Designs, Volume 7, Issue 6 (December 2023) – 25 articles

Polymers have gained a foothold in the international market and are actively utilized at a large scale in various industries. They are used as sliding layers in various types of friction units. However, there is a lack of research on their deformation behavior under different design conditions. This work is focused on studying the influence of the geometrical design of lubrication recesses in a polymer sliding layer operating under conditions of frictional contact interaction. The article investigated an element of bridge-bearing steel plate with recesses for lubrication. Two geometrical configurations of recesses are studied: the annular groove and spherical well in the engineering software package ANSYS Mechanical APDL. Polytetrafluoroethylene (PTFE) is considered an elastic-plastic sliding layer. A comparative analysis of two models with different geometrical configurations of cutouts for lubrication, with/without taking into account its volume in the recess, has been conducted. The article establishes that in the absence of lubrication in the recesses, large deformations of the polymer sliding layer occur. This effect negatively affects the structure as a whole. Changing the geometry of the recess for lubrication has the greatest effect on the intensity of plastic deformations. Its maximum level is lowered by almost ~60% when spherical notches are used for lubrication instead of grooves. The friction coefficient of the polymer has a great influence on the contact tangential stress. At the experimental coefficient of friction, it is lowered on average by ~85%. The friction coefficient of the lubricant has almost no effect on the deformation of the cell (<1%). Full article

Modular precast construction is a methodological approach to reduce environmental impacts and increase productivity when building with concrete. Constructions are segmented into similar precast concrete elements, prefabricated with integrated quality control, and assembled just-in-sequence on site. Due to the automatised prefabrication, inaccuracies are minimised and the use of high-performance materials is enabled. As a result, the construction process is accelerated, and the modules can be designed to be lightweight and resource-efficient. This contribution presents the fundamentals of modular constructions made from precast concrete components. Then, to elaborate the requirements of a contemporary modular precast construction, the historic developments are described. Further, concepts and technical processes–comprehensible to non-expert readers–are introduced to formalise the discussion about the current state-of-the-art methods. Three case studies treating ongoing research are introduced and related to the conceptual fundamentals. The research is evaluated with regard to current barriers and future directions. In conclusion, modular precast construction is able to reduce emissions and increase productivity in the sector if researchers and firms coordinate the development of suitable technologies that bring value to critical stakeholders. Full article

Accurate pavement design and evaluation requires the execution of response analysis. Pavement materials’ behavior does not necessarily conform to the assumptions of the multi-linear elastic theory usually adopted during pavement analysis. In particular, the unbound granular materials located in the base and sub-base layers behave in a nonlinear elastic manner, which can be captured through advanced constitutive modeling of their resilient modulus. The finite element method enables us to code constitutive models and quantify potential variations in pavement responses because of different mechanistic assumptions. In this study, variations in response are investigated for a typical structure of a flexible pavement considering the nonlinear anisotropic behavior of the unbound materials together with their initial stress–strain state. To demonstrate the impact of their behavior on the outcome of pavement analysis, variable asphalt concrete layer thicknesses and moduli are assumed, such that they cover a large spectrum of roadways. It was found that pavement responses can be calculated up to 3.5 times higher than those retrieved from the conventional linear analysis. This comparison means that the alterative mechanistic modeling of the unbound granular materials can be proved to be more conservative (i.e., leading to higher strains) in terms of pavement design and analysis. From a practical perspective, this study alerts pavement scientists and engineers engaged in pavement design to a more reliable performance prediction, which is needed to bridge the gap between advanced modeling and routine analysis. Full article

The development of electronic systems and wireless communication has led to a proportional increase in data traffic over time. One potential solution for alleviating data congestion is to augment the bandwidth capacity. This study presents a novel asymmetric circular slotted semi-circle-shaped monopole antenna design using a defective ground structure. The extended ultrawide bandwidth is achieved by implementing a design where the semi-circle radiator is etched in a specific asymmetric circular slot. This involves etching a circle with a radius of 1.25 mm at the center of the radiator, as well as a succession of circles with a radius of 0.75 mm along the edges of the radiator. In addition, the ground plane is situated at a lower elevation and features a U-shaped truncation that has been etched onto its surface. The expansion of the impedance bandwidth can be accomplished by making adjustments to the radiator and ground plane. The UWB antenna under consideration possesses a geometric configuration of 21.6 × 20.8 × 1.6 mm³ and the antenna is fabricated using an FR-4 glass epoxy substrate. The UWB antenna operates throughout the frequency range of 2.2–16.5 GHz, exhibiting a gain of at least 3.45 dBi across the entire impedance bandwidth and the maximum peak gain of 9.57 dBi achieved at the mid-resonance frequency of 10.5 GHz. The investigation of the antenna’s physical properties is conducted utilizing characteristic mode analysis. The investigation also includes an analysis of the time-domain characteristics, revealing that the group delay was found to be less than 1 ns across the operational frequency range. The predicted and measured findings demonstrate consistency and confirm that the suggested antenna is suitable for electronic systems and wireless applications. Full article

This study addresses the pressing energy constraints in nations like Bangladesh by proposing the implementation of photovoltaic (PV) microgrids. Given concerns about environmental degradation, limited fossil fuel reserves, and volatile product costs, renewable energy sources are gaining momentum globally. Our research focuses on a grid-connected solar PV system model at Char Jazira, Lalpur, Natore, Rajshahi, Bangladesh. Through PVsyst 7.1 simulation software, we assess the performance ratio (PR) and system losses, revealing an annual solar energy potential of 3375 MWh at standard test condition (STC) efficiency. After considering losses, the system generates 2815.2 MWh annually, with 2774 MWh exported to the grid. We analyze an average PR of 78.63% and calculate a levelized cost of energy (LCOE) of 2.82 BDT/kWh [1 USD = 110 BDT]. The financial assessment indicates a cost-effective LCOE for the grid-connected PV system, with an annual gross income of 27,744 kBDT from selling energy to the grid and operating costs of 64,060.60 BDT/year. Remarkably, this initiative can prevent 37,647.82 tCO₂ emissions over the project’s 25-year lifespan. Full article

As a result of the Internet of Things (IoT), smart city infrastructure has been able to advance, enhancing efficiency and enabling remote management. Despite this, this interconnectivity poses significant security and privacy concerns, as cyberthreats are rapidly adapting to exploit IoT vulnerabilities. In order to safeguard privacy and ensure secure IoT operations, robust security strategies are necessary. To detect anomalies effectively, intrusion detection systems (IDSs) must employ sophisticated algorithms capable of handling complex and voluminous datasets. A novel approach to IoT security is presented in this paper, which focuses on safeguarding smart vertical networks (SVNs) integral to sector-specific IoT implementations. It is proposed that a deep learning-based method employing a stacking deep ensemble model be used, selected for its superior performance in managing large datasets and its ability to learn intricate patterns indicative of cyberattacks. Experimental results indicate that the model is exceptionally accurate in identifying cyberthreats, exceeding other models, with a 99.8% detection rate for the ToN-IoT dataset and 99.6% for the InSDN dataset. The paper aims not only to introduce a robust algorithm for IoT security, but also to demonstrate its efficacy through comprehensive testing. We selected a deep learning ensemble model due to its proven track record in similar applications and its ability to maintain the integrity of IoT systems in smart cities. Full article

The use of coat-hanger dies is prevalent in the plastic film and sheet extrusion industry. The product quality and the power of the extrusion machine depend on the uniformities of the fluid velocity at the exit and the pressure drop. Die manufacturers face the challenge of producing coat-hanger dies that can extrude materials uniformly and with a minimal pressure drop. Previous studies have analyzed the die outlet’s flow homogeneity and pressure drop using various numerical simulations. However, the combination of the scheme programming language together with the Adjoint Method of Optimization has yet to be attempted. The adjoint optimization method has been demonstrated to be beneficial in addressing issues related to shape optimization problems and it may also be beneficial in optimizing the design of dies used in polymer melt extrusion. In this study, the proposed innovations involve incorporating both the Scheme programming language and Adjoint solver to examine and optimize the coat hanger’s flow homogeneity and pressure drop. Before optimization, the outlet velocity was almost 10 times higher at the die center than at the edges but after optimization, it became more uniform. The proposed optimized coat-hanger die geometry results in more uniform melt flow as demonstrated by the velocity contour plot and the outlet velocity graph in the die slit area, reducing the deviation value from 0.097 to 0.015. Additionally, the mass flux variance across the die outlet decreased by 71.6% from 0.015069 kg m⁻² s⁻¹ to 0.004281 kg m⁻² s⁻¹. Therefore, using this method reduces the amount of time wasted on trial and error or other optimization techniques that may be limited by design constraints. Full article

Aerial additive manufacturing (AAM) represents a paradigm shift in using unmanned aerial vehicles (UAVs, often called ‘drones’) in the construction industry, using self-powered and untethered UAVs to extrude structural cementitious material. This requires miniaturisation of the deposition system. Rheological properties and known hydration times are important material parameters. Calcium aluminate cement (CAC) systems can be advantageous over purely ordinary Portland cement (OPC) binders as they promote hydration and increase early strength. A quaternary OPC/pulverised fuel ash (PFA)/CAC/calcium sulphate (CS) system was combined with polyvinyl alcohol (PVA) fibres and pseudoplastic hydrocolloids to develop a novel AAM material for miniaturised deposition. CAC hydration is affected by environmental temperature. Intending material to be extruded in situ, mixes were tested at multiple temperatures. OPC/PFA/CAC/CS mixes with PVA fibres were successfully extruded with densities of ≈1700 kg/m${}^3$, yield stresses of 1.1–1.3 kPa and a compressive strength of 25 MPa. Pseudoplastic OPC/PFA/CAC/CS quaternary cementitious systems are demonstrated to be viable for AAM, provided mixes are modified with retarders as temperature increases. This study can significantly impact industry by demonstrating structural material which can be extruded using UAVs in challenging or elevated in situ construction, reducing safety risks. Full article

The most modern technique utilized to create intricate manufactured parts for a variety of applications is called additive manufacturing (AM). Fused deposition modeling (FDM) has been acknowledged as the greatest consideration in the development and industrial sectors. The main objective of this study was to investigate how printing factors affected the mechanical characteristics of printed samples. Samples were produced via an FDM 3D printer in compliance with an ASTM D638 using a variety of input settings, including orientation, layer thickness, speed, and infill pattern. Tensile tests and morphological analysis using a scanning electron microscope (SEM) were done on the printed samples. The results of this study demonstrate that factors including layer thickness, printing speed, and orientation significantly affect the tensile strength of the ABS-printed samples. The 45° orientations, 0.3 mm thickness, and normal speed had a significant impact on the tensile strength of the ABS-printed samples. On the other hand, samples with a 90° orientation, 0.4 mm thickness, and fast speed show better elongation performance than other samples, according to Young’s modulus results. The SEM results for microscopic analysis show that samples S2 (loose infill, 45° orientation, 0.3 mm thickness, and normal speed), S5 (solid infill, 45° orientation, 0.3 mm thickness, and normal speed), and S8 (hollow infill, 45° orientation, 0.3 mm thickness, and normal speed) had a highly packed structure and robust. Discovering the parameter settings that could lead to greater mechanical and physical characteristics would undoubtedly assist designers and manufacturers worldwide as the FDM 3D printer becomes more and more crucial in manufacturing engineering parts. Full article

This study aims to evaluate the precision of nine distinct hyperelastic models using experimental data sourced from the existing literature. These models rely on parameters obtained through curve-fitting functions. The complexity in finite element models of elastomers arises due to their nonlinear, incompressible behaviour. To achieve accurate representations, it is imperative to employ sophisticated hyperelastic models and appropriate element types and formulations. Prior published work has primarily focused on the comparison between the fitting models and the experimental data. Instead, in this study, the results obtained from finite element analysis are compared against the original data to assess the impact of element formulation, strain range, and mesh type on the ability to accurately predict the response of elastomers over a wide range of strain values. This comparison confirms that the element formulation and strain range can significantly influence result accuracy, yielding different responses in various strain ranges also because of the limitation with the curve fitting tools. Full article

The purpose of this paper is to summarize and share the field experiment results of KEPCO’s project consortium to create a TSO-DSO-DERA interaction scheme. The field experiment was conducted based on the prequalification algorithm proposed in previous research from the same consortium, and was designed to verify the validity of the algorithm under realistic grid conditions. In addition, during the course of the field experiment, it was found that points that were missed or not given much importance in the existing prequalification algorithm could affect the completeness of the overall system, and then practical improvements were made to improve this. The demonstration results confirm that the proposed algorithm is effective in real-world grid environments and can help DSOs to ensure the reliability of the distribution system while supporting DERA’s participation in the wholesale market using the proposed prequalification scheme. Full article

Metal-reinforced polymer composites are suitable materials for applications requiring special thermal, electrical or magnetic properties. Three-dimensional printing technologies enable these materials to be quickly shaped in any design directly and without the need for expensive moulds. However, processing data correlating specific information on how the metal particles influence the rheological behaviour of such composites is lacking, which has a direct effect on the processability of these composites through melt processing additive manufacturing. This study reports the compounding and characterisation of ABS composites filled with aluminium and copper particulates. Experimental results demonstrated that the tensile modulus increased with the incorporation of metal particles; however, there was also an intense embrittling effect. Mechanical testing and rheological analysis indicated poor affinity between the fillers and matrix, and the volume fraction proved to be a crucial factor for complex viscosity, storage modulus and thermal conductivity. However, a promising set of properties was achieved, paving the way for polymer–metal composites with optimised processability, microstructure and properties in melt processing additive manufacturing. Full article

The paper presents a methodology that integrates Quality-Function Deployment (QFD) and the Theory of Inventive Problem Solving (TRIZ) used for generating innovative solutions to design problems. It proposes a modified analytical House of Quality (HoQ) to reveal and prioritize contradictions between design parameters and between customer requirements. The proposed methodology extends the traditional HoQ and eliminates the need for the TRIZ’s Function Analysis (FA) procedure. Function Analysis involves identifying the functions of a product or process elements and trying to find contradictions between the system elements. The usability of the proposed method is illustrated through the redesign of an assembly workshop to overcome major problems addressed by the various stakeholders of the process. The new design of the assembly workshop helps reduce the number of work stages from 3 to 1, reduce the number of workers from 4 to 2, decrease rework, decrease the percentage of damaged products, enhance workplace ergonomics and improve the overall system efficiency. Full article

This study presents a systematic design of an optimized drive signal control system for 2.5 GHz Doherty power amplifiers (DPAs). The designed system enables the analysis of the independent control of the amplitude and phase for the signals between the main and peak amplifiers of the DPA. The independent control of the signal is achieved by incorporating a variable attenuator (VA) and a variable phase shifter (VPS) in each of the two parallel paths of the DPA. This integration allows for driving varying power levels with an arbitrary phase difference between the individual parallel PAs for reduced control complexity and power consumption. The specific VA (Qorvo QPC6614) and VPS (Qorvo QPC2108) components are used for the test system to provide an amplitude attenuation range from 0.5 dB to 31.5 dB and a phase range from $0^{\circ }$ to ${360}^{\circ }$ at the intended operating frequency of 2.5 GHz, offering the benefit of characterizing the behavior of PAs for an extensive range of drive signals to optimize the output performance, such as PAE or the ACLR. For experimental validation, the designed drive signal control system is integrated with GaN PAs (Qorvo QPD0005—DUT) with a $P_{1dB}$ of 37.7 dBm. Each PA is preceded by a drive amplifier with a gain of 17.8 dB to boost the power fed into the PA. In this manuscript, we analyzed and compared the PAE of the DPA and parallel-connected PA for diverse input signals generated using a designed optimized control system. Full article

This paper aims to demonstrate how design and digital media can have a relevant contribution to the improvement of Taekwondo athletes’ performance. This study focuses on answering the existing gap of a solution that allows quick and accurate access to data about the performance of martial arts athletes. This access to complex information, previously inaccessible or indecipherable to athletes and coaches, allowed, through digital design, the improvement of communication and a more personalized training feedback. The methodology developed was based on design thinking, in a work process that consisted of user identification, and the conception of a prototype in the user-centred design framework. The results obtained in the usability tests performed with Taekwondo athletes and coaches were demonstrative of the efficiency of the designed solution. These scores are also a stimulus for the potential replication and adaptation of the study in other martial arts. Full article

The primary benefit of metamaterials is that their physical and mechanical properties can be controlled by changing the structure geometry. Numerical analysis tools used in this work offer a few advantages over full-scale testing, consisting of an automated process, as well as lower material and time costs. The investigation is concerned with the behavior of unit cells of the tetrachiral mechanical metamaterial under uniaxial compression. The base material is studied within an elastic mathematical model. The influence of topological defects of the unit cell on the metamaterial properties is studied for the first time. Defects, and especially topological defects, play a decisive role in the mechanical behavior of materials and structures. The unit cell without defects reveals orthotropy of properties. Torsion of a cell with a chiral structure is induced by the rotation of all tetrachiral walls, and therefore it is sensitive to the introduction of defects. There are cases of increased torsion as well as of no compression–torsion coupling effect. In the latter case, the unit cell experiences only shear. The effective Young’s modulus is calculated to vary in the range from 23 to 57 MPa for unit cells of different topologies. With the successive introduction of defects in two walls, the studied characteristics increase, correlating with each other. A further increase in the number of defects affects the characteristics in different ways. The introduction of two more defects in the walls decreases torsion and increases Young’s modulus, after which both characteristics decrease. The introduction of topological defects in all walls of the unit cell leads to the orthotropic behavior of the cell with the opposite sign of torsion. Full article

Three-dimensional printing or additive manufacturing (AM) has enabled innovative advancements in tissue engineering through scaffold development. The use of scaffolds, developed by using AM technology for tissue repair (like cartilage and bone), could enable the growth of several cell types on the same implant. Scaffolds are 3D-printed using polymer-based composites. polyether ether ketone (PEEK)-based composites are ideal for scaffold 3D printing due to their excellent biocompatibility and mechanical properties resembling human bone. It is therefore considered to be the next-generation bioactive material for tissue engineering. Despite several reviews on the application of PEEK in biomedical fields, a detailed review of the recent progress made in the development of PEEK composites and the 3D printing of scaffolds has not been published. Therefore, this review focuses on the current status of technological developments in the 3D printing of bone scaffolds using PEEK-based composites. Furthermore, this review summarizes the challenges associated with the 3D printing of high-performance scaffolds based on PEEK composites. Full article

By progressively embracing the general principles of integrated, parametric, interdisciplinary design that considers the manufacturing elements of the imagined product, the modern aesthetic designer is called upon to broaden their knowledge and abilities. Especially when there is a need to produce complex shapes, when cost-effective, there are also numerous 3D printing technologies available today, to be used both in the conceptual phase (prototyping) and for actual production. The present paper aims to propose a discussion on the role of product engineering modelling in aesthetic design education. The progress of new 3D parametric modelling tools available to aesthetic designers is discussed, with a focus on the most cutting-edge features that have been released recently. The importance of parametric design education in general and the positive effects its application can have in the design process will also be discussed. Full article

The deterioration module (DM) is one of the four major modules necessary for any bridge management system (BMS). Environmental conditions, structural systems, bridge configuration, geographic location, and traffic data are some of the major factors that affect the development of deterioration modules. This emphasizes the need for the development of deterioration models that reflect the local conditions. In this article, some of the most important factors that could help in developing deterioration models in the Gulf Cooperation Council (GCC) were identified. The research was conducted in three phases; in the first phase, an extensive literature search was conducted to identify factors adopted in different deterioration models, and in phase two, the most relevant factors to the GCC environment were selected and these factors were further reduced based on input from local bridge experts. The result from the second phase is a list of factors identified by the experts. The identified list was utilized in phase three, which was focused on conducting a survey targeting bridge engineers to help identify the final selection and rank the factors according to their importance level. The results indicate that steel reinforcement protection, design load, chloride attack, type of defect, and age are the most important factors impacting bridge deterioration in the GCC. In addition, the time of rehabilitation; average daily truck traffic, ADTT; and average daily traffic, ADT, are the second most important factors. Factors with medium importance level are deck protection, services under the bridge, and inspection gap. The least important set of factors include temperature and wind load. Full article

The friction clutch design strongly depends upon the frictional heat generated between contact surfaces during slipping at the beginning of the engagement. Firstly, the frictional heat generated reduces the performance of the clutch system and then leads to premature failure for contacting surfaces in some cases. The experimental effort in this work included manufacturing friction facing from functionally graded material (FGM) (aluminum and silicon carbide) for the clutch system. For this purpose, a special test rig was developed to investigate the thermal behavior of FGM and compare it with other frictional materials. The Taguchi L9 orthogonal design was selected to analyze the effect of the three factors (rotational, speed, torque, and the type of the frictional material) with three levels on the surface temperature of the contacting surfaces. A three-dimensional finite element model was built to validate the experimental results where the difference between them did not exceed 5.2%. The experimental results showed that the temperatures grew with the disc radius. Furthermore, the surfaces of the pressure plates and the flywheel were affected by frictional heat flow, and this effect increased when increasing the sliding speed. The lowest temperatures occurred when using FGM, which was lower than the other materials by 10%. This study presented an integrated approach consisting of design, manufacturing, and testing to study the complex frictional materials’ effect on the clutch system’s tribological performance. Full article

With the increase in global temperatures, a significant threat of overheating has been reported due to more frequent and severe heatwaves in the UK housing stock. This research analyzes dwellings’ physical attributes through overheating assessments and their adaptation for modern flats in London in the current (2022) and anticipated (2050) weather. According to preliminary research, Southeast and London in England, mid-terraced, and flats (especially built post 2012), among other archetypes, were discovered to be the most susceptible to overheating in the UK. This study employed a case study of a 2015 modern flat located in a high-risk overheating zone in London to understand the building’s overheating exposure. A range of Dynamic Thermal Simulations (DTS) was conducted using EnergyPlus with reference to case studies in order to assess the performance of passive cooling mitigation strategies (PCMS) on peak summer days (15 July) as well as during the summer against CIBSE Guide A and ASHARE 55. Reduced window area and LoE triple glazing were identified as excellent mitigation prototypes, in which solar gains through exterior glazing were reduced by 85.5% due to triple glazing. Zone sensible cooling was reduced by 52%, which minimized CO₂ emissions. It was also identified that the final retrofit model passed CIBSE Guide A by achieving a temperature threshold of 20 °C to 25 °C during the summer months, whereas it failed to accomplish the ASHARE 55 criteria (20–24 °C). The outcome of this study justifies the necessity of tested PCMS and advises UK policymakers on how to foster resilient housing plans to overcome overheating issues. Full article

Due to climate change, Egypt has recently suffered from recurring electricity crises. Despite efforts made to increase electricity production in Egypt, recently, in the summer months, the energy demand has increased at unprecedented rates, especially in the housing sector. Therefore, the government and homeowners should work together to improve the energy performance of residential buildings. This paper aimed to develop a decision-making tool that helps homeowners choose optimal energy retrofit measures that suit their priorities. The study began with the data-collection and case study selection. Then, the thermal evaluation of the base case for dwellings in the case study was conducted through simulation runs using the DesignBuilder v7.1 software. Then, the optimal envelope energy retrofitting measures were determined, followed by a retrofitting-measure scenario simulation process. Then, the payback periods were calculated for all scenarios, and the tool database was developed using an Excel spreadsheet. Finally, the user interface for envelope energy retrofitting measures for gated communities (EERMGCs) tool was designed by Visual Basic for Applications. EERMGCs, the tool developed in this paper, is a simple, multi-objective and interactive tool that provides the optimal envelope retrofit measures according to user priorities, either a specific budget, the shortest payback period, the lowest possible costs, or the highest energy saving rate. The outcome of this research is developing a framework that can be considered a basis for developing decision-making tools for gated community housing in Egypt. Full article

Although free vibrations of thin-walled cylinders have been extensively addressed in the relevant literature, finding a good balance between accuracy and simplicity of the procedures used for natural frequency assessment is still an open issue. This paper proposes a novel approach with a high potential for practical application for rapid esteem of natural frequencies of thin-walled cylinders under different boundary conditions. Starting from Donnell–Mushtari’s shell theory, the differential problem is simplified by using the principle of virtual work and introducing the flexural waveforms of a beam as constrained as the cylinder. Hence, the formulation is reduced to the eigenvalue problem of an equivalent 3 × 3 dynamic matrix, which depends on the cylinder geometry, material, and boundary conditions. Several comparisons with experimental, numerical, and analytical approaches are presented to prove model reliability and practical interest. An excellent balance between fast usability and accuracy is achieved. The user-friendliness of the model makes it suitable to be implemented during the design stage without requiring any deep knowledge of the topic. Full article

Robust and well-designed rotor-bearing systems ensure safe operation and a high level of reliability under severe operating conditions. A deviation in the shaft axis with respect to the bearing longitudinal axis represents one of the most unavoidable problems in bearing systems. This deviation results from installation errors, manufacturing errors, shaft deformation under heavy loads, bearing wear, and many other causes. Each of these deviation sources has its negative consequences on the designed characteristics of the system. This work deals with the geometrical design of a journal bearing using three forms of profiles (linear $(n=1)$, quadratic $\left(n=2\right)$ and cubic $(n=3)$ profiles) in order to enhance bearing performance despite the presence of the inevitable shaft deviation. In addition, a wide range of bearing profile parameters are considered in the analysis to optimize the bearing profile based on the use of the Taguchi method. A general form of shaft deviation is considered to account for both horizontal and vertical deviations. A numerical solution is obtained using the finite difference method. The results show that all three suggested forms of bearing profiles elevate the film thickness significantly and also reduce the friction coefficient, but with different effects on the maximum pressure values. The Taguchi method illustrates that the optimal geometrical design parameters are the quadratic profile and the modification of one-fifth of the bearing width from both sides at a height of just less than half the radial clearance (0.4 C) at the bearing edges. These values give the best combination of the considered main bearing characteristics: the minimum film thickness, coefficient of friction, and maximum pressure. The results show that the minimum film thickness is increased by 184%, the maximum pressure is reduced by 15.1% and the friction coefficient is decreased by 6.4% due to the use of the suggested design. The outcome of this work represents an important enhancement step for the rotor bearing performance to work safely with high reliability under severe shaft deviation levels. This can be implied at the design stage of the bearing, which requires prior knowledge about the operating conditions in order to have better estimation for the levels of shaft deviation. Full article