Local scale fracture characterization of an advanced structured material manufactured by fused deposition modeling in 3D printing.

Abstract

Additive manufacturing (AM) is a promising way to produce complex structures by adding layers. AM arises great interest both in industrial and academic sectors to develop new advanced structured materials. To benefit from its advantages, it is important to accurately characterize the mechanical properties of the obtained structures in order to ensure their integrity during operation. It becomes important to characterize these structures at the local scale (micron and/or the nanometer scale). In the specific case of polymeric materials produced by Fused Deposition Modeling (FDM), the comprehension of the mechanical behavior between adjacent layers during deformation can help to improve mechanical properties. However, few studies in the literature have focused on implementing approaches to characterize local strains at the surface of these materials. In this study, an original approach based on the use of a speckle pattern with particles average

Crack growth measurement and J‐integral evaluation of additively manufactured polymer using digital image correlation and FE modeling

“…White speckles with micrometric dimensions were deposited using an airbrush (speckle diameter varying between 10 and 30 μm with an average of 20 μm (see Figure 1D). 36 …”

“…The so-called mini single edge notch tension (mini-SENT) specimen is first introduced. The microscale experiment analyzed via DIC enables surface displacement and strain fields to be measured 35,36 . To study the effect of the underlying mesostructure on the fracture properties of additively manufactured materials, numerical tools are developed herein to make the best use of microscale experimental results.…”

Longitudinal fracture analysis of inhomogeneous beams with continuously varying sizes of the cross-section along the beam length

“…The strain energy density in the un-cracked beam portion, 02 u , is found by replacing of  with d  in formula (17). Finally, by substituting of  and U in (11), one obtains the following expression for the strain energy release rate:…”

“…The analysis is carried-out assuming non-linear elastic mechanical behavior of the material. One of the motives for the present paper is the fact that certain kinds of inhomogeneous materials, such as functionally graded materials, can be built-up layer by layer [11,12] which is a premise for appearance of longitudinal cracks between layers. It should be mentioned that the previous works of the author are concerned with longitudinal fracture analyses of inhomogeneous (functionally graded) beam configurations with constant sizes of the cross-section along the beam height [16 -19].…”