Engineering Design Research Articles

X-ray astronomy from the lunar surface.

Motivated by efforts to return humanity to the Moon, three cases are reviewed for X-ray astronomy from the lunar surface: (i) facilitation of ambitious engineering designs including high-throughput telescopes, long focal length optics and X-ray interferometery; (ii) occultation studies and the gain they enable in astrometric precision; and(iii) multi-messenger time-domain coordinated observations. The potential benefits of, and challenges presented by, operating from the Moon are discussed. Some of these cases have relatively low mass budgets and could be conducted as early pathfinders, while others are more ambitious and will likely need to await improvements in technology or well-developed lunar bases. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades (part 2)'.

Impact assessment of critical success factors (CSFs) in public construction projects of Saudi Arabia

PurposeThere is a limited number of research work on critical success factors (CSFs) in public construction projects in Saudi Arabia. In response to this knowledge gap, the objective of this paper is to assess the impact of CSFs on the government construction projects in Saudi Arabia. The success factors are investigated from a broader consideration of failure criteria, from consideration of most effectiveness in successful project completion and also from consideration of the impact of implementing control processes for successful project completion.Design/methodology/approachThis study has analysed the impact of success factors on construction projects in Saudi Arabia using a descriptive methodology. An exhaustive literature survey is undertaken to identify the success and failure factors related to government construction projects in Saudi Arabia. The survey data are sorted out and analysed by cost, schedule, technical, context and finance dimensions of the projects based on project types, engineering complexity, size, modality, jurisdictional control and funding approach. To evaluate the influence of success factors implementation, qualitative data were collected in a survey via a web-based questionnaire that was sent to officials working and occupying a responsible position in national project guidelines organizations and in government construction organizations in Saudi Arabia. In all, 28 CSFs were identified, ranked and evaluated for their impact on project success. The four identified factors belong to process categories of construction projects, nine factors belong to management of construction projects and 15 success factors are identified for impact assessment of implementation in construction projects.FindingsThe study's findings have identified and ranked the top five CSFs that significantly influence project outcomes, including meeting time targets, adhering to financial budgets, delivering desired outcomes for all stakeholders, effectively managing risks and assembling the appropriate team while optimizing resource allocation. Additionally, the research indicates that hindrances to projects primarily stem from execution, economic, human and political factors. The study advocates for strict controls over incomplete engineering designs and advises against contractors independently handling design work to ensure project success. Additionally, addressing contractors' qualifications and financial matters is crucial for project success. By highlighting these CSFs and challenges, the research provides actionable insights to enhance project management practices in the construction industry.Research limitations/implicationsThis study is limited to the infrastructure projects constructed by governmental bodies with the participation of officials from government organizations. Further study, including private projects and officials working on private projects, may be needed to generalized the research outcome.Originality/valueNumerous studies have investigated CSFs in construction projects, but few have examined their relevance to Saudi Arabian government projects. This study aims to fill this gap by identifying key CSFs specific to Saudi Arabian public sector construction projects and assessing their impact on project success. It advocates for stringent controls in the Saudi Arabian construction sector, emphasizing the importance of preventing incomplete or altered engineering designs by contractors to increase the success rate of public sector projects. This research offers practical insights to stakeholders, advancing project management practices in Saudi Arabia's construction sector for improved outcomes and resource utilization.

Cohesion measurements between variables and methods using component-based software systems

AbstractThe practice of leveraging previously created software components to progress new software is identified as component-based software engineering (CBSE). Good software engineering design is the foundation of CBSE principles. The black box approach that underpins CBSE hides the execution of components in nature, and the components communicate with one another using strictly delineated interfaces. Component platforms are shared, which lowers the price of creation. To ascertain a system's complexity, various software metrics are employed. For superiority in software intricacy, coupling would be minimal, and cohesiveness must be high. It is predetermined that coupling should be low and cohesion should be increased for refinement in software complexity. We are identifying the combination of different software systems and improving the methods for doing so with our approach. Proposed: Cohm (cohesion of methods) and Cohv (cohesion of variables) are two cohesion metrics that have been proposed. The cohesiveness metrics in this study have been analytically and empirically evaluated, and a comparison has been made between them. Additionally, an effort was made to give the outcomes of an empirical estimation based on the case study. The T-test is used to determine the consequences of the metrics, and Python is used to validate the metrics. Python or R programming and the Matlab tool are used to determine the relationship between various variables and metrics. Findings: The consequence of the current investigation is very encouraging and might be used to estimate the involvedness of the parts. The proportional analysis of the proposed metrics and various cohesion metrics reveals that the suggested metrics are more cohesive than the present metrics, increasing the likelihood that they can be reused when creating new applications.

Paper or Tablet? The Impact of Digital Tools on Sketching During Engineering Design Concept Generation

Abstract Sketching is an important tool for engineers during concept generation. Sketch quantity during this early stage of design has been linked with eventual design outcomes and sketch quality has been linked with design perceptions. As such, both are important metrics to track. Prior work has also found gender differences in some of these sketch attributes. Given the increase in use of digital tablets for sketching, it is important to assess how tablet use affects early stage engineering design sketches. This is especially important as tablets can automatically smooth lines and help perfect sketch features, but these features may also take longer to use and may result in fewer sketches produced. This study investigates differences in sketch quality, quantity, and understandability (the effectiveness of the sketch as a communication tool) between sketching on a tablet and sketching with pen on paper during an engineering design concept generation exercise. Results indicate that there is no difference in sketch quantity or understandability between the two tools. However, sketch quality, smoothness, and proportion/accuracy are all higher for the pen and paper condition than for the tablet condition. Finally, no gender differences in performance for either sketch quantity or quality were found.

Nanostructured ZnO‐CQD Hybrid Heterostructure Nanocomposites: Synergistic Engineering for Sustainable Design, Functional Properties, and High‐Performance Applications

Hybrid nanocomposites integrating nanostructured zinc oxide (ZnO) and carbon quantum dots (CQDs) with designed heterostructures possess exceptional optical and electronic properties. These properties hold immense potential for advancements across diverse scientific and technological fields. This review article investigates the synthesis, properties, and applications of ZnO‐CQD heterostructure nanocomposites. Recent breakthroughs in fabrication methods are examined, including hydrothermal, microwave‐assisted, and eco‐friendly techniques. Key preparation methods such as sol‐gel, co‐precipitation, and electrochemical deposition are discussed, emphasizing their role in controlling heterostructure formation. This review analyses the impact of heterostructures on optical and electronic properties, such as fluorescence, photoluminescence, and photocatalytic activity. Synergistic interactions between ZnO and CQDs within heterostructures are highlighted, demonstrating how they lead to substantial performance improvements. Applications of ZnO‐CQD heterostructures span solar cells, LEDs, photodetectors, water purification, antimicrobial treatments, gas sensing, catalysis, biomedical imaging, drug delivery, environmental sensing, and energy storage. Insights are provided into refining synthesis methods, enhancing characterisation techniques, and broadening the application landscape. Challenges like stability are addressed, along with strategies for optimised performance and practical implementation.

Scraping Effect of Dam-Overtopping Debris Flow—A Case Study of Chutou Gully ‘8.20’ in Miansi Town, Wenchuan County

ABSTRACT After the May 12 earthquake in Wenchuan, numerous debris flow disasters occurred due to heavy rainfall. After the earthquake, disaster prevention and mitigation projects, such as the sand dam, played an essential role in safety. However, when the outflow of solid material exceeds the designed storage capacity of the sand dam, the debris flow overtopping the dam intensifies the scraping effect on the source material of the gully channel. This paper takes the ”8.20” debris flow in the Chutou gully as the research object. A transport mode of the debris flow after dam overtopping is studied through comprehensive field investigation, theoretical analysis, and indoor model tests. A quantitative evaluation model is established for the scraping depth and scraping volume of dam-overtopping debris flow. The study results showed that once the debris flow overtops a dam, the loose source carried by the channel is involved in the entire migration process, enlarging the fluid scale and intensifying the damage along the channel. The results agree with the measurements and observations, with maximum relative errors of 5.81% and 14.70%, respectively. This shows model validity. Furthermore, the test results show that the debris flow scarping phenomenon in the γ=[1.4 t/m3, 1.6 t/m3] interval is the most significant. Overall, this study will help improve future engineering decisions, design strategies, and finding the best design solutions to minimize the risk of dam-overtopping debris flow disasters.

Capillarity Constructed Open Siphon for Sustainable Drainage.

Siphon is an effective method to transfer liquid from a higher to a lower level, which has many applications in hygienic design, clinical apparatus, and hydraulic engineering. Traditional operation requires energy to overcome gravity and establish flow in a closed system. Achieving sustainable high flux siphon drainage without energy input remains a challenge due to viscous dissipation. Here, an unexpected open siphon behavior on the South American pitcher plant Heliamphora minor consisting of trichomes covered pitcher and a wedge-shaped sheath is examined. Exploiting the concept of Digital Twin, a new biomimetic research method by transforming the biological sample to a virtual 3D model is proposed and unveiled that maintained connection of wicking on sub-millimeter long trichomes due to asymmetric pressure distribution and ascending in wedge sheath under unbalanced pressure forms continuous surface flow. Exploring this mechanism, a biomimetic siphon device achieving continuous high flux exposed to ambient air is constructed. Besides, particles floating on the meniscus in the outside wedge move under a curvature gradient as water ascends, which implies a biological nutrient capture method and new dust collection manner in the drainage system. Applying the underlying principle enhances the siphon efficiency of floor drains and has the potential for other liquid transfer device design improvements.

PhysOM: Physarum polycephalum Oriented Microstructures

AbstractBiological shapes possess fascinating properties and behaviours that are the result of emergent mechanisms: they can evolve over time, dynamically adapt to changes in their environment, while also exhibiting interesting mechanical properties and aesthetic appeal. In this work, we bring and extend an existing biological‐inspired model of the Physarum polycephalum, aka the blob, to the field of computer graphics, in order to design porous organic‐like microstructures that resemble natural foam‐like cells or filament‐like patterns with variable local properties. In contrast to approaches based on static global optimization that provides only limited expressivity over the result, our method allows precise control over the local orientation of 3D patterns, relative cell extension and precise infill of shapes with well defined boundaries. To this end, we extend the classical agent‐based model for Physarum to fill an arbitrary domain with local anisotropic behaviour. We further provide a detailed analysis of the model parameters, contributing to the understanding of the system behaviour. The method is fast, parallelizable and scalable to large volumes and compatible with user interaction, allowing a designer to guide the structure, erase parts and observe its evolution in real‐time. Overall, our method provides a versatile and efficient means of generating intricate organic microstructures that have potential applications in fields such as additive manufacturing, design or biological representation and engineering.

Red-billed blue magpie optimizer: a novel metaheuristic algorithm for 2D/3D UAV path planning and engineering design problems

Numerical optimization, Unmanned Aerial Vehicle (UAV) path planning, and engineering design problems are fundamental to the development of artificial intelligence. Traditional methods show limitations in dealing with these complex nonlinear models. To address these challenges, the swarm intelligence algorithm is introduced as a metaheuristic method and effectively implemented. However, existing technology exhibits drawbacks such as slow convergence speed, low precision, and poor robustness. In this paper, we propose a novel metaheuristic approach called the Red-billed Blue Magpie Optimizer (RBMO), inspired by the cooperative and efficient predation behaviors of red-billed blue magpies. The mathematical model of RBMO was established by simulating the searching, chasing, attacking prey, and food storage behaviors of the red-billed blue magpie. To demonstrate RBMO’s performance, we first conduct qualitative analyses through convergence behavior experiments. Next, RBMO’s numerical optimization capabilities are substantiated using CEC2014 (Dim = 10, 30, 50, and 100) and CEC2017 (Dim = 10, 30, 50, and 100) suites, consistently achieving the best Friedman mean rank. In UAV path planning applications (two-dimensional and three − dimensional), RBMO obtains preferable solutions, demonstrating its effectiveness in solving NP-hard problems. Additionally, in five engineering design problems, RBMO consistently yields the minimum cost, showcasing its advantage in practical problem-solving. We compare our experimental results with three categories of widely recognized algorithms: (1) advanced variants, (2) recently proposed algorithms, and (3) high-performance optimizers, including CEC winners.

Expert Elicitation for the Resilient Design and Optimisation of Ultra-long Ore Passes for Deep Mass Mining

AbstractExtension of ore pass length has become increasingly critical for optimising energy-efficient underground mining operations. Long and ultra-long ore passes, spanning from 300 to 700 m, can significantly improve the functionality and viability of underground mass mining operations though suboptimal performance has an extremely adverse impact on production. The public domain lacks substantial information regarding the primary engineering, geological, and geotechnical risks and challenges associated with the design, implementation, operation, and maintenance of such long ore passes. Therefore, the aggregation of past experiences and the insights of experts assume paramount significance. An innovative methodology is introduced to address this evident data deficiency and to establish comprehensive guidelines for the resilient design of such lengthy ore passes — combining gap analysis with expert elicitation techniques. This equips design engineers with the necessary tools to formulate and adapt strategies for assessing the numerous challenges and uncertainties that invariably accompany their projects. Expert elicitation techniques are summarised, and a gap analysis is conducted with subject matter experts, from various countries, collating their extensive ore pass design experience, to create a comprehensive list of effective parameters and key risks that must be considered. Quantitative analysis of the survey results enabled the identification and ranking of the numerous factors affecting the design, operation, and maintenance of long and ultra-long ore passes and highlights the complex technical challenges (substantial damage from rock particle impact, increased dynamic mining stresses leading to failure, air-blasts and back blasts, dust, preferential flow, turbulent and dynamic material flow) that are uncommon in shorter ore passes. Additionally, increasing length heightens the probability of intersecting weak rock or discontinuities, leading to a higher risk of structural failure and instabilities. Faulting, folding, and large-scale structures are also critical geological factors to be considered in the design of such structures. The key geotechnical factor is also the rock type surrounding the pass. Experts highlighted the lack of clear guidelines for decision-making, resilient design, and construction so this work suggests future investigations to determine the complex interaction between the effective parameters, using approaches like the rock engineering system, discovery of cascading hazards, and optimal controls.

Motivation and the role of empathy in engineering work

ABSTRACT Societal perceptions of engineering as a discipline now depict engineering as a profession that enables social, economic, and environmental problems to be addressed on a global scale. This expanded view of engineering has had myriad impacts on priorities for engineering education and practice. One such impact has been to foreground discussions about the role that empathy may play in engineering practice. This manuscript discusses the evolution of the concept of empathy in the engineering field, and the relevance of empathy to various generic engineering attributes, including leadership, problem-solving, and design thinking. The manuscript then discusses the idea that motivation plays a central role in improving and increasing empathy in engineering work.

Developing Creative Thinking in STEM Education through Design- Based Learning

Creativity is one of the fundamental skills of the 21st century and has become a crucial task in education. This article provides a definition of creative thinking manifested in generating novel, unique, and valuable ideas and solutions to address posed problems. Characteristics of creativity such as fluency, originality, flexibility, and elaboration serve as indicators to evaluate the level of creativity in products of the engineering design process. Recognizing the importance of creativity in a dynamic world, creative education has been integrated into the mainstream education curriculum through the implementation of STEM teaching. Following this, the concept of design-based learning has been introduced as a STEM teaching approach based on integrating the engineering design process into classrooms, allowing learners to apply scientific and technological knowledge and skills to complex real-life problems. Finally, research in STEM education through the engineering design process to enhance learners' creative thinking has been synthesized. The aim is to provide ideas and guidance for teachers in organizing STEM teaching, aligning with the goal of fostering creativity for citizens in the digital age.

Multifunctional-Team Approach Achieves Extended-Reach Record Offshore Abu Dhabi

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 216326, “Longest Extended-Reach-Drilling Well Worldwide Drilled in Middle East, Offshore Abu Dhabi, UAE,” by Marah Mohamad Alabed, Naser Salah Alsuwaidi, and Jamie Scott Duguid, SPE, ADNOC, et al. The paper has not been peer reviewed. _ The complete paper describes the engineering design and operational practices that supported the setting of a new extended-reach world record in a mature carbonate field offshore Abu Dhabi. This accomplishment reduces the carbon footprint of the development, allows acquisition of reservoir data earlier in the development plan, and accelerates production while reducing costs. This extended-reach development program is a strong example of what can be accomplished when a multifunctional team cultivates a strategic plan to expand technical and operational capabilities in a drilling campaign. Reservoir and Development-Plan Background The 1-md oil reservoir is a carbonate dominated by packstone and grainstone rock types in terms of storage capacity. Average porosity is 18%, and thickness is 130 ft. Permeability reduces in an southeast/northwest direction, dropping below 1 md. Calcite cementation development has occurred in the westernmost areas of the reservoir because of late oil in these low structural areas. Initially, the target reservoir was drilled at 2-km well spacing with a five-spot waterflooding scheme from wellhead platform towers. Later, development was optimized by a line waterflooding scheme at 250-m well spacing by development from an environmental island. The target reservoir area was partitioned into four development areas (West A, West B, West C, and West D). The partition is based on drilling reachability from environmental islands and underlying geology. The current optimized development began in the West A reservoir area through an artificially constructed island. The remaining reservoir areas required investment of two new islands. High risk is associated with these investment decisions because these reservoir areas degrade in terms of reservoir rock properties. Additionally, an increasing trend of water saturation exists with progress in the northwest direction within the transition zone. The development plan in the West A area is based on drilling segments called AB and BC, first with over-20,000-ft laterals to achieve production buildup by target date. To test the West B area, Segment BC was extended, thus covering both West A and B areas. This option reduced drilling complexity and maximized the reservoir-production rate. Additionally, by adopting the island drilling option instead of appraising a limited area of West B, an extensive area of approximately 10 km could be appraised. To implement this option, a stepout drilling plan was executed by drilling eight extended-reach maximum-reservoir-contact wells in increments to meet the goal of appraising the West B reservoir area. These first wells were extended in increments of 1,000–2,000 ft to test the capability to drill and run completion to target a measured depth (MD) of 45,000 ft. Upon applying learnings from these pilot wells, a stepout to extending wells to 50,000 ft MD and greater was studied. Fig. 1 shows the map of the subject drilled well with an extended MD of 50,000 ft with an underlying oil-saturation map. This optimized field-development strategy has allowed for effective West B reservoir appraisal.

Promoting knowledge recommendation in innovative engineering design: a BERT-GAT-based patent representation learning approach

Since innovation in complex product design hinges on thorough engineering knowledge application, high-quality patent recommendations foster innovation in engineering design. However, many patent knowledge recommendation studies perform patent analysis without comprehensive exploration and proper organisation of knowledge, causing a superficial understanding of patents and returning arbitrary results. To mitigate this issue, a deep learning-based approach for patent representation learning and knowledge recommendation is proposed. First, a four-dimensional patent knowledge model is defined to formalise the patent attributes that critically affect the engineering design outcomes, namely patents’ domain(D), function(F), technology(T) and citation(C). Second, to exploit patent knowledge from their content and citation relationships, a representation learning approach integrating Bidirectional Encoder Representations from Transformers(BERT) and Graph Attention Network(GAT) is introduced. Thereafter a patent knowledge space is established in which each patent is characterised by the function, technology, and citation embeddings. Third, a knowledge requirement space is also constructed by vectorising a designer’s search query via BERT model and linking it to a requirement-representing patent based on similarity. Finally, a recommender prototype is developed and showcased by the knowledge recommendation in sealing structure design tasks. Comparative experiments and application cases validate the effectiveness of our method in patent representation learning and knowledge recommendation.

A novel constitutive law of confined grouted rock bolt under pull-out load based on a fully nonlinear bond-slip model

Rock bolts are widely applied in deep underground excavations for rock reinforcement. Here, a constitutive model that quantifies the pull-out load-displacement relationship of the grouted rock bolt has been developed though theoretically analyzing the load transfer behaviour along the bolt-grout interface. An improved nonlinear continuously yielding criteria was employed as a bond-slip model where the role of confining pressure playing in slip was accounted. The performance of the proposed constitutive model was demonstrated by comparing with three sets of laboratory pull-out tests on the fully grouted rock bolts under different confining pressure levels (including a short-encapsulated pull-out test designed in our laboratory). The input parameters in the model were determinable within the laboratory environment. The analytical simulation results of pull-out load-displacement performance, the axial stress in the rock bolt and shear stress along the bolt-grout interface agreed well with the laboratory data. We also found that the confining pressure significantly affects the critical embedment length and the higher the confining pressure, the shorter the critical embedment length. The findings enrich the understanding on the mechanical properties of grouted rock bolts and hence aid the rock engineers in rock reinforcement design in underground excavations.

Oriented Interpenetrating Capillary Network with Surface Engineering by Porous ZnO from Wood for Membrane Emulsification

Membrane emulsification technology has garnered increasing interest in emulsion preparation due to controllable droplet size, narrower droplet size distribution, low energy consumption, simple process design and excellent reproducibility. Nevertheless, the pore structure and surface engineering in membrane materials design play a crucial role in achieving high-quality emulsions with high throughput simultaneously. In this work, an oriented interpenetrating capillary network composed of highly aligned and interconnected wood cell lumens has been utilized to fabricate an emulsion membrane. A novel honeycomb porous ZnO layer obtained by a seed prefabrication–hydrothermal growth method was designed to reconstruct wood channel surfaces for enhanced microfluid mixing. The results show that through the unique capillary mesh microstructure of wood, the emulsion droplets were smaller in size, had narrower pore-size distribution, and were easy to obtain under high throughput conditions. Meanwhile, a well-designed ZnO layer could further improve the emulsion quality of a wood membrane, while the emulsifying throughput is still maintained at a higher level. This demonstrates that the convection process of the microfluid in these wood capillary channels was intensified markedly. This study not only develops advanced membrane materials in emulsion preparation, but also introduces a brand-new field for functional applications of wood.

Study on overburden failure characteristics and displacement rule under the influence of deep faults

Deep faults significantly impact the structural stabilities and deformation behaviors of their overburden rocks, which are key factors in underground engineering and geological hazard research. Considering the problem of deep-fault-overburdened breaking during mining of super-thick coal seams and taking the Yaoqiao Coal Mine as the research object, the mining fracture evolution characteristics and overburden displacement law of the non-structured and fault-bearing overburden corresponding to fully mechanized caving mining are compared and analyzed using numerical simulations and physical similarity simulations. The results of this study show the following: 1) The fracture height of the overlying rock presents a specific change law with advancement of the working face; the initial rapid increase to a maximum height of 74 m is achieved when the working face advances to 90 m; with the development of the plastic zone indicating past yield, the fracture height decreases to 54 m and becomes stable, and the final caving angle of the fracture stabilizes at 70°. 2) In coal mining under normal fault conditions, when the working face advances from the upper to lower walls, the roof forms a masonry beam structure that slows down fault activation and crack development. When moving away from the fault, the overburden movements and water-conducting cracks are fewer, and the crack height is lower than that without faults. When approaching the fault, the influence of the faults in the fracture zone increases, and the height of fracture development reaches the maximum value after crossing the fault, highlighting the significant influence of the fault on fracture development. 3) Through a similarity simulation test, it is shown that the overburden caving zone is further compacted by the overburden rock and that the roof collapses in a large range, resulting in rapid upward development of the overburden rock cracks and separation of the central overburden rock cracks that are gradually compacted and closed. These findings are expected to have important theoretical and practical significance for deep underground engineering design, geological disaster prevention, and fault activity monitoring.

Enhancing the Outcome of Mechanical Engineering Design Course with the SCAMPER Methodology Framework

Methodology frameworks in engineering education are structured approaches or models used to design, implement, and evaluate educational practices in engineering disciplines. These frameworks provide a systematic way to organize and optimize the teaching and learning process, ensuring that engineering students receive a comprehensive and effective education. SCAMPER is a creative thinking technique used to generate new ideas and approaches for problem-solving or project development. Each letter in SCAMPER stands for a different prompt to enhance the process targeted. These prompts stand for the substitute, combine, adapt, modify, put to another use, eliminate, and reverse. Evolving SCAMPER as a methodology framework for Mechanical Engineering education involves adapting its principles and prompts to cater specifically to the needs and challenges of engineering students. This study presents the use of SCAMPER methodology as an educational framework for mechanical engineering and application to the Mechanical Engineering Design course given for senior year students with proposed examples based on experiences collected from previous classes thought.

A simplex approach for binary linear programming

This article is a research, design, and development effort, on an algorithm for Binary Linear Programming (BLP). The idea of the algorithm is based on the concepts borrowed from the Simplex method of Linear Programming (LP). The Simplex method has both column selection and row selection logics for generating a pivot. In this article we select both logics of LP to use as only the column selection logic for the BLP. The article provides the complete implementable C-language source code of this version of the BLP algorithm to show all the details of the logics. In addition, it provides a simple software requirement for embedded engineering products based on the laws of nature. It helps to design, modify, and maintain a simpler code for the algorithms. Therefore, the article uses a multidisciplinary approach. It integrates optimization theory, matrix algebra, computer programming, software engineering design requirements, social science, laws of nature, etc. This BLP algorithm will shed some light on the P-NP problem and its solution.

Experimental study on seismic performance of squat precast concrete sandwich shear walls under low axial load ratio

To improve the thermal performance and seismic resistance of structures, precast concrete sandwich shear wall (PCSSW) emerges as a promising option due to its low thermal conductivity and favorable structural performance. This study aims to examine the effectiveness of a new type of vertical connection between the PCSSW and foundation under reversed cyclic loading. The proposed vertical connection is achieved by embedding steel bars in the precast wall and foundation, respectively, followed by casting fresh concrete in place. Considering pre-embedded steel bar arrangements (single-row or double-row) and cast-in-place (CIP) concrete strength as variables, three precast specimens were designed. Seismic performance was investigated through low reversed cyclic loading tests, with a comparison made against two CIP control specimens. The results showed that the behavior of all the tested walls was governed by shear, with the ultimate bearing capacity of the PCSSW determined by the horizontal shear capacity at the weak position. Under low axial compression ratios, the specimens with double-row steel bar arrangement had higher load-carrying capacity and ductility than single-row steel bar arrangement and could be equivalent to the CIP shear walls. Results from this study were compared with the predicted values from different codes to provide some reference value for the engineering design of the proposed structure.