In the frame of technology development, fused deposition modeling is adapted in this study to elaborate composite material from 20% short carbon fiber reinforced polyether ether ketone (CF/PEEK) filament. This printing technology has attached widespread intention as it provides a rapid prototyping parts with high performances in diverse fields. For this purpose, a set of experimental tensile and bending tests are carried out to focus on the effect of printing orientation on the mechanical properties of the designed samples. Three raster angles are considered in this investigation: 0°, ±45°, and 90°. The obtained results indicate that the printing orientation of 0°, which is parallel to the tensile loading path and perpendicular to the flexural one exhibits higher mechanical strength compared to the other orientations. Evolution of Young modulus, total elongation at failure, yield and ultimate strengths as well as deflection are also discussed. Experimental work is supported by numerical simulation and a good agreement is revealed. Microstructural analysis is performed in order to argue the observed mechanical behavior. Through the fractured section morphology, the effect of tensile loading on CF/PEEK microstructure, at various printing orientation is emphasized.

The present paper proposes a mathematical development of the plasticity and damage approaches to simulate sheet metal forming processes. It focuses on the numerical prediction of the deformation of the sheet metal during the deep drawing process when a crack appears. Anisotropic plasticity constitutive equations are proposed. A fully implicit integration of the coupling constitutive equations is used and leads to two nonlinear local scalar equations that are solved by Newton’s method. The developed model allows predicting the onset of cracks in sheet metals during cold forming operations. The numerical model is implemented in ABAQUS software using user-defined subroutines, which are VUMAT and UMAT. The accuracy of the anisotropic elastoplastic model fully coupled with ductile damage is evaluated using numerical examples.

In recent years, impact-resistant structures are highly sought after in various fields such automotive and aerospace applications as they proved notable performances, garnering significant success. The aim of this study is to assess the behavior of the 3D-printable honeycombs subjected to low velocity impact, for providing insights into absorbed energy for different core designs: hexagonal, auxetic, and rectangular, considering an equal number of cells across all designs. This work reports the computational and experimental studies conducted for sandwich structures under different impact loading. The experimental impact tests are carried out using a drop weight impact-testing machine. The examined specimen comprises two face-sheets and architected cell core fabricated through the Fused Filament Fabrication (FFF) process made of polylactic acid (PLA). Variations in the geometric design of the cells result in the formation of cores with auxetic and non-auxetic topologies. Uniaxial tensile tests are performed to identify the mechanical properties of the involved biopolymer. The second attempt consists on comparing three architectural core structures under impact test using experimental and computational methods. Our findings highlight the specific influence of core topology on energy absorption in 3D-printed sandwich structures. Results indicate that while all three configurations (hexagonal, re-entrant, and rectangular) demonstrate comparable energy absorption values, the specific mechanisms and efficiencies vary, with re-entrant cores exhibiting distinct behaviors under impact.

The main motivation for the present work is to provide an improved description of the response of Functionally Graded (FG) structures under a spherical indenter, considering material nonlinearities. This is achieved through the implementation of elastoplastic material behavior using integration points to avoid the division of the structure into multiple layers. The current paper proposes a numerical investigation into the mechanical response of functionally graded materials (FGMs) in contact with a rigid hemispherical head indenter. The numerical model considers both the Mori–Tanaka model and self-consistent formulas of Suquet to accurately model the smooth variation of material properties through the thickness of the elastoplastic FG material. The model execution involves a UMAT user material subroutine to implement the material behavior into ABAQUS/Standard. The user material UMAT subroutine is employed to introduce material properties based on the integration points, allowing for an accurate representation and analysis of the material’s behavior within the simulation. The developed numerical model is validated through a comparison with experimental results from the literature, showing a good correlation that proves the efficiency of the proposed model. Then, a parametric study is conducted to analyze the effect of the indenter dimension, the indentation depth and the gradient index on the indentation force, the contact pressure evolution, von Mises equivalent stress and equivalent plastic strain distributions located on the vicinity of the contact zone. The results showed that the elastoplastic response of TiB/Ti FG plates is significantly influenced by the gradient index, which determines the properties of the FG composite through the thickness. These results may help development engineers choose the optimal gradation for each industrial application in order to avoid contact damage.