RMUTL Engineering Journal

Comparison of Water Levels By Sobel Fringe Method and First Order Differential Equations

2023-08-18T08:43:48+07:00

This research is to determine the edge of the camera image using a model to create a water barrier. CCTV images were analyzed as color images and transformed to find the edge of the image by two methods: Sobel method and first-order derivative method. The number of images to be analyzed was 1000 frames and analyzed 1:1 frames for greater resolution and accuracy, then compared with MSE, RMSE and MAD. The results showed that the first order derivative method was the most detailed and accurate with an MSE of 13.968 %, RMSE of 1.18 and MAD of 0.491 compared to Sobel method with an MSE of 919.01. %RMSE of 9.586% and MAD of 8.645.

Large Displacement Analysis of Toroidal Dome Structures Having Variable Thickness under External Pressure

2023-07-12T13:56:06+07:00

This paper presents a large displacement analysis of a toroidal dome structure having variable thickness under external pressure using differential geometry. Membrane and flexural strain energies are defined in terms of metric tensor and curvature components. The energy functional of the toroidal dome structure under external pressure is derived from the principle of virtual work, and it is expressed in the appropriate forms. Numerical results can be obtained by finite element method and iterative procedure. In this study, finite element model is simulated using one-dimensional beam elements via a fifth-order polynomial shape function, and it is divided along the meridian line. The numerical results indicate that the displacement responses of the toroidal dome structure increase for larger external pressure. The surface of the toroidal dome structure increases for a large value of the cross-sectional bend radii ratio. Then the displacement responses increase under a large value of the cross-sectional bend radii ratio. In addition, the stiffness of the toroidal dome structure decreases if the cross-sectional radius-to-wall thickness ratios increase. Therefore, the displacement responses increase under a large value of the cross-sectional radius to wall thickness ratio.

Unmanned Aerial Vehicle Surveying for Roads Construction and Maintenance

2023-09-11T09:25:16+07:00

This article studies the application of unmanned aerial vehicles (UAVs) for measuring earthwork volume by using the surface-to-surface method. It compares embankment volume between total station survey and UAV. The aerial photographs are controlled using Ground Control Points (GCPs), with a total of 5 points. The GCPs are measured using a Global Navigation Satellite System (GNSS) receiver in a Network Real-Time Kinematic (RTK) system. The study area is a local road in Lampang Province. The flying heights were 131 meters above the terrain with total of 35 images at average ground sampling distance (GSD) about 3.60 cm per pixel. Frontal and side overlap settings were at 85% and 75% respectively. The positional accuracy of the aerial photographs acquired by the UAV is compared to the check points, and the displacements in the X, Y, and Z axes are found to be 6.787 4.023 and 5.048 cm. respectively. The horizontal and vertical positional accuracies are evaluated against the ASPRS standards. The horizontal accuracy is within the class 12.5 cm, and the vertical accuracy is within the class 20 cm for vegetated areas. The earth volume calculation is performed using the Earthwork Reports method, employing the Surface-to-Surface calculation approach. The calculated earth volumes from the surveying camera and aerial photographs are determined to be 620.5 cu.m. and 570.7 cu.m. respectively, resulting in a difference of 49.8 cubic meters or approximately 8%. This study shows the application of unmanned aerial vehicles and GNSS-Based DEMs for evaluating earthwork volume which can be applied road construction and maintenance works.

Effect of the Angle between Steel Fiber Orientation and Failure Plane on Compressive and Flexural Strengths of Self-Compacting Mortars

2023-07-24T06:45:06+07:00

This paper presents effects of the angle between steel fiber orientation and failure plane (q_f) on compressive strength and flexural strength of self-compacting mortar. Mortar proportions contained water to cement ratio of 35% and 45% with sand to mortar ratio of 40%, 45% and 50%. Fiber quantity of 0.8% and 1.6% by volume of mortar are compared and the influence of the angle between steel fiber orientation and failure plane (q_f) of 0°, 30°, 45°, and 90° is studied. Research results showed that the compressive strength increased approximately 20% by increasing fiber amount of 0.8%, but it was found that the compressive strength reduced with the increase of steel fiber to 1.6%. The angle between steel fiber orientation and failure plane (q_f) at 30° and 45°. affected in an increase in flexural strength by an average of 50%-70% when compared to the q_f of 0°. However, it was found that the compressive strength decreased from the highest value by approximately 20%-30% with the q_f of 90°. The most efficient reinforcing steel fiber in self-compacting mortar requires a consideration of fiber content, fiber orientation, and failure plane.

Design and fabrication of torsion testing machine for reinforced foam concrete

2023-07-01T14:29:06+07:00

The objective of this research was to design and fabricate a torsion testing machine. Recently, there have been more applications of composite concrete materials for torsion. The torsion testing machine used the principle of torque from the motor with a gear ratio-reduced speed, which was then transmitted to the chain. The load cell was used to measure the force generated by the chain's tension. During calibration, the standard workpiece properties were compared to the experimental data of the new torsion testing machine, and the results showed that they were acceptable. From the experiments, the torsion resistance values of all three pieces were in the range of 75-100 N·m, and they would break apart after the twisting angle exceeded 35 degrees. In the case of reinforced foam concrete, cracks were observed to appear along the axial direction, confirming torsion. The average torsional resistance of reinforced foam concrete, calculated using formulas that adjusted the densities to approximately 600, 700, and 800 kg/m3, were found to be 13.05, 22.67, and 31.87 N·m, respectively. Furthermore, these findings can be helpful in determining the torsional resistance properties of other materials, such as fiber-concrete and wood-concrete.

Application of Quality Function Deployment Techniques with Kansei Engineering for the Design and Development of Bags in the Lygodium

2023-07-13T11:09:23+07:00

This research aims to develop and design the Lygodium wallet product by using of quality function deployment techniques with Kansei Engineering. Exploring and converting customer needs into product purchase decisions. The results were analyzed using the qualitative functional transformations in the product planning matrix. It focuses on converting customer requirements into technical specifications. Kansei Engineering is therefore used to support further analysis of product design that conveys the emotions of the customer, which is an important part of product development. The results showed that product development in the qualitative functional conversion analysis section has changed from material, usability, quality, convenience, and cost. In the first quantitative analysis section of Kansei Engineering has been changed product characteristics. The number 6 product features, namely size, style, style of bag, usage, color tone, and shape have been changed to make the product design that conveys creative emotions, simplicity, and outstanding interest. Therefore, for the development and design of Lygodium wallets, it was found that the customers were most satisfied with the characteristics of the weaving method as the priority. The level of satisfaction was at a very good level (Average= 4.50), along with the satisfaction of feeling simple. The satisfaction level was very good (Average = 4.51).

Application of Data from GNSS Continuously Operating Reference Station for Monitoring the Mine Wall in Padaeng Mine Tak

2023-03-10T17:35:59+07:00

Continuously operating reference station is a station established for the immediate reception and transmission of satellite data to the control stations as part of the network RTK in Thailand for Cadastral Surveying created by the Department of Lands. In this research, the satellite signal data from the continuously operating reference station is compiled as a reference station for checking the wall movement of Pha Daeng mine in Tak province by using rapid static survey. There are three steps to testing. The first step is testing for a suitable continuously operating reference station for the Pha Daeng mine area. It was found that Mae Sot Station in Tak Province was the most suitable. The second step is testing the accuracy of the coordinates by using the coordinates obtained from the GNSS survey to compare them with the coordinates obtained from the total station. It was found that the accuracy of the average horizontal and vertical coordinates was ±0.020 meters and ±0.040 meters, respectively. The third step is testing for the displacement of the walls of Pha Daeng mine by specifying 12 test points covering the area prone to displacement. It was found that the walls of Pha Daeng mine had less movement, with the horizontal rating of no more than 0.002 meters and the vertical rating of no more than 0.003 meters.

Remote water supply control simulation system via SMS

2023-05-31T09:00:38+07:00

This article presents to build remote water supply control simulation system via SMS suitable for water supply work remotely to help support the development of a modern water supply system to be effective and to speed up opening and closing of water supply system each time. The system adopted Arduino technology, Module Sim 900 and PLC to apply in the off-open water supply remote. In order to control the work of the water supply system to be effective, it is designed as a replica by design. There are 2 main sections: the first part is the SMS receiver in the main water supply, and the second part is sending SMS in the reservoir. When receiving an SMS message "L" the main water supply will open water to the reservoir and when receiving an SMS message "H" water supply system will stop open water immediately. From the design, it takes time to send "L" about 7.55 seconds when the pond has low water level and sending "H" about 7.35 seconds when the reservoir water level is high and the main plumbing will take about 3.79 seconds to open the system and takes about 3.68 seconds off when receiving an SMS message.