This study examined the mechanical performance of 3D-printed, fiber-reinforced composites with a rectangular shape and a hole at one end. Nyon-6 was selected as a polymer matrix, and glass or Kevlar fibers were selected as continuous fibers due to their wide range of applications. Nylon is an engineering thermoplastic; reinforcing it with fibers, such as glass fiber or Kevlar, can significantly improve its mechanical properties. An analytical model was constructed based on the volume average stiffness approach to predict the mechanical properties of 3D-printed specimens. A numerical model was built to predict failure modes and damage in 3D-printed specimens with different fiber orientations. The stress–strain relationship was linear in all composites. For Kevlar-based composites, the maximum stress was 1.7 MPa, 3.62 MPa, 2.2 MPa, 1.0 MPa, and 1.4 MPa for the orientation angles of 0°, 22.5°, 45°, 67.5°, and 90°, respectively. Overall, Kevlar-based composites exhibited mechanical properties superior to those of glass-based composites. The effect of the fiber orientation was also different between the two systems. The simulation results predicted that the failure propagation begins in the areas close to the hole. Notably, the level of agreement between the simulated and experimental results varied depending on the fiber type and orientation, reflecting the complex interplay between multiple fibers, matrix interactions, and stress transfer.

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Strolling is a complex activity that requires the synchronization of the brain, anxiety, and muscles, as well as rhythmic movement of the lower limbs. Gait may be abnormal if coordination is disrupted. As a result, exoskeletons should be used to treat it effectively. The connection and other systems contained in the exoskeletons could be used to mimic the behavior of the human lower leg. These mechanisms are created utilizing complex traditional methods. This study proposes a new gait-inspired method based on a genetic algorithm (GA) for synthesizing a four-bar mechanism for exoskeletons. For each phase of the gait, the trajectory is calculated and merged using optimization algorithms. Each phase of the trajectory passes through 10 precision points, for an entirety of 20 precision points in 1 gait cycle. For the problem under consideration, it is discovered that the GA outperforms other literature techniques. Finally, the proposed design for a lower limb exoskeleton is depicted as a solid model. Furthermore, the generated link-age accurately tracks all the transition points, and the simulation of the planned linkage for one gait cycle has been illustrated using a stick diagram.

Over the past few years, the popularity of graphene as a potential 2D material has increased since graphene-based materials have applications in a variety of fields, including medicine, engineering, energy, and the environment. A large number of graphene sheets as well as an understanding of graphene’s structural hierarchy are critical to the development of graphene-based materials. For a variety of purposes, it is essential to understand the fundamental structural properties of graphene. Molecular descriptors were used in this study to investigate graphene sheets’ structural behaviour. Based on our findings, reverse degree-based molecular descriptors can significantly affect the exchange-correlation energy prediction. For the exchange-correlation energy of graphene sheets, a linear regression analysis was conducted using the reverse general inverse sum indeg descriptor, RGISI(p,q). From RGISI(p,q), a set of reverse topological descriptors can be obtained all at once as a special case, resulting in a model with a high correlation coefficient (R between 0.896 and 0.998). Used together, these reverse descriptors are graphed in relation to their response to graphene. Based on this study’s findings, it is possible to predict the exchange correlation energy as well as the geometric structures of graphene sheets with very little computational cost.

To meet energy-saving requirements, in recent years, Saudi Arabia’s construction industry has focused on researching the use of naturally available resources as raw materials. This study looks at the behavior of Viroc, specifically using pinewood and its compression properties in eco-friendly concrete. The study demonstrates the feasibility of adding pinewood to concrete and provides a theoretical basis for the promotion of dry pinewood particles and Portland cement composite materials. The Viroc specimens used in the study are 18 mm long, 12 mm wide, and 12 mm deep. The mechanical properties of the specimens were tested and compared by using a universal testing machine (UTM) and the Ansys software program 2022. The test results show that Viroc can increase the compression strength and modulus of the construction material as well as increase its brittleness and toughness (mechanical properties). The results show that it is feasible to incorporate wood and cement, resulting in a new type of Viroc composite material in an eco-friendly environment.