Mechanical behavior of composite materials using the finite element analysis

A finite element analysis software has been used in order to determine several mechanical properties for samples made from unidirectional composite materials. Plates from reinforced unidirectional fiber glass polymer composites obtained by compression hand lay-up process were studied. Tensile tests were performed upon samples with different number and orientation of the composite ply layup

Mechanical behavior of composite materials using the finite element analysis

A finite element analysis software has been used in order to determine several mechanical properties for samples made from unidirectional composite materials. Plates from reinforced unidirectional fiber glass polymer composites obtained by compression hand lay-up process were studied. Tensile tests were performed upon samples with different number and orientation of the composite ply layup

MEDICAL MANUFACTURING INNOVATIONS

The purpose of these studies was to improve the design and manufacturing process by selective laser melting, of new medical implants. After manufacturing process, the implants were measured, microscopically and mechanical analyzed. Implants manufactured by AM can be an attractive option for surface coatings to improve the osseointegration process. The main advantages of customized implants made by AM process are: the precise adaptation to the region of implantation, better cosmesis, reduced surgical times and better performance over their generic counterparts. These medical manufacturing changes the way that the surgeons are planning surgeries and engineers are designing custom implant. AM process has eliminated the constraints of shape, size, internal structure and mechanical properties making it possible for fabrication of implants that conform to the physical and mechanical requirements of implantation according to CT images. This article will review some custom implants fabricated in DME using biocompatible titanium

Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach

Calcium nitrate is considered a promising accelerator in cement-based composites, with high potential in 3D printing and cold cement concreting. The effect induced by the composition of calcium nitrate tetrahydrate (CN) accelerator into white Portland cement is evaluated here from three perspectives: (1) Fresh cement paste properties in terms of setting time and slump, (2) mechanical properties of hardened cement samples at 7 and 28 days and (3) material characteristics in terms of structure and porosity that further link the presence of the accelerator with the macroscopic performances. The compressive and flexural strength of the hardened samples, evaluated after 7 and 28 days of hydration, indicate a non-monotonous trend with CN concentration. Crystalline phase composition is investigated using X-ray diffraction (XRD). The morphology and texture are analyzed at the flexure interface by visual inspection and electron microscopy. Complementary, the porous features are investigated by NMR-relaxometry on dry and cyclohexane-filled samples. The studies confirm that CN promotes changes in the composition and morphology of hydrates, while a trend of increase in capillary porosity is outlined as well. This competition between multiscale effects may be quantified by NMR and complementary techniques to further clarify the mechanical behavior of such composites

Finite Element Analysis of Different Osseocartilaginous Reconstruction Techniques in Animal Model Knees

Lesions of the articular cartilage are frequent in all age populations and lead to functional impairment. Multiple surgical techniques have failed to provide an effective method for cartilage repair. The aim of our research was to evaluate the effect of two different compression forces on three types of cartilage repair using finite element analysis (FEA). Initially, an in vivo study was performed on sheep. The in vivo study was prepared as following: Case 0—control group, without cartilage lesion; Case 1—cartilage lesion treated with macro-porous collagen implants; Case 2—cartilage lesion treated with collagen implants impregnated with bone marrow concentrate (BMC); Case 3—cartilage lesion treated with collagen implants impregnated with adipose-derived stem cells (ASC). Using the computed tomography (CT) data, virtual femur-cartilage-tibia joints were created for each Case. The study showed better results in bone changes when using porous collagen implants impregnated with BMC or ASC stem cells for the treatment of osseocartilaginous defects compared with untreated macro-porous implant. After 7 months postoperative, the presence of un-resorbed collagen influences the von Mises stress distribution, total deformation, and displacement on the Z axis. The BMC treatment was superior to ASC cells in bone tissue morphology, resembling the biomechanics of the control group in all FEA simulations