scholarly journals Strain Optical Analysis of 3D Printing Elements in Different Additive Technologies in Comparison with the Finite Element Method

2018 ◽  
Vol 2018 (3) ◽  
pp. 49-68
Author(s):  
Ewelina Kluska ◽  
Piotr Gruda ◽  
Natalia Majca-Nowak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
3D Printing ◽  
Strain Analysis ◽  
Additive Technologies ◽  
Image Correlation ◽  
Optical Methods ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Element Method

Abstract Research included in this article were conducted with a project: ‘Additive technology used in conduction with optical methods for rapid prototyping of 3D printed models’. In this article intellectualized three various 3D printing technologies: Fused Deposition Modelling (FDM), Selective Laser Sintering (SLS) and Material Jetting (PolyJet). Also, there was presented theory of Digital Image Correlation (DIC) as an optical method for strain analysis. The limitations of DIC system have been tested and detected. The test result for DIC system were shown for each method of additive technologies and the results were compared to Finite Element Method (FEM). Test specimens were printed in selected technologies for reference. DIC system has been used for displacement state in loaded objects. The last paragraph contains both summary and tests results.

scholarly journals Stress and strain analysis from dynamic loads of mechanical hand using finite element method

2018 ◽  
Vol 352 ◽  
pp. 012017 ◽  
Author(s):  
Iskandar Hasanuddin ◽  
Husaini ◽  
M. Syahril Anwar ◽  
B.Z. Sandy Yudha ◽  
Hasan Akhyar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain Analysis ◽  
Dynamic Loads ◽  
Stress And Strain ◽  
Mechanical Hand ◽  
Element Method

Nonhomogeneous Ventricular Wall Strain: Analysis of Errors and Accuracy

1993 ◽  
Vol 115 (4B) ◽  
pp. 497-502 ◽  
Author(s):  
Lewis K. Waldman ◽  
Andrew D. McCulloch
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Measurement Errors ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Noninvasive Methods ◽  
Single Plane ◽  
Cardiac Deformation ◽  
Cardiac Strain ◽  
Element Method

Nonhomogeneous distributions of strains are simulated and utilized to determine two potential errors in the measurement of cardiac strains. First, the error associated with the use of single-plane imaging of myocardial markers is examined. We found that this error ranges from small to large values depending on the assumed variation in stretch. If variations in stretch are not accompanied by substantial regional changes in ventricular radius, the associated error tends to be quite small. However, if the nonuniform stretch field is a result of substantial variations in local curvature from their reference values, large errors in stretch and strain occur. For canine hearts with circumferential radii of 2 to 4 cm, these errors in stretch may be as great as 30 percent or more. Moreover, gradients in stretch may be over- or underestimated by as much as 100 percent. In the second part of this analysis, the influence of random measurement errors in the coordinate positions of markers on strains computed from them is studied. Arrays of markers covering about 16 cm2 of ventricular epicardium are assumed and nonuniform stretches imposed. The reference and deformed positions of the markers are perturbed with Gaussian noise with a standard deviation of 0.1 mm, and then strains are computed using either homogeneous strain theory or a nonhomogeneous finite element method. For the strain distributions prescribed, it is found that the finite element method reduces the error resulting from noise by about 50 percent over most of the region. Accurate measurements of cardiac strain distributions are needed for correlation with and validation of realistic three-dimensional stress analyses of the heart. Moreover, with the advent of increasingly effective noninvasive methods to measure cardiac deformation such as magnetic resonance imaging, the use of nonhomogeneous strain analysis to determine more accurate strain distributions has increasing clinical significance.

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