Firas Thair Raoof Al-Malik

The current work involved optimizing the spars of wind turbine blades while taking into account the wind speed quantities that affected the blade structure. The objective was to determine the optimal dimensions of turbine blade spar configurations using the finite element method under the influence of the maximum pressure associated with the first mode shape while maintaining the Von Misses stresses within the assumed safety factor (1.5).(200-230 MPa). The blade was stiffened with a main box spar and two auxillary spars on each side. Appropriate spar locations were specified for poisons with a high natural frequency first mode. The blade parts' dimensions were discretized to allow for greater flexibility and precision in dimension assignment. By utilizing the ANSYS program, the optimization process required a certain number of iterations to modify the blade structure's dimensions. Optimized iteration was considered in order to increase the thickness in areas of high stress and decrease the thickness in areas of low stress. Additionally, a comparison between a blade structure with optimal dimensions and one with non-optimal dimensions was included.

The present study includes of prediction the cracks and it is lengths in aluminum plates. The final finite element mesh of model with total number of nodes was generated in ANSYS 18.2 program to estimate the free vibration response on open edge crack plate. A set of crack’s plates were subjected to modal analysis with various boundary conditions to estimate the natural frequencies for three modes. The results obtained from this analysis showed that cracks propagation could be detected due to change in natural frequencies for three modes. It can be observation the effect of crack’s on the stiffness of structure by studied the stress intensity of finite plate with various crack’s length under free vibration. Consequently, this study provides a useful techniques of prediction cracks length via change in dynamic response of structure for different boundary conditions.

The aim of this study is to build a MATLAB code to predict the interlaminar radial strains, and stresses developed in a laminated composite tube. This code is only valid for symmetrical laminated composite tubes. The code can solve for tube that is subjected to uniform internal pressure. The written MATLAB code can save time and money compared to experiments and finite element simulations. Then, this code is validated with other published mentioned articles in this study. Good agreement is achieved which it means the built code can be used for the cases that agree with a symmetrical condition. The code is run to solve for radial, hoop, and shear strains. Also, it is used to solve for axial, radial, hoop, and shear stresses.

The purpose of this study was to develop an artificial neural network (ANN) model for predicting the flexion moment in knee prosthesis during the gait cycle. It was decided to employ the feedforward backpropagation (BP) algorithm as an adaptive method in ANN. Two types of prosthetic knee joints were employed in this study, a mechanical model (3R60) and a microprocesses model (C-Leg4). Three inputs parameters were used in building the ANN model. This involved, the vertical ground reaction force (vGRF), hip angle and knee angle. The vGRF was measured on the treadmill using Zebris FDM-T system. While, the data of knee angle and hip angle were estimated for prosthetic knee joints using Kinovia program. The flexion moment in knee joint was selected as target parameter for ANN model. Finally, the verification results demonstrate the feasibility and efficiency of ANN model in prediction the flexion moment in different types of knee prosthesis. Furthermore, there is a good compatible in data of knee flexion moment between microprocessor-controlled prosthetic knee joints with the intact limb which help in improve many of gait features and reduce hip work production.

When a transfemoral amputee missing his knee joint, a polycentric mechanism is used as technical substitute to restore the gait function. The motion ability of transfemoral amputee is dependent on the performance of prosthetic knee. Recent results on the kinematic analysis of four-bar polycentric knee mechanism are reviewed in this article. Different experimental tests on data of above-knee prosthetic limb such as F-socket, gait analysis, ground reaction force, static loading, fatigue life and static prosthetic alignment, etc., were used to analyse the gait cycle and to improve the comfortability of amputee after using prosthetic limb, and to increase the stability of prosthetic knee after using. Finally, the optimization techniques included selection of the optimum dimension of polycentric knee is dependent on the data of ICR trajectory estimated from kinematic analysis of four-bar mechanism. These optimization techniques …

The prosthetic knee is one of the most important parts used in manufacturing of the above knee prostheses limb and it is considered the most important component. Accordingly, it became necessary to conduct a study and evaluate for different types a prosthetic knee. In present work, the mechanism of four bar 3R20 prosthetic knee were evaluated and studied. Virtual model of four bar 3R20 prosthetic knee joint was built using Solid Work 2018 program. The fifty parts of four bar polycentric knee were designed separately and then assembled together. The kinematic analysis of four bar polycentric knee was performed using geometric analysis and Grashof law for double rocket. The results of instant center of rotation (ICR) from analytical solution was estimated using MATLAB program. The kinetic model include data of two components of forces and joint moments which used for transfemoral amputee with (age, height …