Abstract: Nowadays, the interest in using natural fibers reinforced plastic have been increased dramatically in many engineering applications due to its distinctive properties such as low density, good Energy-absorbing capacity, and is considered environmentally friendly. In the present paper investigated experimentally the crashworthiness characteristics and corresponding energy-absorbing capability of different geometrical shapes under quasi-static loading of natural tubular jute mat/epoxy composite structures. The purpose is to determine the appropriate design of natural compounds, which can provide the potential to substitute conventional structures currently in use. Two different geometrical shapes (corrugated and circular tubes) were fabricated by a combination manual lay-up and vacuum-bagging moulding techniques, specimen thickness (2, 3 and 4 laminate plies), tulip triggering and 100mm in length, and then the post-curing has been conducted on graded temperature treatment. The influence of cross-section shape, number of laminate plies, and temperature treatment on crashworthiness characteristics under quasi-static loading were examined and discussed. From this unique study, Laboratory results indicate that most of the specimens failed in a stable and progressive manner. However, the corrugated cross-sectional shapes with three layers are considered optimum design in terms of energy-absorbing, peak load, average load, and crushing efficiency for crashworthiness tubes application.

Abstract: To predict the reliability of a product or a system, life data from a representative sample of the system performance is fitted to the suitable statistical distribution. Reliability analysis techniques have been accepted as standard tools for the planning, design, operation, and maintenance of thermal power plants. Therefore, the parameterized distribution can be used to estimate important life characteristics such as reliability, or probability of failure at a given time, mean life, and failure rate. In today’s competitive environment reliability analysis is the most important requirement of almost all types of systems, subsystems, and complex systems; whether they are mechanical, electrical, or electronic devices. To alleviate failures and improve the performance and increase the operational life of these components and systems, key performance indicators such as: Failure Rate, Reliability, Availability, and Maintainabilityare investigated.Weibull++/ALTA is used to fit the available data set concerning three sets of gas turbines (GT) operating in a power plant to estimate the probability density function (PDF), plant reliability, and failure rate of each set and for the whole plant. In this study data of a gas turbines (GT) power plant (three groups of GTs) is used. Two methods for parameter estimation are applied in the data fitting stage: Maximum Likelihood (MLE) and Rank Regression Analysis X –axis (RRX). Using Mean Time Between Failure (MTBF) data, the results show that the system overall reliability is 97% at 413 hr while using Down Time (DT) data the system reaches the same reliability at 289 hr. Also at 800 hr, the reliability of Group-1 is 74% while the reliability of Group-2 and Group-3 is 83% and 45% respectively. Downtime losses and cost of maintenance of the power plant can be minimized by implementing a proper mix of maintenance and repair approaches on system reliability failure rate.

Abstract: The transport of goods has been widely studied due to the importance to guarantee final product quality. The case of particulate materials is even more complicated when companies decide to innovate in the product's shape, because of the trade-off between packaging and cargo space optimization. That is the case of compressed hygroscopic particulate material, which may be addressed by compacting particles in geometric forms to improve end-user experience. However, there is a problem when transported materials are compacted particles: cracks and product damage may occur during transportation if conditions of the truck such as vehicle suspension or road conditions aren't met. These kinds of problems can be simulated to influence design decisions related to vehicle and product specifications to avoid them. This document proposes a crack identification method applied to hygroscopic particulate compressed materials subject to simulated transport conditions. An experimental approach is used to simulate package and transport conditions. Spectral analysis was used to determine if a material fulfills transport requirements to go from a given location to its destination, in terms of cracking. The article describes the experiment, data acquisition (hardware and software), as well as the theoretical basis of spectral analysis used for data processing. Finally, results are presented to explain how this analysis is capable of predicting if such a material will be damaged during transportation. The experiment considers the set of frequencies that affect the product in terms of transportation methods, compacting techniques, and packaging design.

Abstract: This paper introduces a hybrid control model, which is based on the Model-Driven Architecture (MDA) approach combined with the real-time Unified Modeling Language (UML), Extended Kalman Filter (EKF) algorithm and hybrid automata, in order to conveniently deploy controllers of micro Unmanned Aerial Vehicles (UAVs) such as the Quadrotor UAV (Q-UAV). This model also creates a capsule-based collaboration pattern, which can permit the designed control components to be customizable and reusable in new application developments of various UAV typed Vertical Take Off and Landing (VTOL). The paper brings out stepwise the dynamics and control architecture of a Q-UAV for control inputs that are then combined with the specialization of MDA features as follows: the Computation Independent Model (CIM) is defined by the specification of use-case model together with the EKF algorithm and hybrid automata to define the implementation analysis for control; the Platform Independent Model (PIM) is then designed by specializing the real-time UML features including main control capsules that depicts in detail structures and behaviors of the controller; the detailed PIM is subsequently transformed into the Platform Specific Model (PSM) by object-oriented open-source platforms to rapidly deploy the Q-UAV controller. Based on this proposed model, a trajectory-tracking controller was developed and tested that permits a Q-UAV to reach and follow the desired reference trajectory.

Abstract: Large amount of polymer waste produced from the Fused Deposition Modeling (FDM) process because of the failed part, the structure of support, human error and machine failure. Thus, there needs for recycling. However, after the polymer is recycled, its mechanical properties deteriorate due to the interlayer bonding strength become weaker. This study investigated the improvement of mechanical properties for recycled Acrylonitrile Butadiene Styrene (ABS) by the assisted ultrasonic vibration. A piezoelectric transducer was mounted on the printer platform to provide the ultrasonic vibration at different frequencies while printing of the recycled ABS specimen commences. The frequency of vibration was set at 0 kHz, 10 kHz and 20 kHz respectively. The specimen orientation was set at the edge, flat and upright (X, Y and Z). Microstructure analysis and tensile test were performed to investigate the mechanical properties of recycled ABS specimens. The results showed that ultrasonic vibration-assisted FDM was able to reduce the amount and size of the voids and porosities. In addition, the ultimate tensile strength (UTS) improved in the range of 11.03% to 67.61%; strain improved in the range of 1.30% to 45.83 %; Modulus of Elasticity (MOE) improved in the range of 15.24 % to 24.10 %. The study indicates the mechanical properties of recycled ABS can be enhanced with the application of ultrasonic vibration-assisted FDM.

Abstract: Fused deposition modeling is a three-dimensional (3D) printing technology that usually performed with molten thermoplastic in a heated liquefied nozzle and deposited layer by layer on the printing platform. To reduce the usage of material and printing time via fused deposition modeling technology, a user typically specifies infill pattern and density. Nevertheless, it is crucial to know how these parameters affect the mechanical properties of the printed object. This study aims to investigate the tensile properties of polylactic acid 3D-printed specimens with different infill patterns and infill densities. Three infill patterns: linear, diamond, and hexagonal, with three infill densities: 25%, 50%, and 75%, were assessed. The specified infill patterns and densities were generated using slicing software MakerBot Makerware. A series of test specimens (ASTM D638 Type-I) with different infill patterns and densities were produced using the Flashforge Creator 3D printer. Tensile testing was conducted by using the mechanical testing machine according to ASTM D638. The results showed that the tensile strength and elastic modulus improve as the infill density increases for all examined infill patterns. The combination of 75% infill density and linear pattern depicts the highest tensile strength (42.67 MPa) and elastic modulus (1222.78 MPa). This combination (linear 75%) was the ideal infill pattern and density which have substantial strength, great stiffness, and less printing cost. The obtained data can be used as a reference for FDM 3D printer users in designing and manufacturing 3D printed objects.

Abstract: Natural frequency of any natural or artificial material play a role in selection it for industrial and manufacturing applications. Natural frequency for material meaning its ability to absorb external vibration for avoiding resonance. In the presented paper wood and steel will used as a type of natural materials, concrete also will used but as an artificial material. Calculation of natural frequency for each material will done with same volume of structure. Natural properties of wood show superiority for many mechanical applications. The aim of this study is to investigate the effects of various factors including characteristics of wood, steel and concrete on their natural frequencies with the aim of producing recommendations to promote sustainability. Fuzzy logic control system also implemented for optimizing the impacts of these characteristics on the structure’ vibration. In addition, the natural frequencies of structures have been assessed against the wind, earthquakes, and traffic vibrations. The results reveal that for the same dimensions of the structure, wood shows the highest natural frequency, steel followed by concrete. Results indicate that wood can complement natural properties of a range of industrial manufacturing materials to promote sustainability and improve performance. This can have implications for heavy machines laboratories (like foundation for that machines) and other engineering applications.

Abstract: Due to the surface texture and dimensional accuracy comes to be extremely necessary for the designer or producer of machine tools, along with the user. The main objective of this work is to investigate the influence of a number of passes and machining cutting conditions on the surface texture of commercially pure copper produced by the ECAP process. In this research, the X-ray diffraction (XRD) test will be used for examining the structure of the pure copper sample and the produced samples by the ECAP process. Also, the features of the microstructure of the original sample and the ECAP samples will be investigated by utilizing the scanning electron microscopy (SEM). Then, the surface texture of the machined samples will be studied by using a 3D optical microscope and SEM device at different machining cutting conditions. Finally, the experimental results are displayed that the increase in the number of the ECAP passes had much affected the surface topography of the machined sample.

Abstract: A hybrid ground aerial robot (HGAR) has been developed to combine both capabilities of aerial robots and ground mobile robots to overcome the limitations of each single type. This research introduces a new securing mechanism and improves also the propeller-thruster transformation mechanism for the HGAR. The securing mechanism is designed to be light and to give high stability, and low power consumption for both flying and ground motion modes. In the developed transformation mechanism, the robot uses the propellers which are already installed for the aerial mission as actuators to transform between the flight and ground-motion configurations. In contrast to the previous design, no need here to additional position controller to avoid propellers’ collision or springs to start the switch to the ground configuration. The propellers are controlled by the Feedback-Linearization which is combined with Robust-Internal Compensator to achieve the controller robustness. The HGAR is virtually built and dynamically modeled using ADAMS® software then connected with MATLAB/Simulink® to test the proposed mechanisms and the proposed controller. The results indicate a satisfactory performance of the proposed mechanisms and controller.

Abstract: This paper presents a robust dynamic sliding mode control using an adaptive disturbance observer for unmanned aerial vehicles (UAVs) through a general procedure of designing the controller for a second-order nonlinear system. The algorithm is applied to eliminate undesirable effects of disturbances/ uncertainties for improving the tracking performance of attitude and altitude control of UAVs. The concept of the proposed method consists of two stages. First, an adaptive disturbance observer is developed to estimate unknown disturbances/ uncertainties. Second, a robust dynamic sliding mode controller based on a combination of the Proportional–Integral–Derivative (PID) sliding surface and Super Twisting sliding mode techniques strongly alleviating the chattering phenomenon, is proposed to compensate for the effect of perturbations on the control system. In addition, the stability of a system is achieved by the Lyapunov theory. A numerical simulation was performed and compared to recent methods to demonstrate the robustness and effectiveness of the proposed algorithm.