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Growing age and different conditions often require the replacement of orthoses, and FDM-based 3D printing can produce them quickly with less investment. In today's market for orthotics, these characteristics are highly desired. Therefore, this study is fully focused on the optimization and strength analysis of FDM 3D-printed ankle–foot orthoses (AFO) fabricated using PLA and PLA reinforced with carbon fiber (PLA-C). An increase in ankle plantar-flexor force can be achieved by reinforcing thermoplastic AFOs with CFs. Specially designed mechanical strength tests were conducted at the UTM to generate force–displacement curves for stored elastic energy and fracture studies. The mechanical behavior of both AFOs was predicted with the help of an FEA. The model predictions were validated by comparing them with mechanical strength testing conducted under the same loading and boundary conditions as the FEA. In both the prediction and experimental analysis, the PLA-C-based AFOs were stiffer and could withstand greater loads than the PLA-based AFOs. An area of high stress in the simulation and a fracture point in experimentation were both found at the same location. Furthermore, these highly accurate models will allow the fabrication of AFOs to be improved without investing time and resources on trials. [ABSTRACT FROM AUTHOR]

This study investigated the effect of abrasive water jet kinematic parameters, such as jet traverse speed and water pressure, on the surface of magnesium-based metal matrix nanocomposites (Mg-MMNCs) reinforced with 50 nm (average particle size) Al2O3 particles at concentrations of 0.66 and 1.11 wt.%. The extent of grooving caused by abrasive particles and irregularities in the abrasive waterjet machined surface with respect to traverse speed (20, 40, 250 and 500 mm/min), abrasive flow rate (200 and 300 g/min) and water pressure (100 and 400 MPa) was investigated using surface topography measurements. The results helped to identify the mode of material disintegration during the process. The nanoindentation results show that material softening was decreased in nanocomposites with higher reinforcement content due to the presence of a sufficient amount of nanoparticles (1.11 wt.%), which protected the surface from damage. The values of selected surface roughness profile parameters—average roughness (Ra), maximum height of peak (Rp) and maximum depth of valleys (Rv)—reveal a comparatively smooth surface finish in composites reinforced with 1.11 wt.% at a traverse speed of 500 mm/min. Moreover, abrasive waterjet machining at high water pressure (400 MPa) produced better surface quality due to sufficient material removal and effective cleaning of debris from the machining zone as compared to a low water pressure (100 MPa), low traverse speed (5 mm/min) and low abrasive mass flow rate (200 g/min). [ABSTRACT FROM AUTHOR]