Early Design Stage Research Articles

Unlocking policy success: is codesign the key to achieving effective policy outcomes?

Codesign is increasingly promoted as best-practice and a solution to many policy ills, yet there is little empirical evidence suggesting that it is actually more effective for designing and implementing policy. This article investigates whether codesigned policies and programs are in fact more successful in achieving positive policy outcomes by applying the policy success framework to the codesign process behind the Australian Capital Territory’s Family Safety Hub. Using this framework, we conclude that codesign can have a significant positive impact on the process when it is done well, but its effect on longer-term program and political success depends heavily on other factors. The use of codesign as a stand-alone policy tool is limited, but further research is needed to understand how the value it generates in the early design stages can be translated into better implementation and positive program outcomes.

Static strength assessment of short glass fibre-reinforced polyphenilenesulphide in presence of notches according to different approaches

In this paper the static behaviour of polyphenylenesulfide reinforced by 40% wt. short glass fibre net-shaped plain and notched specimens was investigated. The specimen geometries were obtained by injection moulding and the experimental results were compared with data obtained from machined specimens with the same material and geometries. All data were reanalysed according to several models available in the literature for orthotropic materials, to find a rapid and efficient assessment tool for predicting the strength of short glass fibre reinforced materials in the early design stages. To this end, approaches based on orthotropic linear elastic stress analysis were considered, namely the linear elastic peak stress criterion, the nominal net-stress criterion, the point stress criterion, the average stress criterion, the strain energy density criterion, the generalized stress intensity factor-based approach, the inherent flaw model, the damaged zone criterion and the Hitchen criterion. Among the models, the average stress criterion and the generalized stress intensity factor-based approach provided the most accurate predictions of the static strength, ranging from −10% to +9% and from −19% to +2%, respectively, compared to the experimental data.

Geometry Optimization of Industry Buildings for Energy-Driven Design Development in Bangladesh

Even though the manufacturing industry consumes roughly 54% of total available energy globally, little consideration has been devoted to optimizing energy in the early stages of industry design, particularly in densely populated cities. With the increased demand for green buildings, energy performance has a greater influence on design results. As a result, this paper provides an envelope optimization technique that can assist architects and computational designers in analyzing the environmental performance of various alternatives and developing optimal design solutions, especially for Bangladesh and the building of these regions. First, an existing industrial site in Dhaka, Bangladesh's capital was chosen as a case study, and a hypothetical industry building, as well as its surroundings, were parametrically developed. Then, for the optimization method, the design factors linked to the building envelopes were chosen. Finally, a Multi-objective Optimization (MOO) procedure was utilized for defining performance measures including daylighting, energy and comfort measures, UDI, EUI, and PPD. According to the MOO results, the UDI may be enhanced by 25.286% as compared to the least favorable scenario. Consequently, the EUI may decreased by 38.718 kWh/m2 while the PPD can be increased by 41.78%. The geometric configuration of East, West, North, and South played a significant role when designing the industrial building. According to the analysis, the geometric configuration of a South WWR of 50%, a West WWR of 30%, an East WWR of 70%, and a sill height of 0.75m is the most feasible option. A statistical analysis of design factors and performance measures demonstrated that the window-to-wall ratio, particularly on south walls, has the greatest impact on industrial building design in densely populated areas. The proposed approach is expected to be used by architects and municipal planners to develop design metrics based on simulation results.

An evidence theory-based uncertainty quantification method of building thermal parameters for accurate reliability assessment of building air-conditioning design loads

Probabilistic methods are frequently employed in the reliability assessment of building air-conditioning design loads to quantify the uncertainty associated with building thermal parameters. However, its implementation requires some assumptions because of inadequate data in the early stages of design. These assumptions cause the uncertainty quantification results of the building thermal parameters to differ from reality, which may lead to a significant overestimation or underestimate of reliability. Therefore, an evidence theory-based method was proposed to quantify the uncertainty of the building thermal parameters. In this method, evidence theory was employed instead of probability theory because the former could make full use of small sample information to achieve objective uncertainty quantification. Taking an office building in Tianjin, China, as an example, the new method was tested, and its effectiveness was verified. The results showed that the uncertainty quantification results of the building thermal parameters based on the new method included those of the benchmark method. Under small sample conditions, the reliability assessment results based on the new method were closer to those of the benchmark compared with the traditional method.

Evaluation of Sonic Boom Shock Wave Generation with CFD Green Methods

Over the past two decades, there has been a renewed interest in the development of a new generation of supersonic aircraft for civil purposes that could potentially succeed Concorde. However, the noise annoyance is still considered one of the hampering factors to meet public consensus. This paper aims at revealing the potential of numerical simulations to predict sonic boom signature in Near Field at early design stages. In particular, the paper further demonstrates the applicability of the numerical approach proposed by NASA and other partners during the Sonic Boom Prediction Workshops held between 2014 and 2021, to compute the pressure signature of aircraft in the zone close to it. The results highlight the suitability of the approach (1) to capture the impact of aircraft flight condition variations on the sonic boom signature, (2) to enable the characterization of novel aircraft layout, including Mach 5 waverider configuration, (3) to provide near-field shock wave noise predictions that can be used to evaluate shock propagation, on-ground signature analyses, and annoyance assessment.

An interactive method for generating and evaluating urban design alternatives in early design stages

The field of generative design strives to enable the automated generation of multiple suitable urban design alternatives. However, quantitative analysis is typically conducted in the later design stages, when options are limited, and modifications are costly. Generative methods enable the creating of designs that bridge traditional methods, through systematic examination of numerous options during the early design stages. Yet their utilization in architectural practices is limited, partly due to antagonism that stems from the perceived lack of involvement of urban designers in such methods (which often behave like black boxes). The objective of this study was to develop a generative design process that combines rule-based automated algorithmic processes with the active involvement of urban designers, thereby offering a wide range of design alternatives during the planning phase. Additionally, the study aims at ensuring the key involvement of urban designers throughout the design process. The methodology employed in this study is comprised of both quantitative and subjective evaluations that the urban designers can conduct themselves. This result is an interactive process that utilizes generative tools and computerized analytical measures for creating, evaluating, and screening multiple urban design options at the urban neighborhood level, with an emphasis on residents’ well-being, and based on the designers’ preferred parameters. This parametric workflow could assist designers in the early decision-making process and may be integrated into current urban design processes.

A Biomimetic Sketch-Based Form Finding Tool

Sketches play a fundamental role in the design disciplines, serving as crucial representations for ideation, problem-solving, and communication. In the realm of architecture, sketches encapsulate the evolution of ideas from conceptualization to construction. Hand-drawn sketches, characterized by their open-ended, ambiguous nature and rapid production, stand out as indispensable tools in bridging the gap between abstract concepts and tangible designs, guiding the progression from early design stages to final product realization. However, despite their significant potential and pivotal role in the design process, hand sketches have often been overlooked and swiftly abandoned in the ongoing discourse surrounding traditional versus digital design methodologies, particularly with the widespread integration of computer technologies. This study endeavors to unlock the wealth of information embedded within hand sketches, spanning from initial design concepts to intricate manufacturing details, through the utilization of a hybrid digital form-finding tool. By employing swarm algorithms in the quest for form, it is anticipated that the boundaries of conceptual ideas delineated by hand sketches will be expanded. This is facilitated by an algorithm developed in Processing using the Java coding language, complemented by an intuitive interface. The research journey commences with a comprehensive literature review encompassing biomimetics, sketching techniques, and tools for transitioning hand sketches into digital realms. Subsequently, a thorough elucidation of the algorithm, crafted within the Processing environment, is provided.The efficacy of the tool is assessed through experimentation involving adjustments of various parameters on identical sketches, as well as application to seven architectural sketches representing built designs, with subsequent interpretation of the outcomes. It is posited that the adaptability of the algorithm's core logic, coupled with the development-friendly environment of Processing, holds immense potential for empowering designers to steer sketches in desired directions through tailored enhancements.

A novel framework for quantitative resilience assessment in complex engineering systems during early and late design stages

Recently, resilience assessment has evolved and grown in prominence, yet most studies are carried out on operational stage when sufficient knowledge on the processes is available, overlooking the design stage, a time frame that is more suitable for making a resilient system. To this end, this work aims at developing a novel quantitative resilience assessment framework for engineering systems with two different approaches that practically analyse resilience at the early and late design stages when detailed information on the system’s safety and resilience capabilities may be deficient. In the early design stage, system resilience attributes are identified, and expert judgment is used to assess their quality. In the late design stage, attributes are derived from revealed information such as detailed emergency response and safety barrier data. In both stages, dynamic Bayesian Network (DBN) is used to quantify resilience based on the acquired information. Since the green hydrogen technology is relatively novice, the application of the proposed framework is demonstrated in a resilience assessment of a green hydrogen plant undergoing hydrogen release scenarios. The proposed framework can be used as an effective tool for early design improvements as well as enhancing process safety in the late design stage of hydrogen plants or any other complex engineering system.

Coupling process controlling data and numerical simulation in mechanised tunnelling

AbstractNowadays, both process data management and numerical analysis are necessary for decision‐making in a tunnel project from its early design stage to the construction phase. Traditional generation of simulation models largely depends on tunnel design and reports, which are error prone due to the involvement of manual intervention. This article presents the application of a digital workflow to efficiently transfer automatically acquired data from tunnel projects to computational simulations. The application workflow is developed and executed through a web‐based environment. Project data from the Victory Boogie Woogie tunnel is retrieved from the process controlling software PROCON via web services to generate numerical simulations for settlement predictions at different tunnel sections. The simulated results are validated using real measured settlements in the project to prove the quality of the simulation model. Different scenarios of applying operational steering parameters are then investigated, utilising the simulation model, which can be used to support the on‐site engineers as an assistance system to drive the tunnel boring machines. The work has been carried out within the framework of the transfer project T2 of the Collaborative Research Center “Interaction Modeling in Mechanized Tunneling” (SFB 837), which aims to implement and test a digital twin for process control under practical conditions in the tunnelling industry.

Analysis of AP1000 Small-Break Loss-of-Coolant Accident Using Reactor Transient Simulator

The Westinghouse Electric Company’s Advanced Passive Reactor (AP1000) is characterized by the incorporation of passive safety systems (PSSs) designed to ensure core cooling during transient events. The assessment of PSSs requires evaluation of their performance through a combination of experiments and simulations employing various thermal-hydraulic codes. In addition, detailed evaluation of PSSs for a specific reactor system transient analysis such as loss-of-coolant-accident analysis supports understanding representative integral effects test facility development and the further evolution model development and assessment process. Developing a reactor system code is a complex and time-consuming process that requires significant engineering expertise and effort. It can take several months to even years to complete in the early stages of reactor system design and analysis. However, this process can be expedited through the use of transient simulator models for similar reactor systems, which can be used for lesson learning and training purposes. This study uses the Personal Computer Transient Analyzer (PCTRAN) code. The main advantage of PCTRAN is its ease of use and ability to run faster than real time. This study presents the results obtained for a small-break loss-of-coolant accident (SBLOCA) for two breaks using the full version (licensed) of PCTRAN. The purpose of this investigation is to evaluate the overall system behavior during the postulated SBLOCA event as well as assess the capability of the PCTRAN code to reproduce the system response during transient events. The obtained results were compared with the Westinghouse NOTRUMP system code. The PCTRAN code proved to be reliable in predicting the qualitative behavior of the system in both transient cases. As for the system response, it was found that it is contingent on the activation time of the PSSs. The differences in reactor coolant system pressure between the two codes were attributed to the critical flow model and simplification of mass and energy balance. Despite PCTRAN’s limitations, it can still provide a reasonable prediction of various reactor parameters such as pressure, mass flow rate, and void fraction during a SBLOCA scenario. It is worth noting that PCTRAN currently employs a bulk approach similar to that of the Modular Accident Analysis Program (MAAP) and MELCOR codes. However, the upcoming version of PCTRAN will include an artificial intelligence–based detection and accident prevention system, as well as different models for different reactor components. Consequently, PCTRAN has the potential to be upgraded to match the system thermal-hydraulic codes of the U.S. Nuclear Regulatory Commission and become more widely used in cybersecurity to safeguard nuclear power plants from cyberattacks.

Multi-objective early-stage design optimization of multifamily residential projects

The aim of this study is to find a building form and plan layout that can be used in the early stages of architectural design, where criteria such as daylight, view, sun-hour, sales area, and cost are optimized according to the different expectations of different housing type users. This study proposes a multi-objective early-stage design optimization for a real estate development project based on the NSGA2 genetic algorithm, considering weighted user preferences for different housing types. The framework is implemented using the platforms Rhino and Grasshopper; Wallacei is used for NSGA2, and Viktor.ai is used to deploy the app. Tested on six sample plots, the model was able to find architecturally optimized results that respond to different user expectations. While the model successfully demonstrated responsiveness to parameters, its focus on Pareto-optimal solutions limited the diversity of unit mixes generated. The model has been tested by professionals on a sample plot and is found to be important for architects and investors to generate ideas at an early stage of architectural design.

Track–bridge interaction effects in the acceleration and displacement response of high-speed railway bridges: Simplified vs refined modelling

The prediction of structural vibrations induced by high-speed trains is crucial for designing bridge structures, as well as for the assessment of the dynamic compatibility between bridges and rolling stock in large railway networks. The computational effort involved in such dynamic compatibility checks is also large. However, obtaining an accurate prediction of the dynamic response is challenging due to numerous uncertain factors still under research. Interaction phenomena like vehicle–bridge (VBI), soil–structure (SSI), and track–bridge (TBI) interactions are crucial but complex to model, given the multitude of input parameters and the computational cost required. Therefore, the choice of a modelling approach for simulating the dynamic response of a train crossing a bridge will depend on the focus of analysis. For the purpose of sensitivity analyses – typical in early design stages –, compatibility checks (screenings), and also in non-deterministic analyses, computational cost becomes crucial. Consequently, for practical purposes interaction mechanisms are often simulated by means of simplified and conservative approaches, usually aligned with some design code recommendations. Moreover, traditional physical models, where the problem is idealised as a beam traversed by constant moving loads (travelling load model, TLM), have been commonly employed for such purposes. However, they neglect the load distributive effect of the track on the vehicle axle loads, which has proven to be relevant and beneficial, especially for short bridge spans. The main purpose of this work is thus to investigate the influence of the load spreading effect exerted by the ballasted track on the displacement and acceleration response of single-track, simply-supported (S-S) railway bridges of short-to-medium span lengths under operating conditions, since these structures are prone to experience inadmissible vibration levels under more demanding traffic conditions. A comprehensive analysis of several simplified approaches proposed by regulations and researchers is performed, plus a subsequent comparison vs. a finite element (FE) strategy to consider TBI in a refined manner. Conclusions about the adequacy of the simplified approaches are provided, along with a new data-driven formula for the prediction of the vertical displacement response in resonant conditions, that can be exploited to reduce significantly the computational effort.

Mind the gap: Facilitating early design stage building life cycle assessment through a co-production approach

Despite the transition towards a circular economy (CE) being a significant element in achieving the decarbonisation of the built environment, a clear and common pathway to applying CE principles to building design is still lacking in both industry practice and academia. The integration of Building Information Modelling (BIM) and Life Cycle Assessment (LCA) has the potential to enable the identification of feasible pathways to increase circularity. This study aims to investigate its practical use to facilitate the application of circular economy principles at the early stage of building design via using LCA-based BIM plugins. Within this aim, the paper centres on a co-production approach and presents a gap analysis by identifying gaps in knowledge and implementation as well as addressing the pressing needs of the current practice in the UK. A series of semi-structured interviews with expert practitioners in the field were conducted for data collection, contributing to the following phases of the co-production by allowing for an in-depth investigation and reflection of the practice. The findings have revealed that: (a) there is still an insufficient level of contextual awareness and readiness in the implementation of CE principles in the built environment and LCA understanding and (b) the adoption of BIM at the early stages of building design is still limited in the current practice; BIM models with sufficient level of data details and quality to enable circularity assessment are rarely produced. Thus, the paper highlights the need for enabling mechanisms, including the introduction of legislative instruments, the involvement and commitment of the industry and key stakeholders, the support for training and skills improvement, and the establishment of effective communication and implementation process management frameworks. Future research agenda points to the need of formulation of a BIM protocol to enable integration of BIM and LCA to promote CE principles in the building design process.

Reliability, Availability, and Maintainability Assessment of a Mechatronic System Based on Timed Colored Petri Nets

The mechatronic industry is currently subject to huge changes challenging it to offer products matching individual customer requirements at competitive prices. The design of such products calls for sophisticated and complex components integration following different technologies. Since we are on the cusp of the Fourth Industrial Revolution, in which the world of mechatronic production, network connectivity, the Internet of Things, and cyber-physical systems are correlated, the complexity of these systems increases exponentially, and we are talking about advanced mechatronic systems. To assist these changes, various methods, sweeping all project phases, are used by business houses. Predictive dependability assessment in the earlier design stage is considered a powerful metric used to evaluate the performances of different kinds of mechatronic products before the production phase. Altogether, dependability analysis ties the design directly to the desired functionality, operability, and integrity of the system. This paper explores an approach to assessing the dependability attributes, reliability, availability, and maintainability (RAM), of repairable mechatronic systems based on timed colored Petri nets and a Monte Carlo simulation, integrating simultaneously diverse components technologies: mechanical, electronic, and software. The proposed approach is tested taking the case of a regenerative braking system. The methodology appears to be efficient for evaluating predictive RAM indicators (MTTFF, MTTR, MTBF…) for the whole system and for each individual component separately.

Effects on the design of aeronautical fuel cell systems by inclusion of reliability requirements

The change towards carbon neutrality in air traffic involves a huge reduction of greenhouse gas emissions. This goal is beyond reach by the step wise improvement of conventional technologies. Hence, at present a solution which gains much of attraction are electric motors and electric aircraft systems in combination with fuel cells which can be run by green hydrogen. For a holistic comparison of various concepts the consideration of reliability aspects is required even at an early stage of design. In the scope of this work methods from reliability and safety engineering will be introduced and set in context of aeronautical fuel cell systems. On that basis the consequences arising by the requirement of redundancy are investigated on a system level approach. For this purpose, a model of an aeronautical fuel cell system will be set up in order to simulate a generic flight envelope at stationary points. The fuel cell system is chosen to be central-monolithic and its components are sized for the propulsion of a regional aircraft. With the aid of the system simulation, various failure scenarios are investigated from which mitigation strategies can be derived. Finally, the baseline design will be improved in terms of redundancy in order to last in a generic failure scenario. A comparison between the baseline and improved design shows that the additional redundancy comes with the cost of 4.6% weight increase and a 2.5% drop in cruise efficiency.

Design optimization of an assisted living facility to improve summer thermal comfort in warming climates

Assisted living facilities with optimal summer thermal comfort are necessary to ensure improved quality of life for the older individuals in warming climates. Older individuals are exposed to higher mortality risks during periods of excessive heat. This study aims to identify and optimize key design variables for a passive house certified assisted living facility in Belgium with high comfort expectations using EnergyPlus to improve indoor thermal comfort during extreme climates. The sensitivity analysis used the Standard Regression Coefficient method with Latin Hypercube Sampling for eighteen design variables under four categories: layout, envelope, operation, and system. The analysis identified flat roof and external floor insulation as the most influential parameters, whereas lighting gain and cooling setback temperature were the least influential parameters. Furthermore, optimizing the reference building with the most sensitive design variables using a genetic algorithm based on the NSGA-II method found ideal configurations that would ensure minimum thermal discomfort hours during extreme summers. The study findings provide an evidence-based approach for building engineers and designers for early-stage design of assisted living facilities that maintain optimal comfort in mixed humid climates of Europe.

Assessment of a Simplified Methodology for Preliminary Blast-Resistant Design of Insulated Precast Concrete Wall Panels

Abstract A Blast loading history can be represented by the peak pressure value and the impulse. Combinations of pressure and impulse of various blast loading scenarios can be collected to draw a pressure-impulse (P-I) curve that corresponds to a level of damage of a blast-resistant structural component. The P-I curve is typically used for a preliminary design or assessment of blast resistance structural components. Generating a P I curve for a given structural component and level of protection requires repeatedly ru nning a single degree of freedom system (SDOF) model, which can be tedious for early design stages. Hence, a simplified approach (i.e., the normalization approach) was utilized to promptly generate the P- I curve for insulated precast concrete wall panels, which relies on shifting a control P I curve using normalization factors. The generated P-I curves using the normalization approach are validated with the traditional SDOF approach curves; 95% of the examined insulted panel configurations have an error between +/-7%. As a result of the reached low error percentages, a spreadsheet- design tool was developed using this approach. The tool can further enable rapid evaluation of the performance of insulated precast concrete panels under blast loading during the preliminary design phase.

Methods and tools to address GHG emissions in the early design stage of building renovations: A state-of-the-art review

Methods and tools to address GHG emissions in the early design stage of building renovations: A state-of-the-art review

Investigating social and environmental hotspots throughout the lifecycle of product-service systems in the early design stages

Product-Service Systems (PSS) have been recognized as potential game-changers for advancing sustainability. However, the sustainability of a PSS over traditional products and services is not automatic; it requires careful, intentional design. Despite a decade's progress in relevant literature, early-stage design assessment of a PSS – particularly from a life cycle standpoint and considering the social sustainability dimension – remains underexplored. This study introduces a framework for early-stage identification and analysis of potential environmental and social impacts within a PSS's life cycle to aid in decision-making and guide towards sustainable solutions. The framework's hotspot analysis, which combines life cycle assessment techniques, aims to pinpoint life cycle stages most susceptible to significant environmental and social impacts. Drawing on existing literature and expert evaluations, this approach offers designers preliminary insights into potential impacts, establishing a groundwork for comprehensive life cycle analysis once more detailed information on products, services, and organizational structures becomes available. The hotspot analysis not only addresses the lifecycle view of a PSS but also places emphasis on the oft-neglected social dimension of sustainability, marking an area ripe for further study. By supporting decision-making in the early design phase and encouraging scrutiny of various PSS concepts, this approach promotes the cultivation of sustainably-designed solutions.

A Simple Method for Identifying the Natural Frequency of a Micro Satellite with a Primary Structure Made of Aluminum Alloy

Microsatellites must survive severe mechanical conditions during their launch phase. Usually, the structural design of a micro satellite is performed using the internal stress analysis and the natural frequency analysis, which are based on a finite element method (FEM). The validity of this structural design is evaluated through vibration tests. In an early stage of development, which has a FEM model of a satellite in the process of creation, presumption of the minimum natural frequency of a satellite may be difficult. In this study, a simple method for determining the longitudinal and lateral minimum natural frequencies of microsatellites during the ascent phase was clarified. The structure of the microsatellites used in this research is made of aluminum alloy, and they have a monocoque structure. The Young’s modulus and moment of inertia of area used to calculate the minimum natural frequencies were determined using the area ratio of the monocoque structure to the entire satellite. When the method proposed in this study is used, the calculated values agree with the vibration-tested values within 10%. In particular, in the case of W6U-type satellites, the two agree within a range of approximately 2% in the longitudinal direction and approximately 5% in the lateral direction. In the early stages of a satellite structure design when a FEM cannot be created, the proposed method will work effectively as the method of determining the minimum natural frequency. In order to simplify the process of microsatellites development, this paper describes a practical estimation method of the minimum natural frequency for microsatellites.