Journal of Applied Engineering Science

ANALYZING THE EFFECTS OF MANUFACTURING PARAMETERS MODIFICATION ON FINAL SURFACE ROUGHNESS IN SELECTIVE LASER MELTING PARTS

M. P. Calvo Correa, Carlos Julio Cortés Rodriguez — Mon, 02 Dec 2024 00:00:00 +0100

Selective Laser Melting (SLM) is an additive manufacturing technique widely used today for producing metal components. This method enables the fabrication of geometrically complex parts while reducing costs and production time compared to traditional manufacturing techniques. However, a notable drawback of SLM is its tendency to produce high surface roughness and superficial defects such as balling, porosity, debris, and waviness. This study evaluates the effects of modifying two manufacturing parameters—scanning speed and laser power—on the final surface roughness. To achieve this, cylindrical specimens were fabricated using various combinations of these parameters, and the resulting surface roughness metrics (Sa, Sq, Ssk, Sku, Sdr, among others) were measured using an optical 3D surface roughness measurement instrument. A Taguchi L8 design was applied to analyse the influence of the manufacturing parameters on the measured roughness characteristics. This study investigates the influence of laser power and scanning speed on surfaces manufactured through Selective Laser Melting (SLM) and their effects on the previously described roughness parameters. The authors observed that the manufacturing parameters have varying impacts on the final surface roughness of components produced via SLM. Due to the inherent characteristics of the process, a specific combination of parameters that reduces roughness within a specimen's layer may increase roughness at the layer boundaries. These findings underscore the complex relationship between manufacturing parameters and surface roughness in SLM-produced parts, emphasizing the need for strategies, such as surface finishing post-treatments, to achieve the desired surface quality.

PLASTIC BLOCK FOR BUILDING CONSTRUCTION MATERIAL

I Nyoman Arya Thanaya, I N. Karnata Mataram, Muhammad Fathan — Fri, 15 Nov 2024 00:00:00 +0100

Plastic wrap waste increase from time to time. Efforts are needed to utilize them as they are less demanded for recycling by the private sectors in Bali and Indonesia. This paper describe effort to use combination of waste thin plastic wrap as plastic block for wall construction material. The plastic wrap wastes were cut into 5-10 mm size, then they were melted in a hot waste engine oil at 200°C. The mixture was then poured into a metal mold, slightly cooled down and compressed using a compression machine. The mixtures produced was without and with added rice husk ash as filling material. The size of the plastic block was 20×10×8cm. It was found that the densities of the samples were less than 1gram/cm³, the compressive strength can achieve 25kg/cm², the Porosities were low, ranges from 0.220-0.290%, the Initial Rate of Suctions (IRS) were very low ranges form 0.0004-0.00075 kg/m2.minute, and the and water absorptions were also low (0.02-0.03) %. In general, the compressive strengths were comparable to low quality bricks commonly produced.

INNOVATIVE AIRSHIP DESIGN FOR REAL-TIME AIR QUALITY MONITORING USING IOT TECHNOLOGY

Fri, 15 Nov 2024 00:00:00 +0100

The effect of poor air quality on human health has been linked to both short-term and long-term exposure to air pollutants. One of the most important steps in reducing emissions is accurate identification of these pollutants. This can be achieved by using Internet of Things equipped remotely operated airships that can survey large areas and gather pollution data. The ability of an airship to function at low altitudes for extended periods is the main design requirement of airships. This study describes a methodology for conceptualizing and building a helium-filled blimp for remote measurement of atmospheric pollutants (Carbon monoxide, Carbon dioxide, and Sulphur dioxide), temperature, and pressure. An onboard telemetry system measures the data while the airship is in flight and transmits them in real time to a ground-based station. The experiment showed that remotely operated airships are capable of gathering air data and their quality, enabling environmental scientists and regulatory agencies to better understand the behaviour of air pollutants and take steps to mitigate them.

STRENGTH STUDY OF MACHINE TOOL BEDS WITH CURVILINEAR STIFFENERS FROM POLYMER CONCRETE

Tue, 26 Nov 2024 00:00:00 +0100

This study addresses enhancing the strength of metal-cutting machine tool beds made from polymer concrete by optimizing the internal cross-section design through spiral stiffeners. Key factors influencing the bed’s strength include the composite preparation technology, the mixing speed (600 - 800 rpm), and duration (3 - 4 minutes). A strong correlation exists between spiral pitch, mixing speed, mixing time, and the bed’s strength.

CFD INVESTIGATION OF THE EFFECT OF MODIFIED TWISTED TAPE ON HYDROTHERMAL ENHANCEMENT IN VERTICAL PIPE

Fawzi Sh. Alnasur, Riyadh S. Alturaihi — Mon, 16 Dec 2024 00:00:00 +0100

Heat transfer enhancement has been a significant focus in hydrothermal engineering for several decades. The current paper represents an investigation using computational fluid dynamics (CFD) for a vertical circular tube having twisted taper inserted (plain and modified) with different twisted tape ratios TR, i.e., 7.8, 3.9, and 2.6, at three uniform wall heat fluxes and ranges of Reynolds number as boundary conditions. The twisted strips were used as a system to produce a turbulent, powerful swirl flow with an increase in the intensity of the secondary flow at the radial direction of the tube. The (friction facto) f and (Nusselt number) Nu were two measures of pressure loss and heat transfer variation that have been studied and graphically depicted. So, to balance the heat transfer enhancement quantity with pressure losses, the performance evaluation factor PEF was tested. It was observed that the twisted tape insert enhances the radial secondary flow intensity. The findings demonstrated that, in every scenario, the increase in(Reynold number)Re at the inlet, heat flux quantity, and twisted ratio results from a proportionate increase in heat transfer. At the same time, the friction factor decreases with an increase in all boundary conditions, except the twisted ratio, where the friction factor increases with increasing heat transfer. After accounting for heat transfer and friction coefficient, it was discovered that the tube with modified twisted stripe and the twist ratio was 3.9 performs best out of all the configurations examined. The performance evaluation factor PEF of pipes inserted with modified twisted tape was higher, reaching 1.5. This study is based on enhancing a high-performance evaluation factor of heat exchangers for use in industrial settings.

ANALYZE THE PERFORMANCE OF HORNS WITH COMPLEX WORKING SURFACES USED IN ULTRASONIC WELDING OF CAR TURN SIGNALS

Ngo Nhu Khoa, Dang Anh-Tuan, Dinh-Ngoc Nguyen — Tue, 19 Nov 2024 00:00:00 +0100

Ultrasonic plastic welding technology has been widely applied in practice. Welding horn design is one of the important tasks. Many studies have presented this problem. However, most of these studies are only interested in face profiles that are flat or have symmetrical profiles. Meanwhile, ultrasonic welding horns with complex working surfaces receive little attention. This research presented the design of an ultrasonic horn with a complex working surface. Moreover, the influence of the slot width in the horn, an important design parameter, on the performance of the designed horn was considered. The finite element method was used for modal and harmonic analysis. The performance of the design was assessed through criteria that are the uniformity of amplitude, the distribution of the greatest stress at points on the working surface, and closed to the target frequency. A new parameter, namely Displacement unevenness (a), was proposed to evaluate the unevenness amplitude in the working surface of the horn. Effects of three alternative slot structures width corresponding values of 12 mm, 17 mm and 20 mm, denoted by B12, B17, and B20 respectively were carried out. The results showed that the B12 and B17 designs have natural frequencies close to the target frequency of the welding machine, while the natural frequency of the B20 design is far from the target one. The B12 and B17 designs also produce an unevenness amplitude smaller than those of the B20 design. The model showing the relationship between design parameters and the required criteria must be further developed. Additionally, this result can be said for the design guidelines not fully available in the literature.

A DEMONSTRATIVE-KINESTHETIC TEACHING APPROACH FOR INVERSE KINEMATICS OF A 4-DOF ROBOT MANIPULATOR

Griffin P. Mabong, Emmanuel A. E. Osore, Peter T. Cherop — Sun, 15 Dec 2024 00:00:00 +0100

Kinesthetic guidance as a paradigm of programming by demonstration of robot manipulators has eased the process of robot programming, especially for non-skilled and semi-skilled shop-floor operators in manufacturing industries. Today, the inverse problem remains an area of interest in robotics, leading up to the deployment of robots for collaborative technology with humans. The paper proposes using a demonstrative-kinesthetic teaching technique to program a robot manipulator, determine the inverse kinematics using the approach, and compare with structured texts to program the manipulator. The approach was carried out on a Dobot magician, a 4-DOF robot manipulator. A control platform was created using MS Visual Studio IDE, using Python to control the arm, and it was programmed demonstratively using the lock arm button and structured texts to carry out a palletizing task. The joint parameters were collected and compared using the demonstrative-kinesthetic technique and structured texts as programming methods. The structured texts were used as a control for the experiment. The results showed that joint values obtained using the demonstrative-kinesthetic technique did not vary significantly from structured texts’ joint values. The approach provided an avenue for quickly programming a robot manipulator, especially concerning the non-skilled workforce, and finding analytical solutions to the inverse problem of the robot manipulator.

PLANNING OF TRANSPORTATION OF RHEOLOGICAL COMPLEX OILS FROM VARIOUS FIELDS THROUGH AN EXTENSIVE PIPELINE SYSTEM, TAKING INTO ACCOUNT ENSURING THE SPECIFIED QUALITY OF THE DELIVERED OIL

Anvar Valeev, Radmir Tashbulatov, Chingiz Nurmukhamedov — Tue, 26 Nov 2024 00:00:00 +0100

The article discusses the problem of operating an oil pipeline system in the presence of a significant number of suppliers of rheologically complex oils with different sulfur content and a large number of oil consumers with different requirements for oil quality in terms of sulfur and other parameters. The problem of determining optimal cargo flows in such a system is discussed. A method is proposed for determining optimal cargo flows in a branched oil pipeline system, providing a global optimum in terms of minimizing energy costs for pumping. The article provides an algorithm for implementing the method using a conditional example.

CYLINDER AND PISTON: MATERIAL SELECTION IN THE DESIGN PHASE

Do Duc Trung, Nazlı Ersoy, Vo Thi Nhu Uyen — Thu, 14 Nov 2024 00:00:00 +0100

The piston and cylinder constitute an inseparable pair, playing a crucial role in both the mechanical and hydraulic industries. They are frequently employed to convert linear motion into rotational motion in various types of engines and are especially valuable for heavy-duty applications. Material selection for these components is conducted during the product design phase. This study aimed to identify the optimal material for each type of product. To determine the best material, a ranking of materials was carried out using the CoCoSo (COmbined COmpromise SOlution) method, with scores for criteria calculated using the Entropy method. Nine materials for cylinder construction were evaluated, including S355JR, S275JR, S235JR, BS97007M20, R35, R45, IS1030GRADE, AISI304, and 60-40-18. Additionally, seven materials for piston construction were considered: 332-T5, A336, 242-T5, 333.0-F, A213.0 F, AISI308, and A319.0F. The Entropy-CoCoSo approach was employed to rank the materials for each case (cylinder material and piston material). The results indicated that AISI304 is the optimal material for cylinder manufacturing, while A336 is the best material for piston manufacturing. Furthermore, the study extensively examined the impact of different weighting methods (Entropy, WENSLO, CRITIC, ROC, RS, EW) and normalization techniques (sum, vector, max, max-min, peldschus, decimal) on CoCoSo method results using an innovative sensitivity analysis approach, analyzing the techniques according to their sensitivity levels.

OPTIMIZATION OF ELECTROSPINNING PARAMETERS USING AN ARTIFICIAL NEURAL NETWORK (ANN) MODEL FOR ENHANCED NANOFIBER PRODUCTION

Mon, 16 Dec 2024 23:52:13 +0100

Electrospinning is a simple and cost-effective technique for creating nanofibers with diverse applications.Optimizing electrospinning parameters is crucial for producing nanofibers with desirable attributes, such as uniform diameter and bead-free morphology.Conventional trial-and-error strategies are frequently protracted and may not necessarily result in optimal outcomes. This investigation delineates the formulation of an artificial neural network (ANN) model specifically designed to systematically optimize electrospinning parameters. Crucial input variables, such as applied voltage, feed rate, and polymer concentration, were utilized to train the ANN model, which was constructed with multiple hidden layers to effectively encapsulate the intricate relationships between input parameters and the resultant nanofiber properties. In this research, an ANN was devised with a 4-3-1 architecture that was trained on a dataset extrapolated from experimental data documented in prior literature and employed the Levenberg-Marquardt algorithm to ascertain robust performance. Upon validation, the model proficiently predicted optimal parameters conducive to the production of smooth, bead-free nanofibers. The model achieved a root mean square error (RMSE) of 7.77%, which is lower than previous models for predicting electrospun Kefiran nanofiber diameter.The results indicate that the ANN-based methodology substantially augments the efficiency and precision of electrospinning parameter optimization, thereby providing a significant resource for researchers and engineers engaged in the domain of nanomaterials. Future investigations could delve into the application of this model to various polymer systems and further refine the ANN architecture to accommodate more intricate electrospinning configurations.

NUMERICAL MODEL ANALYSIS OF SUBGRADE SETTLEMENT WITH FOAM MORTAR REINFORCEMENT BASED ON THICKNESS VARIATION

Ulfa Jusi, Pratikso, Harnedi Maizir — Mon, 16 Dec 2024 00:00:00 +0100

Soft soils have low bearing capacity characteristics and can cause high settlement. Sub grade which becomes the lowest layer in road construction is expected to have a strong bearing capacity so that it can carry the construction load on it. To overcome this problem, it is necessary to reinforce it. Problems will arise if the thickness of the soft soil in the subgrade varies. So, it needs to know and identify the scale of declining that occurs if the soft soil variation is reinforced on it. Foam mortar is an alternative reinforcement that is expected to improve the properties of the soft soil. The purpose of this research is to analyze the soft soil embankment model using foam mortar reinforcement against variations in soft soil height. The method of analysis was carried out by numerical method of Plaxis 2D version 2023. The geometric model in this study with foam mortar thickness of 30 cm was varied against subgrade layer height of 60 cm, 120 cm and 180 cm. The modeled load is a centralized load with variations of 0, 10, 20, 40, 60, 80, 100 and 120 kN. Numerical results obtained the highest settlement occurred at 180 cm soft soil layer of 0.01421 mm. The largest deformation occurred in the soft soil layer of 1,461 x 10-3 mm. In conclusion, the thicker the soft soil layer, the higher the settlement and the greater the deformation.

NUMERICAL MODELING OF EMBANKMENT ON THIN CLAY SOIL WITH GEOFOAM

Muthia Anggraini, Pratikso, Harnedi Maizir — Mon, 16 Dec 2024 00:00:00 +0100

Soft soils cause problems in road subgrades because they have low bearing capacity. Embankments on soft ground need to be identified and reviewed before construction starts. Various soil reinforcement techniques can be used to improve soft soil conditions. This research focuses on using geofoam material as an embankment on soft soil. The aim is to analyze the modeling of soft soil embankment with geofoam. The research method is a numerical method using the Plaxis 2D version 2023 application. There are two models in this study, namely the embankment model without geofoam, 100 cm thick subgrade, and the embankment model with 30 cm thick and 40 cm thick geofoam. The embankment geometry model is assumed to be symmetrical, hardening soil parameters are used to model soft soil for analyzing consolidation settlement, and elastic linear parameters to model geofoam. The type of FEM analysis in this research is plain strain. Numerical results at a maximum load of 100 kN showed a settlement of 0.1587 mm at 30 cm geofoam thickness and 0.1507 mm at 40 cm geofoam thickness. Deformation of 16 mm in 30 cm thick geofoam and 15.22 mm in 40 cm thick geofoam. Soil stress of 201 kN/m² in 30 cm thick geofoam and 192 kN/m² in 40 cm thick geofoamm. In conclusion, the model of embankment on soft soil with geofoam is that the thicker the geofoam used, the smaller the settlement and the stress on the soil that occurs.

THE STUDY OF ACCURACY OF AN OPERATOR’S PERCEPTION OF GEOMETRICAL OBJECT SIZES AND SHAPES IN THE VIRTUAL ENVIRONMENTS

Tue, 17 Dec 2024 00:17:43 +0100

This paper is devoted to the experimental comparison of accuracy of an operator’s perception of geometrical object sizes and shapes between the different conditions of information perception in the virtual environments and from the electronic displays. The experiments were conducted using a psychophysiological test for the accuracy of perceiving geometrical object sizes and shapes by an operator in the virtual environments and in the conditions of information perception from an electronic display. As a common metric of the accuracy of perceiving geometrical object sizes and shapes, an operator was offered to visually determine the object center of gravity. No significant differences in the measurement results of both the accuracy of perceiving geometrical object sizes and shapes and speed of this process were found based on the different methods of displaying the visual information to an operator.

CORRIGENDUM TO “DESIGN OF A COOLING SYSTEM FROM UNDERGROUND THERMAL ENERGY STORAGE (UTES, UNDERGROUND) THERMAL ENERGY STORAGE) BASED ON EXPERIMENTAL RESULTS”

Nada Stanojevic — Tue, 17 Dec 2024 00:28:38 +0100

In October 2024, co-author Marcelo Rodrigo Garcia Saquicela pointed out the need to supplement his affiliation. The supplementation was necessary as the work presented in published article was conducted through the involvement and engagement of two institutions.

Following a request by co-author Marcelo Rodrigo Garcia Saquicela, supported by all co-authors, the Editor-in-Chief has approved the following correction for the article published in 22(2024)2, 1203, 386-392, DOI: 10.5937/jaes0-46295:

José David Barros Enríquez¹*, Milton Iván Villafuerte López¹, Angel Moises Avemañay Morocho¹, Diego Javier Punina Guerrero², Marcelo Rodrigo Garcia Saquicela^{3, 4}

¹ Faculty of industrial and production sciences, Quevedo State Technical University (Uteq), Quevedo, Ecuador

² Faculty of mechanical engineering, Polytechnic Higher School of Chimborazo (Espoch), Riobamba, Ecuador

³ Faculty of engineering and applied sciences, University of the Americas (Udla) Quito, Ecuador

⁴ Faculty of Engineering Sciences, State Technical University of Quevedo, Los Rios, Ecuador

* jbarros@uteq.edu.ec