×
The submission system is temporarily under maintenance. Please send your manuscripts to
Go to Editorial ManagerIndividuals with special needs who use lower limb prostheses (artificial devices designed to replace missing body parts) have specific sociocultural requirements that have driven the development of prosthetic feet. This study conducted a biomechanical analysis of three types of prosthetic feet (SACH, single-axis, and multi-axis) by comparing their biomechanical properties using ground reaction forces and an F-socket. The goal is to enhance prosthetic technology and improve the user experience for below-knee amputees by examining how different foot types affect stresses in below-knee prosthetic limbs during daily activities. The patient case study involves a 28-year-old man weighing 71 kg, who underwent a below-knee amputation of his left limb due to injuries sustained during battles with ISIS. Ground reaction force (GRF) testing is crucial for determining the forces exerted on a patient's feet while walking. Additionally, the Interface Pressure test was performed to measure the pressure between the remaining lower limb and the below-knee prosthetic socket using a pressure sensor. The healthy foot (right leg) served as the reference for comparison. The results of this study on GRF and knee force for various prosthetic feet provide valuable insights into their performance during gait analysis. The multi-axis foot demonstrated superior capabilities, potentially enhancing user mobility and quality of life. Furthermore, the F-socket test indicated that the multi-axis foot offers the best balance of pressure distribution, dynamic performance, and comfort, making it well-suited for adapting to different surfaces necessary for an active lifestyle.
An energy-harvesting hydraulic regeneration suspension system is described in this article, which includes a hydraulic motor, a spool valves, and a hydraulic cylinder. Regenerative actuators are built using a hydraulic transmission system as their inspiration. The proposed regenerative actuator is implemented in the vehicle's non-linear suspension system for a complete model. MATLAB Simulink is utilized to generate and simulate the entire vehicle's regenerative suspension system, which has force properties which are nonlinear with hydraulic actuators equations with energy harvesting from regenerative actuators. During the mathematical simulation, the effect of pressure differential on the spool valve's operation is also taken into account. The quantity of captured energy is compared to the energy expended on the active actuator and the energy generated with the electromagnetic actuator at three distinct input signals at three different pressure level (10, 30 and 50 bars) (random, sinusoidal, and square). The energy generated in the regenerative hydraulic actuator at three pressure levels behaves the same as the active actuator in terms of response, plus the highest pressure of 50 bar is closely comparable to the active system in terms of energy harvest and gradually decreases as the output pressure drops in addition to the behavior of the electromagnetic and its comparison with the wasted energy of the active system.
In this study, loading was carried out for several types of perforated plates, such as circular, rhombic and rectangular holes, where the holes were arranged in two types, namely straight arrangement and alternating arrangement. The stress intensity factor and shape factor were calculated for each case, taking into account the diameter of the holes. So, it is found the SIF increases significantly when the plate is perforated, and the same applies to the shape factor, also increases. In the case of circular holes, the increases in the average value of (SIF) reached to (80.88 %) when the plate was perforated with alternated arranged of circular holes, while the straight arrangement of circular holes the increases of average values of SIF reach to (67.55 %). Either in the case of rhombus holes: the SIF values are increases to (51.07 %) when the plate was perforated with the alternated arrangement, while in the straight arrangement of holes the (SIF) increase to (35.43 %). It was observed through this study, the increases of stress intensity factor and the shape factor with different crack lengths were more stable in the plate that perforated with an alternated arrangement of holes than the straight arrangement. The higher values of stress intensity factor obtained when the plates were perforated with circular holes, due to the circular shape has more stiffness, so the Absorption of force will be small Compared with the rhombus and rectangular shape that will be less stiffness which the absorption of strength is greater.
The extended-finite element method (X-FEM) is used for crack analysis of orthotropic and isotropic functionally- graded composite material (FGCM) plate with slanted crack under thermal loadings. The enrichments functions of discontinuity are implemented. Mixed-mode SIFs are calculated in isotropic and orthotropic FGMs. Gaussian technique (Q4) has been applied in numerical calculation of interaction of solution. Thermal effects, fundamental equations, the interaction integral of non-homogeneous cases (M-integral), and proposal numerical integration rule are set to simulate and to debate the accuracy of the present work results in comparing with the results of the references that available in the literature. In addition, the effect of size of crack is studied to discuss the values of energy release rate and stress intensity factors with different crack angles. The present study is implemented by using MATLAB program to present steady state thermo XFEM fracture analysis of isotropic and an isotropic FG plate with inclined center crack.