Abstract: The present study is to assess the accuracy of the few computational models based on various shear deformation theories in predicting the static and dynamic behaviour of antisymmetric angle-ply laminated composite plates. In the present investigation two higher order refined computational models incorporate the laminate deformations which account for the effects of both transverse shear and normal deformation and a non-linear variation of in-plane displacements are used. In addition to above, few higher order models and the first order model developed by other investigators and available in the literature are also considered for the evaluation. The equations of equilibrium are obtained using Principle of Minimum Potential Energy and the equations of motion using Hamilton’s principle. Solutions are obtained in closed-form using Navier’s solution technique. The solutions of the static analysis are obtained by solving the boundary value problem and the natural frequencies are obtained by solving the eigenvalue problem. The accuracy of the solutions obtained from the different models are established by comparing the results with the solutions wherever available in the literature. Results generated independently using the various models are presented for antisymmetric angle ply composite plates which will serve as benchmark solutions for future investigations.
Abstract: In this paper, buckling analysis of functionally graded super-elliptical plates is investigated by pb-2 Ritz method. The governing equation is derived based on classical plate theory (CLP). Since closed form solution of buckling differential equation is not available under various boundary conditions, pb-2 Ritz method (energy method) is applied to calculate non-dimensional buckling load. Total potential energy is given as summation of strain energy and work done by applied in-plane compression load. In order to obtain the buckling load, pb-2 Ritz method is applied corresponding to different peripheral supports (Clamped and Simply Supported) are used in the present study. The plates are assumed to have isotropic, two-constituent material distribution through the thickness and the modulus of elasticity of the plate is assumed to vary according to a power-law distribution in terms of the volume fractions of the constituents. Variation of buckling non-dimensional parameter is considered with respect to various powers of super–elliptic, FGM power law index and aspect ratio.
Abstract: Rollover crashes can be the most dangerous vehicular crashes among all crash types which have a higher fatality rate than other kinds of crashes. The orthogonal design was adopted to evaluate structure parameters how to affect the vehicle rollover crashworthiness in dolly and curb-trip tests. It is simulated with a finite element model of SUV, which has been developed previously. The parameters are based on maximum vertical roof deforming velocity, maximum vertical deformation and lateral roof deformation which nearby occupant head. They have been selected as dependent variables or responses which reflect roof stiffness and roof crush magnitude respectively. There are 11 structure factors which have an effect on the vehicle rollover crashworthiness. It can be determined under the location of crash zone in rollover. Those factors have significant effects to the vertical roof deformation, lateral roof deformation and vertical roof deforming velocity. The result can be obtained from a series of the analysis. The main effects are compared with those factors to vertical and lateral roof deformation in dolly and curb-trip tests.
Abstract: This research emphasizes on the study of Vortex transmitter and Differential Pressure (DP) transmitter performance for a laboratory pilot plant by observing process response criteria consisting of dead-time (TD), rise time (TR), overshoot (%OS) and settling time (TS) for set point changes in a Proportional-Integral-Derivative (PID) flow control architecture. Four experiments were conducted; rising set point for Vortex transmitter, rising set point for DP transmitter, falling set point for Vortex transmitter and falling set point for DP transmitter. Limit tolerance test for Vortex transmitter and DP transmitter were done to determine the operational limits. Continuous Cycling Method is applied for controller tuning. Control and data collection for the flow plant is done using Distributed Control System (DCS) in real time. It is observed that Vortex transmitter produces a smaller TD, TS, Ts and %OS compared to DP transmitter for falling SP experiment, while less conclusive results were obtained for rising SP set up where Vortex transmitter produces a larger TD and Ts but smaller TR and %OS.
Abstract: The alternate method for evaluating the thermo mechanical process has been developed. Small attention has been paid to the mechanism of plastic deformation especially plane strain analysis. Modified the specimen geometry and using uniaxial tensile test was done to view the process. Experimental results show that the forming limit diagram as one of the formability characteristic can be view the plane strain condition that present on the thermo mechanical process. The microstructure result shows that there is a similar grain structure between hot tensile test and hot rolling results as one of thermo mechanical process method. It was concluded that the uniaxial test using universal testing machine could be done to evaluate the thermo mechanical process.
Abstract: Directional control valve is the main part in hydraulic system which has complex construction, such as moving spool to control the direction of actuator for required speed. Utilizing MR fluid properties, direct interface can be realized between magnetic field and fluid power without the need for moving parts like spool in directional control valves. This paper dedicates the experimental test of four ways, three position MR directional control valve. The experimental methods were done by connecting the MR directional control valve with hydraulic actuators. The experiment was conducted to show the principle work of the valve functionally and performance test for valve was done. The valve works proportionally to control the direction and speed of hydraulic actuators. As a result, the experimental result demonstrates the operation of MR directional control valve using two configurations. The experimental about ON-OFF and proportional operations is discussed. The MR directional control valve can replace many types of the spool directional control valve for controlling hydraulic actuator.
Abstract: In this paper, we mainly make use of path connectedness in topology to study how to set movement route of cars in F1 Racing, such that cars can change their direction effectively and safely and avoid colliding with each other. In particular, we consider the change of speed and direction after the change of position when the cars drive on linear,Y-shaped and circular routes.
Abstract: Flow induced corrosion due to the presence of turbulent flow often occurs which causes severe internal thinning and promotes premature leakage. In practice, the common method for controlling such internal high corrosion rate is chemical injection using corrosion inhibitor such as amine based which utilizing adsorption or film forming mechanism. Unfortunately, the protection performance of such inhibitor might be less effective due to turbulent flow induced. The aim of this work is to study the use of mixture of piper betle and green tea as an alternative of green corrosion inhibitor (eco-friendly) to reduce the corrosion rate of API X-52 steel in aerated 3.5 % NaCl solution in turbulent flow condition whether high inhibitor efficiency can be achieved. The method of corrosion rate measurements was conducted using electrochemical polarization equipped with CMS100-Gamry Instruments and DC105 software as well as Rotating Cylinder Electrode (RCE) simulation. The mechanism of inhibition was also investigated using Electrochemical Impedance Spectroscopy (EIS) method with EIS300 software. The results showed that the addition of mixture of 1000 ppm piper betle and 4000 ppm green tea extracts with Reynold number ranging from 0 up to 30000 reduced the corrosion rates significantly with its approximately 90 % inhibitor efficiencies achieved. In addition, EIS spectra showed that in the absence of corrosion inhibitor, the Warburg impedance (diffusion controlled) was significantly attributed to the overall impedance but in the presence of corrosion inhibitor, capacitive impedance (charge transfer controlled) was mainly attributed to the overall impedance.
Abstract: This paper presents an integrated experimental study of the thermal comfort in a Closed Air Conditioned ICT Laboratory at Ungku Omar Polytechnic, Malaysia. The aim of this study is to determine the level of thermal comfort in the ICT laboratory by using the Thermal Confort Measurement (TCM) equipment. The ICT laboratory is considered as an indoor environment and this study had been carried out by the use of the custom made TCM from 8.30 am till 4.30 pm. This TCM is able to investigate the level of thermal in this laboratory in aspects of the level of carbon dioxide (CO2), humidity, wind speed, ambient temperature, and globe temperature simultaneously. All the data were then compared to the standards or guidelines produced by National Institue Of Safety and Health of Malaysia (NIOSH), American Conference of Governmental Industrial Hygienists (ACGIH) and the American Standards of Heating Refrigeration and Air Conditioning Engineers (ASHRAE 55), which is currently being practiced in Malaysia. From the study that was carried out it was revealed that the level of CO2 in the ICT Laboratory exceeded the hazardous level thus can produce the negative impact to the productivity of the end user which are the student that will be using this laboratory.
Abstract: In most mega cities roadside barriers are used to protect receivers from noise pollution during recent years. Median noise barriers, like roadside noise barriers, can be employed to reduce the impact of traffic on roadside communities. In this study, a 2D boundary element method (BEM) is used to predict the insertion loss of different barrier models. It was shown that the performance of a median barrier along with a roadside barrier is affected if another road side barrier will be erected. However, it is possible to apply some new barrier designs to decline the negative effect of the extra roadside barrier. The best shape for inclined median barriers when erected inside parallel barriers was seen to be the tilted designed with 10 degrees slope.