Dynamic Analysis of UAV’s Motor Support Bar Length Control System

UAV (Unmanned Aerial Vehicle) can be described as aircraft that do not need any presence of pilots inside it. Basically, UAV is come out in a small aircraft sothat the aircraft can be easily controlled by the people from afar[1]. The UAV’s motor support bar length control systems are the UAV’s control systems that move according to the variable arm length movement and also a constant revolution of the propeller speeds. The purpose of the study is to run the dynamic analysis at the UAV’s motor support bar length control systems and also to enhance the UAV’s mathematical modellingby using the SOLIDWORKS®software which involved in using both CAD and CAE systems[2]. The detaileddesign is used SOLIDWORKS®software to conduct the static and dynamic analysis of UAV’s motor support bar length control systems. The design is restricted to the arm due to the critical part that has the highest vibration at the UAV’s motor support bar length control systems. The results that obtain from the study from the static and dynamic analysis are the displacement of the motor, Von Misses stress of the arm, and also the resonance frequency that will give the modes shape to the systems

Effect of thermal ageing on the scratch resistance of natural-fibre-reinforced epoxy composites

In this study, the effects of thermal ageing on the scratch‐resistance properties of natural‐fibre‐reinforced epoxy composites were investigated. Jute, kenaf and hemp‐fibre‐reinforced epoxy composites were fabricated using the vacuum infusion method. The natural‐fibre‐reinforced composites were exposed to thermal ageing for 7, 15, and 30 d at 90 °C temperature. Scratch tests were carried out using a CSM Revetest Xpress machine. The scratch resistance properties, such as the critical normal load, coefficient of friction, penetration depth, fracture toughness, scratch hardness, and scratch tearing were determined after thermal ageing. The results demonstrate that the scratch resistance of the composites decreased as the thermal ageing time increased. However, the jute‐fibre‐reinforced epoxy composites had the highest critical normal load, fracture toughness and scratch hardness compared to those of kenaf and hemp‐fibre‐reinforced epoxy composites after 30 d of thermal ageing

Temperature distribution analysis of lithium-ion polymer battery surface

The main objective of this study is to investigate the heat load generated by the Lithium-ion (Li-ion) battery during the completion of the cycle. Besides that, the objective is also to identify the most affected surface of the Li-ion battery towards the temperature during the charging and discharging process. An experiment is carried out for five different conditions of battery to obtain the data for heat load calculation purposes. The five conditions are differences in discharge ampere. From the result obtained there are differences in heat load generated by the battery during the charging and discharging process for every condition. Furthermore, the greater the discharge ampere, the lower the time taken for the battery to discharge and the higher the heat load generated by the battery. Besides that, an experiment to investigate the temperature distribution along the experiment is also carried out. Four surfaces of battery (front, right, left, back in vertical position of battery) are put into concern in obtaining the temperature distribution. Every surface gives a different temperature distribution during the experiment. Surface 4 recorded the highest average temperature distribution. Thus, the cooling system will consider the cooling capacity at this surface

Effects of pebax coating concentrations on co2/ch4 separation of rgo/zif-8 pes membranes

The biggest challenge surrounding application of polymeric membranes for gas separation is their trade–off between gas permeation and selectivity. Therefore, the use of mixed matrix membranes (MMMs) comprising inorganic materials embedded into a polymer matrix can overcome this issue. In this work, PES flat sheet membrane and MMMs consists of 10 wt.% of rGO/ZIF-8 hybrid nanofillers were fabricated via dry/wet phase inversion process. Dip‐coating technique was then used to deposit PEBAX selective layer onto the surface of rGO/ZIF-8 PES support. The effects of PEBAX coating solution concentrations (2, 3 and 4 wt.%) on the permselectivity of CO2 and CH4 were investigated. The as-prepared rGO/ZIF-8 nanofillers and MMMs were characterized by fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (SEM) prior to gas separation performance study. Gas permeation testing was carried out at operating pressure of 1, 3 and 5 bar using CO2 and CH4 gasses. It was observed that the prepared PES membranes and rGO/ZIF-8 PES MMMs did not have any selectivity towards the gases although their permeability was high. As the concentration of PEBAX coating solution increased, thicker coating layer was formed. Therefore, the permeability of CO2 rapidly dropped but the CO2/CH4 selectivity increased significantly up to 38.4. Results indicated that the use of 2 wt.% of PEBAX was not effective to form homogenous coating layers on PES membrane and to cover any defects on membrane surfaces, thus, possessing low selectivity of CO2/CH4. The high gas separation performances obtained in this work was due to the synergistic effect rGO and ZIF-8 crystals. In the rGO/ZIF-8 MMMs, the dispersibility are enhanced due to the presence of distorted rGO sheets, while the ZIF-8 component ensure the porosity of the nanofillers and permit gas interactions with the metallic sites and functional groups on the organic linker. These sites facilitate the reactive adsorption leading to enhanced CO2 adsorption as compared to CH4

Microwave dielectric analysis on adhesive disbond in acrylic glass (poly (methyl methacrylate)) at Ku-band

A microwave dielectric spectroscopy for detecting adhesive disbonds between acrylic glass (aka Poly (methyl methacrylate)) was discussed. The adhesive bond was developed using epoxy resin and acrylate. The level of joint disbond can be quantified using Young Modulus. In this work, the strength of bond is affected by radius of air void within adhesive bond. A high-frequency electromagnetic wave propagated through two joint acrylic glass with acrylate and epoxy adhesive using waveguide adaptor WR90 in conjunction with professional network analyser. This electromagnetic wave is reflected and transmitted at the bond interface due to mismatch impedance at adhesive bond. The output is a dielectric properties that characterizes the bond interface. The increment of Young Modulus leads to increment of dielectric constant and loss factor for epoxy resin and acrylates, respectively