Parametric Design Research Articles

Personalized Vulnerability Assessment of Customized Low-Rise Wood-Frame Residential Structures under Hurricane Wind Loads: A Flexible Scenario-Based Simulation Approach

Hurricanes are one of the costliest and deadliest weather and climate disasters that impact the United States, largely affecting the residential sector. Residential structures are essential for the health and safety of the community during a hurricane event. However, homeowners typically have to rely on general information and instructions to understand their level of risks. The knowledge of structural vulnerability to hurricanes at the individual residential building level is often limited, which hinders personalized disaster preparation and mitigation decision-making. To this end, a vulnerability assessment method is proposed for individual homeowners to create customized finite-element models that quantify wind damage of low-rise wood-frame residential structures under various scenarios using ANSYS 2020 R1 parametric design language. A case study was conducted to test the proposed methodology and investigate prevailing failure modes under different structural characteristics and wind scenarios. Specifically, the impacts of roof framing features and previous exposure to environmental conditions on the potential damage of residential buildings under hurricane wind loads were studied. Analysis results, including the percentage of failed sheathing, nailed connections and framing members, are used to inform personalized mitigation recommendations. The proposed customized vulnerability assessment may increase homeowners’ situational awareness of disasters and promote rational retrofitting decisions.

A holistic digital workflow methodology to shifting towards net zero energy urban residential buildings in a semi-arid climate

Given the looming threats of climate change and the rapid worldwide urbanization, it is a necessity to prioritize the transition towards a carbon-free built environment. This research study provides a holistic digital methodology for parametric design of urban residential buildings with regard to the Mediterranean semi-arid climate zone of Morocco in the early design phase. The morphological parameters of the urban residential buildings, namely the buildings’ typology, the distance between buildings, the urban grid’s orientation, and the window-to-wall ratio, are evaluated in order to identify the key combinations of passive and active solar design strategies that determine the high energy performing configurations, based on the introduced Energy Performance Index (EPI), which is the ratio between solar BIPV production to maximum available installed BIPV capacity and the normalized thermal energy needs. Through an automated processing of 2187 iterations via Grasshopper, we simulate daylight autonomy, indoor thermal comfort and solar rooftop photovoltaic and building integrated photovoltaic (BIPV) energy potential. Then, we analyze the conflicting objectives of energy efficiency measures, active solar design strategies, and indoor visual comfort in the decision-making process that supports our goal of getting closer to net zero urban residential buildings. The digital workflow showed interesting trends in reaching a balanced equilibrium between performance metrics influenced by the contrasting impact of solar exposure on indoor daylight autonomy and thermal energy demand. Furthermore, the study's findings indicate that it is possible to achieve an annual load match exceeding 66,56 % while simultaneously ensuring an acceptable visual indoor comfort (sDA higher than 0.4). The findings also highlight the important role of the BIPV system in shifting towards the net zero energy goal, by contributing up to 30 % of the overall solar energy output and covering up to 20 % of the yearly self-consumption. Moreover, the energy balance evaluation on an hourly basis indicates that BIPV system notably enhances the daily load cover factor by up to 5.5 %, particularly in the case of slab SN typology, throughout the different seasons.Graphical representations of the yearly, monthly and hourly load matches and the hourly energy balance of the best performing configurations provide a thorough understanding of the potential evolution of the urban energy system over time as a result of the gradual integration of active solar electricity production.

Computer Aided Thermal Analysis of the FSW Tool Geometry

The thermal analysis will be realised in a Computer Aided Parametric Design program for three tools with different pin geometries to determine the transfer and distribution of the thermal energy produced during the process and to observe the influence of the pin geometry has on the distribution. Due to the fact that the joining process can be done at a lower temperature than the melting point of the material certain steps must be followed prior and correct selection of the machine’s parameters. Information on the parameters for specific materials and the preparation of the base material are readily available but considering the method of producing the thermal energy necessary for the process the quality of the weld is highly influenced by preheat time (of the material and tool), room temperature, cooling of the tool or work piece if the machine is equipped with such a configuration. We will observe in this study the effect of tool pin geometry over dwell time for reaching a uniform temperature of the tool in the shortest amount of time. The parameters used for the acquiring the data needed for the thermal analysis regarding tool material are tungsten carbide and the material of the plates will be aluminium 1200. The paper’s subject will be the realisation of a thermal analysis of the FSW (Friction Stir Welding) tools.

An integrated structure of air spring for ships and its strength characteristics

Abstract The increasing demand for the impact resistance of ships entails the excellent impact resistance and deformability of air spring (AS) for ships under high internal pressure. However, an AS of traditional structure is difficult to satisfy such new demand since it is designed with only 10 mm maximum deformation under high internal pressure and strong impact. For this reason, an integrated structure of filament winding reinforced bellows is proposed to ensure the structural strength at the connection of AS bellows and flanges under strong impact and high internal pressure. On this basis, a parameterized design of integrated bellows strength is explored, and we analyzed how the strength of the bellows was affected by the parameters of geometrical structure, material features, and filament winding. As proved in tests, the integrated structural design of the bellows could ensure the strength of AS under strong impact and high internal pressure, and the test result perfectly matches with the calculated strength of the integrated bellows as well as the optimized design.

The response of diagrid structures to fire

The diagrid structural system has seen significant uptake in medium to high rise buildings because of the architectural and resource advantages that it provides. These arise mainly as a result of flexibility in the topology that this particular structural solution provides. However, as a result of the way in which diagrids carry both horizontal and vertical loading, the diagrid structure itself may be susceptible to fire in ways which are not immediately obvious on the basis of our understanding of more traditional rectilinear construction forms. This study addresses this to improve our understanding of diagrid structures' response to fire. A comprehensive structural analysis on 45 fire load cases is conducted, considering different fire locations and sizes, using parametric design tools and finite element analysis software. The results provide valuable insights into the load redistribution and collapse mechanisms of diagrid structures in fire conditions.

An integrated framework for residential layout designs: Combining parametric modeling, neural networks, and multi-objective optimization for outdoor activity space optimization

The quality of life of residents and community vitality is significantly enhanced by outdoor activity spaces within residential areas. Existing residential layout designs primarily focus on a restricted set of predefined layouts and most outdoor evaluation indices are limited to thermal comfort, thereby leading to an incomplete evaluation system. Furthermore, there is a scarcity of studies offering a comprehensive design process, from parameterized generation to performance evaluation. As such, there is a pressing need for an all-encompassing design framework that investigates a broad array of layout possibilities while providing multidimensional evaluations based on diverse metrics, thereby augmenting the accuracy and intelligence of residential layout designs.This research introduces a building layout generation framework that integrates parametric modeling (PD), neural network modeling (ANN), and multi-objective optimization (MOO) methods. The framework utilizes parametric design methods to construct a geometric model that adheres to building codes. Following this, it builds separate neural network models for three key metrics: sky view factor (SVF), sunshine duration, and noise, this approach is aimed at accelerating the evaluation process. This alternative model serves as the objective function for multi-objective optimization, identifying the optimal building layout that balances multiple metrics. Additionally, the framework utilizes the ideal point method to optimize the final Pareto solution set, thereby informing designers' and planners' program selections.Case studies of this framework indicate that the residential layouts generated can adhere to building codes while effectively balancing the three crucial metrics. Relative to the conventional modeling-evaluation process, this framework augments efficiency substantially. The design framework presented herein will offer comprehensive decision support for policy makers to optimize residential layout designs, further fostering the harmonious coexistence of people and cities, while advancing intelligent building design and sustainable urban development.

A novel thermomechanical model for predicting interfacial stresses in flexible hybrid laminate

Triggered by the growing needs for photoelectric conversion and optical interconnections, flexible optoelectronics have recently attracted a surge of interest. Flexible hybrid laminates are promising components of these devices owing to their high performance and flexibility. However, the thermomechanical mismatch of heterostructures usually induces interfacial stresses and resultant failures, particularly for multilayer structures with soft polymeric substrates. The interfacial stresses in flexible laminates remain a challenging matter to be understood distinctly. Herein, the interfacial stresses are investigated via a representative case composed of hard and soft hybrid laminate under nonuniform temperature. By introducing nonuniform shear strain in the thickness direction of bond layer, and nonuniform temperature changes of multilayer simultaneously, a novel analytical model is developed to describe the interfacial stresses with considering adjusted interfacial compliances for the bond layer with varying thicknesses. Our analytical expressions are suitable for different interfacial compliances and a trilinear approximation is verified by the finite element method (FEM) for the adhesive layers with different thicknesses, and comparative analyses were carried out with the existing literatures. The characteristics of the shear stresses are quantitatively illustrated under different temperature variations, elastic moduli and geometrical dimensions. Based on above the vital influencing factors, the mitigating strategies for shear stress are proposed to decrease the interfacial damage. By optimizing key parametric designs, the model and analysis of interfacial stresses could be useful for characterizing the interfacial thermal stress of rigid-flexible films, and enhancing the mechanical stability of heterogeneous multilayers.

Extended melt‐conveying models for single‐screw extruders: Integrating domain knowledge into symbolic regression

AbstractThe literature provides several analytical approximation methods for predicting the flow of non‐Newtonian fluids in single‐screw extruders. While these are based on various flow conditions, they were developed mostly for extruder screws with standard geometries. We present novel analytical melt‐conveying models for predicting the flow and dissipation rates of fully developed flows of power‐law fluids within three‐dimensional screw channels. To accommodate a broad range of industrial screw designs, including both standard and high‐performance screws, the main intention of this work was to significantly extend the scope of existing theories. The flow equations were first rewritten in a dimensionless form to reduce the mathematical problem to its dimensionless influencing parameters. These were varied within wide ranges to create a set of physically independent modeling setups, the flow and dissipation rates of which were evaluated by means of a finite‐volume solver. The numerical results were then approximated analytically using symbolic regression based on genetic programming. To support the regression analysis in finding accurate solutions, we integrated domain‐specific process knowledge in the preprocessing of the dataset. We obtained three regression models for predicting the flow and dissipation rates in melt‐conveying zones and tested their accuracy successfully against an independent set of numerical solutions.Highlights Flow of power‐law fluids in three‐dimensional screw channels Identification of independent influencing parameters by dimensional analysis Numerical parametric design study for a broad range of industrial applications Integration of domain knowledge in symbolic regression Surrogate models derived from numerical simulation results

A Parametric Design Study of Natural-Convection-Cooled Heat Sinks

Effective natural-convection-cooled heat sinks are vital to the future of electronics cooling due to their low energy demand in the absence of an external pumping agency in comparison to other cooling methods. The present numerical study was carried out with ANSYS Fluent and aimed at identifying a more-effective fin design for enhancing heat transfer in natural convection applications for a fixed base-plate size of 100 mm × 100 mm under an applied heat flux of 4000 W/m2. The Rayleigh number used in the present study lied within the range of 2.6 × 106 to 4.5 × 106. Initially, a baseline case with rectangular fins was considered in the present study, and it was optimized with respect to fin spacing. This optimized baseline case was then validated against the semi-empirical correlation from the scientific literature. Upon good agreement, the validated model was used for comparative analysis of different heat sink configurations with rectangular, trapezoidal, curved, and angled fins by constraining the surface area of the heat transfer. The optimized fin spacing obtained for the baseline case was also used for the other heat sink configurations, and then, the fin designs were further optimized for better performance. However, for the angled fin case, the optimized configuration found in the scientific literature was adopted in the present study. The proposed novel curved fin design with a shroud showed a 4.1% decrease in the system’s thermal resistance with an increase in the heat transfer coefficient of 4.4% when compared to the optimized baseline fin case. The obtained results were further non-dimensionalized with the proposed scaling in terms of the baseline case for the two novel heat sink cases (trapezoidal, curved).

Round bar notch shape optimization for tensile stress concentration testing

Abstract Notched structures in machine parts for several reasons cause discontinuity and stress concentration. It is essential to optimize these stress concentrations in notched parts. This study determined the best notch shape by creating different notch shapes by keeping two key points fixed on the spline curve in the notched region. This paper involves optimizing the shape of a fillet in a notched tension bar. An optimal shape was aimed to minimize the notch factor without causing yield anywhere in the bar by parametrically controlling the spline of the fillet via ANSYS parametric design language code. Optimal shapes of B-spline curves were obtained for round bars subject to axial tension loadings. Changing the code can also be used for bending or combined loading conditions other than tensile loading.

Parametric design tools and how to take advantage of it in 3D sculptural design

The design was distinguished in Late Twenty-First Century With new and new methods Through which the ability to adapt all technical media in the formation of two-dimensional and three-dimensional figures and shapes was achieved .Which led to the emergence of endless sets of design ideas characterized by the heterogeneity of design forms and design solutions that preceded it. The designer could not access these creations in various architectural and artistic fields only through computer programs, especially those related to the activation of mathematical logic and what is known as algorithms in the formation and construction of the form, which led to the emergence of the "parametric direction" and the problem of research is summarized in the extent of the influence of parametric on the design The research aims to shed light on the emergence of parameter to shed light on the concept of parameter and its tools the research takes the approach (descriptive and analytical) spatial boundaries of some countries of the world, for example, but not limited to since the appearance of parameter until now, and the researcher offered a formative reading of some objects Museum parametric sculpture and a formative reading of some parametric sculptural objects in the open air One of the results of the research is that the sculptor, through the use of parametric, is able to design works for display internally in facilities or externally in squares and gardens, and that the parametric artist has knowledge of the elements that must be taken into account when designing models for museum display or garden display and outdoors, and the researcher recommends the need to pay attention to contemporary techniques in the field of Arts and direct scientific research in the field of Arts in general and sculpture in particular to discuss recent developments and discoveries in the fields of design and implementation of models in different countries of the world.

Computer- Aided Design in the Aerospace Industry

Computer-Aided Design, a multifunctional software application employed by designers and engineers, has altered the way products are conceived, visualized, developed, tested, and manufactured. Supporting a wide range of design types, to name a few: 2D drafting, 3D modeling, parametric design, surface modeling, and solid modeling, the reliance of industries on this software has risen inexplicably to meet the needs of its consumers or to yield a desired product. Here, the aerospace industry is no stranger.

Exploring Architectural Shapes Based on Parametric Shape Grammars: A Case Study of the “Three Lanes and Seven Alleys” Historic District in Fuzhou City, China

With the development of information technology, the introduction of information technology into architectural modelling and façade design and the systematic definition of historic districts is a problem that the architectural industry continues to explore and pursue. As a shape-based and self-defining generation rule, shape grammar provides significant help in the process of the automatic generation of architectural shapes to obtain design results that meet the requirements of the original historic district. Based on the simple combination of the application of shape grammar in architectural design, combined with the field investigation method, the representative buildings in the “Three Lanes and Seven Alleys” historic district are investigated and understood in detail, and the corresponding shape grammar rules are established. The courtyard types of the historic district are divided into: “” shape, “T” shape, “=” shape, “” shape, “” shape, “” shape, “” shape, “U” shape, “” shape, and garden. In detail, the façade components include the entrance, patio, main seat, wings, cloister, pavilion, etc. The elements of its façade include saddle walls, grey sculptures, carved stones, grey tiles, wooden grilles, wooden railings, wood grain flowers, etc. On this basis, parametric design is introduced to convert the design syntax into parametric programs. Grasshopper in Rhino is mainly used to visualize and simulate the regulation, and finally, achieve the purpose of automatically generating the architectural shape and façade of the “Three Alleys and Seven Alleys” historic district by adjusting its parameters.

Parametric Integration of Multiple Criteria from a Cultural Heritage Perspective

Parametric design is a versatile decision-making methodology that allows multi-criteria optimization. However, it is not as common for addressing aspects such as the cultural heritage of a given community. In this context, qualitative research proposes linking a cultural heritage classification with parametric design algorithms that include a stage of “design thinking” methodology, which culminates in community validation. This paper aims to demonstrate the potential of parametric and low-tech design as a multi-criteria decision strategy. Algorithms were developed with the mechanical properties of a given material, with meteorological information as input data, geometry as response, and with a simultaneously integrated multi-criteria decision-making process to improve the design. Most algorithms take as input variables such as size, function, or geometry and, as output, the structural material that best fits them, but not the opposite. This methodology was tested on a case study with the Misak community in Colombia, using Guadua (Guadua angustifolia), a subfamily of the bamboo, but which is little used. These criteria provided multiple design alternatives that were constantly debated to adjust and test the parameters of the prototype. The principal outcome is that an existing cultural heritage classification allows for the parametric model’s generalization ability.

A practical decision process for building façade performance optimization by integrating machine learning and evolutionary algorithms

ABSTRACT With the development of building design parameterization, more and more designers want to explore design options that optimize performance. However, the enormous time and costs that accompany optimization exploration are often beyond the reach of design practices. The application of machine learning in the construction field in recent years has offered potential solutions. Training predictive models through machine learning enables the rapid assessment of built environment performance and thus brings the optimization process closer to reality. In this paper, we mainly developed a process that integrates machine learning predictive model and multi-objective algorithms to achieve rapid evaluation and obtain optimal solutions. Using façade design as a case study, we demonstrate the design decision process with regard to the optimized solutions. The results showed that, through the proposed visual design decision process, designers can easily compare the performance and design appearance of different solutions and make informed decisions. In addition to saving 87% of time compared to the traditional simulation process, the integrated process also introduced the predictive model, which can achieve optimization exploration in one day. These results all demonstrate that the use of an integrated approach boasts considerable time advantages and potential feasibility in design practice.

Parametric Design and Prototyping of a Low-Power Planar Biped Robot.

This study proposes a design approach and the development of a low-power planar biped robot named YU-Bibot. The kinematic structure of the robot consists of six independently driven axes, and it weighs approximately 20 kg. Based on biomimetics, the robot dimensions were selected as the average anthropomorphic dimensions of the human lower extremities. The optimization of the mechanical design and actuator selection of the robot was based on the results of parametric simulations. The natural human walking gait was mimicked as a walking pattern in these simulations. As a result of the optimization, a low power-to-weight ratio of 30 W/kg was obtained. The drive system of the robot joints consists of servo-controlled brushless DC motors with reduction gears and additional bevel gears at the knee and ankle joints. The robot features spring-supported knee and ankle joints that counteract the robot's weight and compensate for the backlash present in these joints. The robot is constrained to move only in the sagittal plane by using a lateral support structure. The robot's feet are equipped with low-cost, force-sensitive resistor (FSR)-type sensors for monitoring ground contact and zero-moment point (ZMP) criterion. The experimental results indicate that the proposed robot mechanism can follow the posture commands accurately and demonstrate locomotion at moderate stability. The proposed parametric natural gait simulation-based design approach and the resulting biped robot design with a low power/weight ratio are the main contributions of this study.

A Parametric BIM Framework to Conceptual Structural Design for Assessing the Embodied Environmental Impact

Decisions made in the early design stage have a significant effect on a building’s performance and environmental impact. In practice, a conceptual design is performed by an architect, while a structural engineer begins to work in later phases when the architectural concept has already evolved. However, the geometry and form of a building directly determine the type of structure and applicable materials; therefore, the conceptual design phase gives rise to examining alternative solutions. This paper presents a method for generating alternative structural solutions in the conceptual design phase and examining their embodied environmental impact by integrating parametric design and building information modeling (BIM). Rhinoceros and Grasshopper were used to develop the parametric script, which includes the generation of geometrical variations, the automatic definition of initial cross sections for the load-bearing elements based on in-built structural design approximations, the datasets for embodied environmental impact of the used building materials, the generation of life cycle inventory (LCI), the automatic calculation of life cycle assessment (LCA) results based on the geometry, and the conversion of the parametric model into building information model. The method was demonstrated using a case study of 48 different alternative solutions for an unheated warehouse made of steel frames. Based on the results, the areas with the greatest energy impact were identified. The case study analysis also illustrated that the applied cross section may have a significant effect on the impact categories. The results draw attention to the complexity of LCA calculations even in the case of a simple structure containing a limited number of variables, where parametric design can serve as an effective tool for a comprehensive environmental impact assessment.

FPGA Design of Transposed Convolutions for Deep Learning Using High-Level Synthesis

Deep Learning (DL) is pervasive across a wide variety of domains. Convolutional Neural Networks (CNNs) are often used for image processing DL applications. Modern CNN models are growing to meet the needs of more sophisticated tasks, e.g. using Transposed Convolutions (TCONVs) for image decompression and image generation. Such state-of-the-art DL models often target GPU-based high-performance architectures, due to the high computational and hardware resource needs of TCONV layers. To avoid prohibitive GPU energy costs, CNNs are increasingly deployed to decentralized embedded autonomous devices, such as Field Programmable Gate Arrays (FPGAs). However, this poses challenges for designing efficient hardware implementations of TCONV layers. This paper presents a parameterized design and implementation of a new TCONV module, which is synthesizable onto FPGAs. It is implemented using the High-Level Synthesis (HLS), through a C++ template to parameterize its functional and non-functional properties. These parameters allow kernel sizes, image sizes, quantization and parallelism to be varied by users. With a systematic exploration in this design space, we find an optimal instance of this TCONV module that achieves 6.25 Giga Outputs per Second (Gout/s) using just 1.53 W of power. We then use our TCONV layer in two neural networks for image decompression and image generation. Image decompression achieves a speed throughput of more than 30K frames-per-second (fps) using only the 16% of resources on average, image generation achieves an energy efficiency of 324 fps/W and outperforms comparable state-of-the-art models by at least 7.3×.

Structural design using reclaimed wood – A case study and proposed design procedure

Applying circular economy principles through the structural reuse of reclaimed wood in new construction can reduce the climate impact of the construction industry. The ability to reuse reclaimed wood products in new structural design is limited by the modern wood industry and design process. This paper describes the implementation of new processes that allow designers to account for variability in the dimension and mechanical properties of reclaimed wood in a case study design-build project on the Cornell University campus in 2022. Dimension variability was approached with a parametric design workflow. The assignment of mechanical property design values to reclaimed wood was approached through species identification, functions that related mechanical properties to specific gravity, and static bending tests. The process based on species identification was sufficient but led to underutilization of structural members. A design method which uses adjusted functions that relate mechanical properties to specific gravity is proposed.

An industry case study using parametric modelling to facilitate Passive House design

A Passive House’s airtight, well-insulated building envelope can lower operating energy use but also increase the possibility of overheating during the summer. The Passive House Planning Package (PHPP) Excel modelling tool for Passive Houses treats the entire structure as a single thermal zone; this simplification may be in part to blame for the instrument’s poor capacity to forecast the risk of overheating. The current study offers new information on two subjects. First, we compare PHPP’s overheating evaluation method to that of the Chartered Institution of Building Services Engineers’ (CIBSE) ‘TM59’ standard, which involves conducting dynamic energy modelling at the room level. Our results support the idea that PHPP underestimates overheating. In the analysed case, glazing solar heat gain coefficient, and air change rate were some of the most crucial factors affecting compliance. Second, we highlight the usefulness of parametric design for compliance.