KUFA JOURNAL OF ENGINEERING

Increasing the strength of the matrix material rather than increasing stiffness is frequently the primary objective when designing composite materials. This is typically the case when the matrix is made of brittle, low-strength material. the resilience of this matrix substance Usually, it is determined by the initial flaws in the raw material. Depending on the microstructure of the composite material, these flaws or fissures may be large or minor. The orientations of the foil fibers, which can be customized to improve the performance of the laminate, have a significant impact on the properties of fiber reinforced polymer (FRP) laminates.

This study's goal is to look at how matrix cracking affects the mechanical characteristics of FRP chips. The presence and absence of exterior cracks are examined in unidirectional glass fiber reinforced polymer strips. Samples were manually cast using plastic molds constructed in accordance with ASTM standards. It were able to comprehend the impact of external cracking on composite materials through the mechanical tests that were conducted since it causes the material to weaken. Consequently, it is seen as a location where tensions are concentrated.

This work introduces an investigation of the surface roughness (Ra) during flat plate machining utilizing magnetic abrasive finishing process (MAF). In this study three parameters (Machining time, Mesh size, and Gap) were studied. The MAF tool is made from permanent magnet and the abrasive powder is consisting of 40% of SiC and 60% Fe powder with three Mesh size (100, 250, and 400 µm). The Taguchi L9 array was used in designing the experiments. The results show that the increasing machining time caused a decrease in Ra. The increase in mesh size and the gap will increase the surface roughness. The dominant factor that affect the surface roughness was the machining time due to enough time to machine the target surface.

In this research, we investigate how human-computer interaction (HCI) can be used to improve the user experience (UX) of interactive systems. Studies in cognitive psychology, information processing, and human factors are examined as they relate to the development of HCI. It highlights how HCI has shifted its focus from functionality to user-friendliness, teaching ability, efficiency, enjoyment, and emotion. To better understand the current state of HCI and UX research, practice, and theory, a systematic literature study is performed. Focusing on users' goals wants, and characteristics at every stage of the design process is central to user-centered design (UCD) ideas and approaches, which are discussed at length in this article. We investigate usability testing as a crucial technique for bettering HCI, focusing on its advantages in pinpointing usability problems, boosting system efficacy, and boosting user pleasure. Methods for creating tests, finding participants, collecting data, and analyzing results are discussed. The importance of prototype methods in HCI and user-centric design is also emphasized in the study. This article delves into the practice of creating prototypes to collect user feedback, iterate designs, and perfect interactive systems. Techniques covered include paper prototyping, interactive wireframes, and high-fidelity prototypes. We propose interaction design frameworks like the User-Centered Design Process (UCDP) and the Double Diamond model to help designers prioritize users when developing interactive systems. The study also delves into how technologies like augmented reality, virtual reality, natural language processing, machine learning, and gesture-based interfaces have revolutionized HCI in recent years. The paper defends user-centric design's place in HCI, pointing out how UX affects user happiness, participation, and output. Researchers and practitioners in HCI and software engineering can greatly benefit from this paper's findings.

Single Point Incremental Forming (SPIF) has emerged as a promising technique for shaping complex geometries in various materials. This study investigates the influence of process parameters, specifically step size and tool diameter, on the SPIF of titanium sheets. The experiment comprises three different step sizes (0.2, 0.4, and 0.6 mm) and three tool diameters (6, 10, and 14 mm), applied to titanium sheets. The research focuses on evaluating the impact of these parameters on three crucial aspects of SPIF: thickness reduction, fracture depth, and forming angle in the fracture zone. Through a series of experiments, the relationship between step size, tool diameter, and these performance indicators is thoroughly examined. Results indicate that smaller step sizes lead to higher thickness reductions and more precise forming angles in the fracture region and smaller tool diameters also increased fracture depths. Understanding the interplay between these parameters is vital for optimizing SPIF processes in titanium sheet forming applications, offering insights for enhanced production efficiency and quality in industries relying on advanced forming techniques. The CNC forming process took about 10 hours.

The experimental investigations of rotating heat exchangers are usually too costly and provide limited understanding for the phenomena of heat and fluid flow within them; hence, a less expensive and more comprehensive method is required to investigate what can affect their overall performance. In the current study, a porous media concept is presented as an alternative way to numerically analyse the fluid flow and heat transport through a rotary thermal regenerator. An aluminum core formed of multi-packed square passages is simulated as a porous medium of an orthotropic porosity in order to allow the counter-flowing streams to flow in a way similar to that inside the regenerator core. The geometric properties of the core were transformed into the conventional porous media parameters such as the permeability and inertial coefficient based on empirical equations; so, the core has been dealt with as a porous medium of known features. Fluid and solid phases are assumed to be in a local thermal non-equilibrium state with each other. A commercial CFD code "STAR CCM+" was used to solve the current problem numerically, where heat is allowed to be exchanged between the two phases and tracked by creating a heat exchanger interface in the core region. The results are presented by means of overall thermal effectiveness, pressure drop, and coefficient of performance COP. Using porous media approach has been found to be sufficient to simulate the current problem, where the currently computed data were found to deviate by up to 2.7% only from the corresponding analytical and experimental data. The data obtained reveal an obvious impact of the core geometrical parameters on both the heat restored and pressure loss; and hence, the overall efficiency of the regenerator system.

Thermoelectric generators are solid-state devices that convert heat into electricity using the Seebeck effect, when there is a temperature difference across a thermoelectric material. This research designed an experimentally tested a thermoelectric hot air generator using sixteen SP1848-27145 modules in two parallel strings. The system consists of a biomass combustion chamber, hot air exhauster, hot and cold side heat exchangers. Voltage, current and temperatures in the combustion chamber, hot air heat exhauster, hot side heat exchanger and cold side heat sink were measured. The hot air exhauster, hot side heat sink and cold side maximum temperatures are 178.3°C, 69.2°C and 44.5°C respectively yielding an open circuit voltage of 64 V and current of 1.99 A in the course of the experiment. The thermal performance of the designed hot air exhauster, hot side heat exchanger and cold side heat were simulated using ANSYS Fluent, for pictorial representation of their temperature contours.