Thermomechanical Modelling and Experimental Testing of a Shape Memory Alloy Hybrid Composite Plate

2008 ◽  
Vol 59 ◽  
pp. 41-46 ◽  
Author(s):  
Federica Daghia ◽  
Gabriella Faiella ◽  
Vincenza Antonucci ◽  
Michele Giordano
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Finite Element Model ◽  
Shape Memory ◽  
Functional Properties ◽  
Hybrid Composite ◽  
Experimental Testing ◽  
Element Model ◽  
Electrical Heating ◽  
Simultaneous Generation

Shape memory alloys (SMA) exhibit functional properties associated with the shape memory effect, responsible of the SMA shape recovery after a cycle of deforming-heating and of a simultaneous generation of mechanical work. Composite systems incorporating SMA wires have the ability to actively change shape and other structural characteristics. The functional properties of such adaptive composites are related to the martensitic transformation in the SMA elements and to the constraining behaviour that the composite matrix has on the SMA wires. In this work the behaviour of a shape memory alloy hybrid composite (SMAHC) is numerically and experimentally investigated. A plate was fabricated using prestrained SMA wires embedded in an epoxy resin pre preg glass fibres composite system. Upon calorimetric and mechanical material characterization, a finite element model was used in order to predict the structural behaviour of the SMAHC. In the experimental tests, the plate was clamped at one side and actuated via electrical heating. Temperature and displacement data were collected and compared with the prediction of the finite element model. The results show that the model is able to capture the shape change in the actuation region, although a thorough description of the SMAHC behaviour requires further modelling work, including the simulation of the SMA loading history during composite manufacturing.

Evaluation and Validation of a Multiphysics Finite Element Model for a Piezoelectric Energy Harvester

2021 ◽  
Author(s):  
Andrew Melro ◽  
Kefu Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Model ◽  
Energy Harvester ◽  
Proof Mass ◽  
Experimental Testing ◽  
Element Model ◽  
Load Resistance ◽  
Piezoelectric Energy ◽  
The Finite Element Model

This paper explores the applicability of using the multiphysics finite element method to model a piezoelectric energy harvester. The piezoelectric energy harvester under consideration consists of a stainless-steel cantilever beam attached by a piezoelectric ceramic patch. Two configurations are considered: one without a proof mass and one with a proof mass. Comsol Multiphysics software is used to simultaneously model three physics: the solid mechanics, the electrostatics, and the electrical circuit physics. Several key relationships are investigated to predict the behaviours of the piezoelectric energy harvester. The effects of the electrical load resistance and a proof mass on the performance of a piezoelectric energy harvester are evaluated. Experimental testing is conducted to validate the results found by the finite element model. Overall, the results from the finite element model closely match those from the experimental testing. It is found that increasing the load resistance of the piezoelectric energy harvester causes an increase in voltage across the load resistor, and matching the impedance yields the maximum power output. Increasing the proof mass reduces the fundamental frequency that results in an increase of the displacement transmissibility and the impedance matched resistance. The study shows that the multiphysics finite element method is effective to model piezoelectric energy harvesters.

Numerical Simulation of Solar Array with Shape Memory Alloy in Active Vibration Control

2010 ◽  
Vol 29-32 ◽  
pp. 589-595
Author(s):  
Yong Liang Zhang ◽  
Shou Gen Zhao ◽  
Lun Long ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shape Memory ◽  
Vibration Control ◽  
Closed Loop ◽  
Active Vibration Control ◽  
Element Model ◽  
Solar Array ◽  
Feedback Signal ◽  
Control Laws

The objective of this study is to develop a general design scheme for shape memory alloys (SMA) intelligent structure. The scheme involves dynamic modeling and closed-loop simulation in a finite element environment. First, the structure of multi-body finite element model simulating the real solar array is established. SMA wire is appended on the model. The physical value of the strain, displacement, velocity and acceleration at the sensors locations separately is acted as the feedback signal. The value is multiplied by the control gain to calculate the voltage inputted to SMA wire. The finite element model is then modified to accept control laws and perform closed-loop simulations. Finally numerical examples have demonstrated the efficiency of the vibration control.

Impact damage in composite aircraft structures-experimental testing and numerical simulation

1998 ◽  
Vol 212 (4) ◽  
pp. 245-259 ◽  
Author(s):  
X Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Impact Damage ◽  
Experimental Testing ◽  
Laminated Composite ◽  
Element Model ◽  
Design Tool ◽  
Low Velocity Impact ◽  
Wide Range

This paper describes a strategy for predicting internal damage in a laminated composite structure, when subjected to low-velocity impact. The aim was to obtain a better understanding of and cure for the notorious reduction in strength of aircraft compression panels when they suffered barely visible impact damage (BVID). A finite element model is presented which incorporates the non-linear behaviour due to gross deformation, interlaminar delamination and in-plane fibre and matrix failure. The strategy is validated by impact tests for a wide range of carbon/epoxy composite structures ranging from small stiff plates to realistic aircraft compression panels. It is demonstrated that the finite element model is capable of predicting impact damage in laminated composite structures and thus could be used as a design tool.

A finite element analysis engineering solution to short riveted connections under dynamic loadings

2021 ◽  
pp. 204141962199067
Author(s):  
Aaron Thomas Hill ◽  
Eric Williamson
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Loading ◽  
Experimental Testing ◽  
Element Model ◽  
Physical Models ◽  
Element Analysis ◽  
Engineering Solution ◽  
Using Data

The research presented in this manuscript focuses on the development of an LS-DYNA finite element model to predict the dynamic shear strength of short riveted lap-spliced specimens. Using data collected from experimental testing at the U.S. Army Engineer Research and Development Center (ERDC), a finite element model was developed to replicate the behavior of A502 Grade short riveted connections under quasi-static loading. Subsequent analyses used published Cowper-Symonds constitutive model coefficients to replicate the behavior of these connections under dynamic loading. Computed results were then compared with available test data from ERDC. Given the challenges involved in creating physical models with riveted connections and the abundance of historical bridges constructed with rivets, the developed finite element analysis engineering solution can serve as a critical tool for researchers interested in predicting the response of short riveted connections to dynamic loading and those interested in developing strategies to mitigate against this loading.

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