A structural model of ultra-microelectrodes for shear-force based scanning electrochemical microscopy

2018 ◽  
Vol 29 (18) ◽  
pp. 3562-3571 ◽  
Author(s):  
Vijay Venkatesh ◽  
Robert Northcutt ◽  
Christian Heinemann ◽  
Vishnu Baba Sundaresan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shear Force ◽  
Structural Model ◽  
Structural Response ◽  
Scanning Electrochemical Microscopy ◽  
Element Model ◽  
Experimental Methodology ◽  
Piezoelectric Wafers ◽  
Electrochemical Microscopy

The incorporation of a shear-force (SF) feedback in scanning electrochemical microscopy (SECM) hardware has enabled topographically resolved electrochemical imaging of electroactive substrates. Despite the versatility of SECM-SF imaging, structural response of the ultra-microelectrode (UME) to various excitation inputs is poorly understood and predictive mathematical models for characterizing dynamic behavior, particularly at high operating frequencies (>100 kHz), are absent. In this article, we present a finite element model to characterize SF behavior by modeling the UME as a rigid cantilever with two distributed piezoelectric wafers (dither and receiver) and demonstrate the model’s ability to predict experimentally observed SF behavior. The obtained SF response under different dither-to-receiver distances for various UME geometries and loading conditions provides insight to the optimum placement of piezoelectric wafers on the UME for achieving a high SF amplitude at SF-sensitive frequencies. In addition, the variations in SF response under different dither-to-receiver orientations indicate the existence of a system transfer function that is dependent on the operating modes of the receiver. The agreement between simulated and experimental results suggests that the finite element model along with the experimental methodology can be extended to automated SF imaging using SECM hardware.

Modelling of Piezoceramic Patches for Actuator Placement Strategies

2014 ◽  
Author(s):  
Michael Rose
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Model ◽  
Electrical Coupling ◽  
Element Model ◽  
Dynamics Simulation ◽  
Tool Chain ◽  
Active Layers ◽  
Speed Up ◽  
Actuator Placement

Piezoceramic Patches are commonly used as actuator devices in smart structures if the induced forces are sufficient for the application. To model these devices in a structural dynamics simulation, a finite element model can be augmented by active layers. This needs a suitable element meshing, taking care of the actual shapes and positions of the active patches in use. If many different setups have to be evaluated, which is naturally the case for placement strategies for suitable actuator positions, this approach is quite cumbersome. To ease and speed up the augmentation of fixed finite element models with piezoceramic patches, so called modal correction methods have been successfully used in this context. These approximative methods avoid the remeshing and the reassembling of the underlying finite element model by adapting the modal description of the structural model with the mass, stiffness and electrical coupling effects of the applied patches. In this paper different aspects of this modelling approach are discussed especially for a tool chain to optimize patch locations in an ASAC simulation environment.

scholarly journals Wind-driven damage localization on a suspension bridge

2016 ◽  
Vol 11 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Marco Domaneschi ◽  
Maria Pina Limongelli ◽  
Luca Martinelli
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Identification ◽  
Structural Response ◽  
Suspension Bridge ◽  
Element Model ◽  
Damage Localization ◽  
Damage Scenarios ◽  
Long Span Bridges ◽  
Long Span

The paper focuses on extending a recently proposed damage localization method, previously devised for structures subjected to a known input, to ambient vibrations induced by an unknown wind excitation. Wind induced vibrations in long-span bridges can be recorded without closing the infrastructure to traffic, providing useful data for health monitoring purposes. One major problem in damage identification of large civil structures is the scarce data recorded on damaged real structures. A detailed finite element model, able to correctly and reliably reproduce the real structure behavior under ambient excitation can be an invaluable tool, enabling the simulation of several different damage scenarios to test the performance of any monitoring system. In this work a calibrated finite element model of an existing long-span suspension bridge is used to simulate the structural response to wind actions. Several damage scenarios are simulated with different location and severity of damage to check the sensitivity of the adopted identification method. The sensitivity to the length and noise disturbances of recorded data are also investigated.

Study of Ship-Ice Collision on Ice Breaker ARAON

2014 ◽  
Author(s):  
Sungchan Kim ◽  
Insik Nho ◽  
Takkee Lee ◽  
Kyungsik Choi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Force ◽  
Structural Response ◽  
Element Model ◽  
Design Data ◽  
Complex Process ◽  
The Impact ◽  
Interaction Behaviors ◽  
Ship Speed

The interaction between a ship and sea ice is a complex process depending on the ice properties, the ice geometry and the relative velocity between the ship and the ice. The effect of important parameters such as ship speed and ice thickness on the impact force are studied by means of finite element model. Idealized ice element types are applied to finite element model in order to survey the impact force and the structural response of icebreaker ARAON subjected to sea ices. Interaction behaviors obtained by finite element model considering the varying parameters are also discussed to compare the numerical results with the design data of ARAON.

scholarly journals Structural Response of Submerged Air-Backed Plates by Experimental and Numerical Analyses

2000 ◽  
Vol 7 (6) ◽  
pp. 333-341 ◽  
Author(s):  
Lloyd Hammond ◽  
Raphael Grzebieta
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Response ◽  
Time History ◽  
Element Model ◽  
Steel Plates ◽  
Small Scale ◽  
History Of ◽  
Structural Responses ◽  
The Finite Element Model

This paper presents the results of a series of small-scale underwater shock experiments that measured the structural responses of submerged, fully clamped, air-backed, steel plates to a range of high explosive charge sizes. The experimental results were subsequently used to validate a series of simulations using the coupled LS-DYNA/USA finite element/boundary element codes. The modelling exercise was complicated by a significant amount of local cavitation occurring in the fluid adjacent to the plate and difficulties in modelling the boundary conditions of the test plates. The finite element model results satisfactorily predicted the displacement-time history of the plate over a range of shock loadings although a less satisfactory correlation was achieved for the peak velocities. It is expected that the predictive capability of the finite element model will be significantly improved once hydrostatic initialisation can be fully utilised with the LS-DYNA/USA software.

Thermo-piezo-elastic analysis of amplified piezoceramic actuators using a refined one-dimensional model

2017 ◽  
Vol 29 (17) ◽  
pp. 3482-3494 ◽  
Author(s):  
Enrico Zappino ◽  
Erasmo Carrera
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Model ◽  
Element Model ◽  
Elastic Analysis ◽  
One Dimensional ◽  
Piezoelectric Effects ◽  
Carrera Unified Formulation ◽  
Strain Stress ◽  
Fully Coupled

The thermo-piezo-elastic analysis of amplified piezoceramic actuators is presented in this article. A refined one-dimensional multi-field finite element model, based on the Carrera Unified Formulation, has been developed. Thermal and piezoelectric effects have been included in the structural model and a fully coupled thermo-piezo-elastic analysis has been performed. The finite element model has been assessed by comparing it with results from open literature The model has also been used to perform the analysis of complex amplified piezoceramic actuators. These actuators are able to amplify the displacements produced by piezoceramic material, but they suffer from high deformations when they undergo high thermal loads. An accurate thermal analysis has been performed to evaluate the strain/stress field. The results show the accuracy of the present model and its capabilities in multi-field analyses.

scholarly journals Structural model updating based on metamodel using modal frequencies

2021 ◽  
Vol 15 (58) ◽  
pp. 114-127
Author(s):  
Jutao Wang ◽  
Zhenzhong Liu ◽  
Liju Xue
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Model ◽  
Model Updating ◽  
Element Model ◽  
Kriging Model ◽  
Frame Structure ◽  
Updating Procedure ◽  
The Finite Element Model

Modal frequencies are often used in structural model updating based on the finite element model, and metamodel technique is often applied to the corresponding optimization process. In this work, the Kriging model is used as the metamodel. Firstly, the influence of different correlation functions of Kriging model is inspected, and then the approximate capability of Kriging model is investigated via inspecting the approximate accuracy of nonlinear functions. Secondly, a model updating procedure is proposed based on the Kriging model, and the samples for constructing Kriging model are generated via the method of Optimal Latin Hypercube. Finally, a typical frame structure is taken as a case study and demonstrates the feasibility and efficiency of the proposed approach. The results show the Kriging model can match the target functions very well, and the finite element model can achieve accurate frequencies and can reliably predict the frequencies after model updating.

scholarly journals Comparison of structural model reduction methods applied to a large-deformation wing box

2021 ◽  
pp. 1-23
Author(s):  
R.R. Medeiros ◽  
C.E.S. Cesnik ◽  
O. Stodieck ◽  
D.E. Calderon ◽  
J.E. Cooper ◽  
...  
Keyword(s):  
Finite Element ◽  
Structural Model ◽  
Structural Response ◽  
Order Reduction ◽  
Element Model ◽  
Computational Effort ◽  
Beam Model ◽  
Wing Structures ◽  
Reduction Methods ◽  
Geometrical Effects

Abstract In this paper, the accuracy and practical capabilities of three different reduced-order models (ROMs) are explored: an enhanced implicit condensation and expansion (EnICE) model, a finite element beam model, and a finite volume beam model are compared for their capability to accurately predict the nonlinear structural response of geometrically nonlinear built-up wing structures. This work briefly outlines the different order reduction methods, highlighting the associated assumptions and computational effort. The ROMs are then used to calculate the wing deflection for different representative load cases and these results are compared with the global finite element model (GFEM) predictions when possible. Overall, the ROMs are found to be able to capture the nonlinear GFEM behaviour accurately, but differences are noticed at very large displacements and rotations due to local geometrical effects.

Nonlinear Strain Estimation Based on Linear Parameters

2018 ◽  
Author(s):  
Bruna Nabuco ◽  
Tobias Friis ◽  
Marius Tarpø ◽  
Sandro Amador ◽  
Evangelos I. Katsanos ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Time Domain ◽  
Structural Model ◽  
Element Model ◽  
Random Loading ◽  
Strain Estimation ◽  
The Time Domain

This paper aims to demonstrate how to estimate strains of fixed structures considering cases with nonlinearities based on parameters determined from one linear case. Both simulated and experimental data have been evaluated. A finite element model was used to obtain the simulated responses. Accelerations and strains were measured along the application of random loading to a fixed structural model for the experimental data. Operational Modal Analysis has been considered in the time domain in order to identify the modal properties. Nonlinearities are included as friction is imposed on the models.

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