Designing and manufacturing replacement cancellous bone structures by lattice structures and Additive Manufacturing (AM) techniques is an effective method to create lightweight orthopedic implants while ensuring that they are mechanically compatible and their osseointegration ability with the host bone. In this article, we suggest a new design based on three lattice structures from triply periodic minimal surfaces (TPMS) with a different volume porosity to replace cancellous bone based on predicting the mechanical stiffness. To predict the mechanical stiffness, the relationship between the effective modulus of elasticity and different porosity ratios of the lattice structures was determined by using three methods: i) finite element modeling (FEM) simulation, ii) Gibson and Ashby method and iii) a uniaxial compression test after manufacturing the lattice structures by using Fused Filament Fabrication (FFF) Technology. To demonstrate the efficiency of our approach, the comparison of both numerical and experimental results showed that the effect of structure difference and porosity ratio of lattice structures on the mechanical stiffness values effectively match the cancellous bone in terms of elastic modulus and porosity ratio.

The turbine blades are subjected to high operating temperatures and high centrifugal tensile stress due to rotational speeds. The maximum temperature at the inlet of the turbine is currently limited by the resistance of the materials used for the blades. The present paper is focused on the thermo-mechanical behavior of the blade in composite materials with reinforced mast under two different types of loading. The material studied in this work is a composite material, the selected matrix is a technical ceramic which is alumina (aluminum oxide Al2O3) and the reinforcement is carried out by short fibers of high modulus carbon to optimize a percentage of 40% carbon and 60% of ceramics. The simulation was performed numerically by Ansys (Workbench 16.0) software. The comparative analysis was conducted to determine displacements, strains and Von Mises stress of composite material and then compared to other materials such as Titanium Alloy, Stainless Steel Alloy, and Aluminum 2024 Alloy. The results were compared in order to select the material with the best performance in terms of rigidity under thermomechanical stresses. While comparing these materials, it is found that composite material is better suited for high temperature applications. On evaluating the graphs drawn for, strains and displacements, the blade in composite materials reinforced with mast is considered as optimum.

Designing and manufacturing lattice structures with Topology Optimization (TO) and Additive Manufacturing (AM) techniques is a novel method to create light-weight components with promising potential and high design flexibility. This paper proposes a new design of lightweight-graded lattice structures to replace the internal solid volume of the turbine blade to increase its endurance of high thermal stresses effects. The microstructure design of unit cells in a 3D framework is conducted by using the lattice structure topology optimization (LSTO) technique. The role of the LSTO is to find an optimal density distribution of lattice structures in the design space under specific stress constraints and fill the inner solid part of the blade with graded lattice structures. The derived implicit surfaces modelling is used from a triply periodic minimal surfaces (TPMS) to optimize the mechanical performances of lattice structures. Numerical results show the validity of the proposed method. The effectiveness and robustness of the constructed models are analysed by using finite element analysis. The simulation results show that the graded lattice structures in the improved designs have better efficiency in terms of lightweight (33.41–40.32%), stress (25.52–48.55%) and deformation (7.35–19.58%) compared to the initial design.

This work is a study of the elastic fields’ effect (stresses and displacements) caused by dislocations networks at a heterostructure interface of a InAs / GaAs semiconductors thin system in the cases of isotropic and anisotropic elasticity. The numerical study of this type of heterostructure aims to predict the behavior of the interface with respect to these elastic fields satisfying the boundary conditions. The method used is based on a development in Fourier series. The deformation near the dislocation is greater than the other locations far from the dislocation.     

Electrochemical methods, weight loss and surface analysis technique were used to study the effect of glutamic acid on the corrosion of Fe-19Cr stainless steel in 1 M hydrochloric acid solution. Results revealed that the corrosion inhibition of glutamic acid of Fe-19Cr in 1 M HCl was enhanced in the presence of the iodide ions due to synergistic effect. In the absence of KI, the inhibition of Fe-19Cr corrosion by glutamic acid was glutamic acid concentration dependent. Potentiodynamic polarization curves demonstrated that glutamic acid acts as a mixed type inhibitor. Self-Assembled Monolayers of glutamic acid were able to protect stainless steel from corrosion effectively. The adsorption of the inhibitor onto the stainless steel surface follows Langmuir adsorption isotherm. The value of free energy of the adsorption indicated that there is a physical interaction between the glutamic acid and the stainless steel surface.

During turning operations, tool-part-chip contact causes wear to the cutting tool. The objective of this work is to study the wear of the clearance faces of tungsten carbide cutting tools during turning operations. Experimental tests on tool life for dry turning operations were carried out at four different cutting speeds, where the feed rate and the depth of cut are kept at constant values: 0.08 mm/rev for feed rate and 0.5 mm for depth of cut. An analysis of the influence of cutting parameters on the tools wear and consequently tool life (Τ) was presented, then the roughness of the machined surface Ra and the morphology of the chips produced were studied. This study makes it possible to identify that the wear mechanisms and the tool life are strongly linked to the roughness of the machined surfaces and to the morphology of the chips produced during the turning operations.

In this work we present a new biomimetic disc prosthesis imitating the fibroreinforced osmotic, and viscoelastic properties of the biological intervertebral disc (BID). For this, we proposed to study the second-generation biomimetic prosthesis "the M6-C prosthesis" which contains two metal plates, a core and a fiber fabric. First, a 3D model was established, the finite element analysis (FEA) under the ANSYS©2015 was conducted. Secondly, a biomimetic material, the silicone rubber, was compared with the polyethylene to find the material that mimics the behavior of a biological disk. Finally, the analysis of the results found the polymer has the same mechanical properties as the nucleus pulposus, in particular the viscoelastic behaviour compared with that of polyethylene

In this investigation, a new simple triangular strain based membrane element with drilling rotation for 2-D structures analysis is proposed. This new numerical model can be used for linear and dynamic analysis. The triangular element is named SBTE and it has three nodes with three degrees of freedom at each node. The displacements field of this element is based on the assumed functions for the various strains satisfying the compatibility equations. This developed element passed both patch and benchmark tests in the case of bending and shear problems. For the dynamic analysis, lumped mass with implicit/explicit time integration are employed. The obtained numerical results using the developed element converge toward the analytical and numerical solutions in both analyses.