERODYNAMIC ANALYSIS OF A CABLE-STAYED BRIDGE

2011 ◽  
Vol 11 (01) ◽  
pp. 101-125 ◽  
Author(s):  
C. H. CHEN ◽  
C. I. OU
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Time Domain ◽  
Field Tests ◽  
Element Model ◽  
Modal Identification ◽  
Dynamic Responses ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
The Time Domain

To determine its actual dynamic responses under the wind loads, modal identification from the field tests was carried out for the Kao Ping Hsi cable-stayed bridge in southern Taiwan. The dynamic characteristics of the bridge identified by a continuous wavelet transform algorithm are compared with those obtained by the finite element analysis. The finite element model was then modified and refined based on the field test results. The results obtained from the updated finite element model were shown to agree well with the field identified results for the first few modes in the vertical, transverse, and torsional directions. This has the indication that a rational finite element model has been established for the bridge. With the refined finite element model, a nonlinear analysis in time domain is employed to determine the buffeting response of the bridge. Through validation of the results against those obtained by the frequency domain approach, it is confirmed that the time domain approach adopted herein is applicable for the buffeting analysis of cable-stayed bridges.

scholarly journals Development of Composite Propeller Blade Model for High Velocity Impacts on Aircraft Fuselage using Finite Element Analysis

2019 ◽  
Vol 304 ◽  
pp. 01008
Author(s):  
Vasilis Votsios ◽  
Esteban Martino-Gonzalez ◽  
Jorge Lopez-Puente
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
High Energy ◽  
Fe Model ◽  
Propeller Blade ◽  
Minimum Thickness ◽  
Dynamic Simulations ◽  
Element Analysis ◽  
Aircraft Fuselage ◽  
Open Rotor

An open rotor blade failure and release event can result in a high energy impact on an aircraft fuselage that can reduce the strength of the structure and challenge the safe continuation of the flight and landing. This work highlights the development of a numerical approach and methodology in order to improve the assessment of the damage predictions of a composite propeller blade impact against the fuselage of an aircraft to be able to estimate a minimum thickness of shielding for the full protection of the airframe. A number of dynamic simulations were carried out, from rigid up to deformable and frangible projectiles at different angles of incidence, varying the material and the thicknesses using Abaqus/Explicit. The finite element (FE) models for blade and target were calibrated and validated separately allowing to capture the right behavior and failure modes. Impact tests of partial blade fragments against stiffened composite panels were correlated with simulations and the obtained results show a good agreement regarding deformations and delaminated area. Finally, a full blade FE model was generated and used for the fuselage impact numerical analysis. This was done within the frame of the Open Rotor project funded by Clean Sky European research programme.

scholarly journals Dynamic response of a cable-stayed footbridge to high-energy mining tremors

2019 ◽  
Vol 106 ◽  
pp. 01022
Author(s):  
Izabela Drygała ◽  
Joanna M. Dulinska ◽  
Maria Anna Polak ◽  
Marek Wazowski
Keyword(s):  
Dynamic Response ◽  
High Energy ◽  
Mining Activity ◽  
Dynamic Responses ◽  
Fe Model ◽  
Coal Basin ◽  
Kinematic Excitation ◽  
Upper Silesian Coal Basin ◽  
Mining Tremors ◽  
Standard Software

In this work an analysis of the dynamic response of a cable-stayed footbridge to mining tremors typical for two main regions of mining activity in Poland, i.e. the Legnica-Glogow Copper District (LGCD) and the Upper Silesian Coal Basin (USCB) is presented. For analysis, a 3-D finite element (FE) model of the structure was created in the ABAQUS/Standard software program. As a final result, the dynamic responses of the footbridge to the typical mining tremors were delivered. For this stage, the numerical simulations were conducted with the non-uniform kinematic excitation as well as with the uniform kinematic excitation. Finally, the evaluation of two calculation approaches was also made for the studied structure.

Tire Transient Analysis with an Explicit Finite Element Program

1997 ◽  
Vol 25 (4) ◽  
pp. 230-244 ◽  
Author(s):  
B. G. Kao ◽  
M. Muthukrishnan
Keyword(s):  
Finite Element ◽  
Strain Energy Function ◽  
Constitutive Law ◽  
Dynamic Responses ◽  
Fe Model ◽  
Fe Method ◽  
Design Data ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Wheel Model

Abstract The Finite Element (FE) method has long been recognized as an effective analytical tool for tire design analysis. However, meaningful prediction of the tire dynamic characteristics, such as tire transient responses, was not feasible due to the limitations of the traditional commercial FE programs. The availability of the explicit FE programs has made such simulation one step closer to reality. In this paper LS-DYNA3D, an explicit FE program, is used to simulate a simple tire test, demonstrating that it is possible to predict the tire dynamic responses from the tire design data. Geometry, material properties of various components and the fiber reinforcement, layout, etc. of a commercial tire were used to create the tire FE model. Tire carcass composite properties were calculated from a strain energy function derived for the fiber-reinforced rubber. The Mooney constitutive law was adopted for the elastic properties of the rubbers. The tire model was coupled with a rigid wheel model and inflated to a specified inflation pressure. The tire-wheel model was then loaded against a rotating rigid cylinder with an attached semi-circular cleat. The calculated tire center reaction forces showed good correlation with laboratory measurements.

Dynamic response of soil–pile–structure system subjected to lateral spreading: shaking table test and parallel finite element simulation

2020 ◽  
Vol 57 (4) ◽  
pp. 497-517 ◽  
Author(s):  
Lei Su ◽  
Hua-Ping Wan ◽  
Shaghayegh Abtahi ◽  
Yong Li ◽  
Xian-Zhang Ling
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Shaking Table Test ◽  
Lateral Spreading ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Fe Model ◽  
System Parameters ◽  
Quay Wall ◽  
Parallel Finite Element

This paper investigates the dynamic response of soil–pile–structure interaction (SPSI) system behind a quay wall in liquefiable soil and laterally spreading ground through both large-scale shaking table test and parallel finite element (FE) simulation. A three-dimensional (3D) nonlinear FE model is developed to simulate the target SPSI system using the parallel modeling technique with high computational efficiency. This FE model of the SPSI system is validated by the shaking table test results. The validated FE model is firstly used to further explore the dynamic behavior of the SPSI system with details on the global responses of the SPSI system and the local responses. Secondly, the validated FE model is used for global sensitivity analysis (GSA) to fully assess the effects of uncertain parameters on the interested dynamic responses of the SPSI system. The experimental and numerical investigations show that liquefaction-induced lateral spreading significantly affects the movement of the clay crust at the landside and the internal forces in piles behind the quay wall. GSA results show that the relative importance of system parameters depends on the dynamic responses of interest, while the interaction effects among system parameters on dynamic responses are not evident.

BAT Model Lateral Parameters Characterization Using Finite Element Model

2003 ◽  
Vol 31 (4) ◽  
pp. 225-247 ◽  
Author(s):  
B. G. Kao ◽  
T. Warholic
Keyword(s):  
Finite Element ◽  
Fe Analysis ◽  
Dynamic Responses ◽  
Model Parameters ◽  
Fe Model ◽  
Vibration Modes ◽  
Lateral Vibration ◽  
Dynamic Simulations ◽  
Lateral Direction ◽  
Tire Dynamics

Abstract The bushing analogy tire (BAT) model has been shown to be capable of modeling tire dynamics in vehicle dynamic simulations. In a recent paper, the tire and vehicle data have been used to demonstrate that the BAT model yields reasonable predictions of the vehicle vertical suspension dynamic responses up to the tire 2nd vertical mode (∼90 Hz). This paper studies the modeling of the tire dynamics in the lateral direction as the next step toward completion of the BAT model as a consistent 3-dimensional tire dynamics model. Finite element (FE) analysis is an advanced analytical method for engineering analysis and has been accepted as the standard analytical tool for tires in the automotive industry. The tire data generated with FE models are also repeatable, without the data noise contained in physically measured laboratory tire data. FE models are also ideal for tire modeling studies because they enable the analysts to precisely control the modeling parameters. A tire FE model is, therefore, used here to generate the needed tire data, including mass, static forces and dynamic vibration modes for BAT model characterization. The BAT model parameters, including the tire lateral stiffnesses and the tire/wheel mass and inertia, are extracted from the FE analysis results. The analytically predicted lateral vibration modal frequencies of the BAT model are then compared with the corresponding lateral vibration modes of the same FE model. It is shown that the resulting BAT model is a good approximation for the FE model in the lateral direction up to the third lateral (including rotational) vibration mode (∼70 Hz).

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