scholarly journals Thermo-responsive and shape-morphing CF/GF composite skin: Full-field experimental measurement, theoretical prediction, and finite element analysis

2021 ◽  
Vol 160 ◽  
pp. 106874
Author(s):  
Jamal Seyyed Monfared Zanjani ◽  
Pouya Yousefi Louyeh ◽  
Isa Emami Tabrizi ◽  
Abdulrahman Saeed Al-Nadhari ◽  
Mehmet Yildiz
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Prediction ◽  
Experimental Measurement ◽  
Element Analysis ◽  
Full Field ◽  
Shape Morphing

scholarly journals Eliminating Underconstraint in Double Parallelogram Flexure Mechanisms

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Robert M. Panas ◽  
Jonathan B. Hopkins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Measurement ◽  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Average Error ◽  
Static Stiffness ◽  
Element Analysis ◽  
Linkage Design ◽  
Analytical Expressions

We present an improved flexure linkage design for removing underconstraint in a double parallelogram (DP) linear flexural mechanism. This new linkage alleviates many of the problems associated with current linkage design solutions such as static and dynamic performance losses and increased footprint. The improvements of the new linkage design will enable wider adoption of underconstraint eliminating (UE) linkages, especially in the design of linear flexural bearings. Comparisons are provided between the new linkage design and existing UE designs over a range of features including footprint, dynamics, and kinematics. A nested linkage design is shown through finite element analysis (FEA) and experimental measurement to work as predicted in selectively eliminating the underconstrained degrees-of-freedom (DOF) in DP linear flexure bearings. The improved bearing shows an 11 × gain in the resonance frequency and 134× gain in static stiffness of the underconstrained DOF, as designed. Analytical expressions are presented for designers to calculate the linear performance of the nested UE linkage (average error < 5%). The concept presented in this paper is extended to an analogous double-nested rotary flexure design.

Shear Test on CFRP Full-Field Measurement and Finite Element Analysis

2010 ◽  
Vol 112 ◽  
pp. 49-62 ◽  
Author(s):  
Sébastien Mistou ◽  
Marina Fazzini ◽  
Moussa Karama
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Modulus ◽  
Shear Test ◽  
Image Correlation ◽  
Optical Methods ◽  
Strain Gauges ◽  
Element Analysis ◽  
Full Field ◽  
Full Field Measurement

The purpose of this work is to study the Iosipescu shear test and more precisely its ability to characterize the shear modulus of a carbone/epoxy composite material. The parameters influencing this identification are the fibre orientation, the geometry of the notch and the boundary conditions. Initially these parameters were studied through the finite element analysis of the shear test. Then, the measurement of the shear strains was carried out by traditional methods of measurement (strain gauges) but also by optical methods. These optical methods: the digital image correlation and the electronic speckle pattern interferometry (ESPI); allow for various levels of loading, to reach a full-field measurement of the shear strain. This enabled us to study the strain distribution on the section between the two notches. The finite element model enabled us to study the parameters influencing the calculation of the shear modulus in comparison with strain gauges, image correlation and ESPI. This work makes it possible to conclude on optimal parameters for the Iosipescu test.

Triangulation Based Digitizing of Tooling and Sheet Metal Part Surfaces - Measuring Technique, Analysis of Deviation to CAD and Remarks on Use of 3D-Coordinate Fields for the Finite Element Analysis

2007 ◽  
Vol 344 ◽  
pp. 847-853 ◽  
Author(s):  
J. Hecht ◽  
K. Lamprecht ◽  
Marion Merklein ◽  
Konstantin Galanulis ◽  
J. Steinbeck
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Discrete State ◽  
Full Field ◽  
The Finite Element Analysis ◽  
Hydroforming Process ◽  
Fringe Patterns ◽  
Formed Part ◽  
The Impact

The dynamic development of highly accurate optical measuring machines within the last years pushed the introduction of digitizing techniques to many applications in the fields of quality control, reverse engineering and rapid prototyping. By projecting fringe patterns onto the object's surface and recording pictures of the curvature dependant deformation of the pattern, 3D coordinates for each camera pixel are calculated on the basis of the principle of triangulation. The generation of a polygon mesh can be used for the analysis of the deviation of a die or a formed part to the initial CAD data, i.e. by means of full field or section based comparison. This paper presents the application of the above mentioned techniques on a double sheet hydroforming process. The gathered 3D data of the clam-shell part as well as of the tooling dies served for the calculation of the deviation to the respective reference geometry. With respect to the utilization of digitized tooling data within the finite element analysis, further investigations were performed on the impact of data reduction strategies. Aiming on the minimization of the necessary number of elements, representing the tooling surface in a discrete state, and on the request for a sufficient degree of accuracy, these strategies have to be considered of high priority.

A Development of Polarization Experimental Processes and Analysis Mechanical Behavior for COC and PVDF Films

2012 ◽  
Vol 538-541 ◽  
pp. 33-36
Author(s):  
Chien Chang Lin ◽  
Feng Min Lai ◽  
Chen Mao Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Experimental Measurement ◽  
Material Properties ◽  
Thin Plates ◽  
Coating Film ◽  
Element Analysis ◽  
Analysis Techniques ◽  
Piezoelectric Polymer

The paper is investigated the polarization properties and mechanical behavior of new piezoelectric polymer material plates by experimental procedures and finite element analysis. In this study, the PVDF materials is used to produce the piezoelectric polymer layer and the coating film, we have provided a nice procedures for manufacturing piezoelectric polymer plates (PVDF). In order to find the proper proportion of the PVDF to achieve the best material properties, the mechanical behavior of displacements and stresses for the electrets is investigated by experimental measurement and finite element analysis (with ANSYS). It is investigated whether the thicknesses of specimens are affected the polarization. The paper is presented modal analysis techniques for piezoelectric thin plates.

Direct Study of the Thermal Conductivity in Aluminum Nanowires

2009 ◽  
Vol 1221 ◽  
Author(s):  
Nenad Stojanovic ◽  
D.H.S. Maithripala ◽  
Jordan M. Berg ◽  
Mark Holtz
Keyword(s):  
Thermal Conductivity ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Electrical Resistivity ◽  
Thermal Properties ◽  
Electron Transport ◽  
Theoretical Prediction ◽  
Room Temperature ◽  
Total Thermal Conductivity ◽  
Element Analysis

AbstractThermal conductivity and electrical resistivity of 1 μm long aluminum nanowires, 75, 100, and 150nm in width and 100nm thick, were measured at room temperature. The method consists of microfabricated electrothermal test devices and a model-based data processing approach using finite-element analysis (FEA). The electrical and thermal properties of the nanowires differ significantly from bulk values while electrical resistivity agrees well with theoretical prediction. Electron transport equation models, which adequately describe the resistivity data, consistently underestimate the thermal conductivity. Incorporating a phonon contribution of ˜ 21 W/m·K to the total thermal conductivity is found to accurately describe the measured values.

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