A design framework for absorption and diffusion panels with sustainable materials

2021 ◽  
Vol 263 (4) ◽  
pp. 2207-2218
Author(s):  
Jonathan Dessi-Olive ◽  
Timothy Hsu

Architectural acoustics has not traditionally had unified design methods that specify acoustical performance, visual appearance, and sustainable material selection, leading to underperforming products that contribute to a waste stream of petro-chemical foam and fiberglass materials. The evolution of design, materials, and manufacturing techniques in recent years has created new opportunities to reimagine acoustic diffusers and absorbers. Previous work by the authors have demonstrated a unifying framework for design and collaboration in architectural acoustics. The framework uses visually-driven computational design method inspired by shape grammars that generate a wide range of acoustic phase grating diffuser arrays that display unique visual and performative qualities. Simulation and evaluation metrics to assess the complexity of each design are rated in terms of their diffusion and absorption coefficients and a visual aesthetic coefficient. This paper extends the framework to include digital fabrication protocols and sustainable material specifications - including the use of fungi-based materials. Built prototypes demonstrate an expanded acoustic design space that gives acousticians the potential to create custom diffuser shapes with precise acoustical response. The innovative combination of computational design methods and sustainable fabrication protocols will be discussed, and the acoustic properties of arrays will be evaluated and compared to simulations of corresponding designs.

Author(s):  
Wei Li ◽  
Daniel A. McAdams

As the advantages of foldable or deployable structures are being discovered, research into origami engineering has attracted more focus from both artists and engineers. With the aid of modern computer techniques, some computational origami design methods have been developed. Most of these methods focus on the problem of origami crease pattern design — the problem of determining a crease pattern to realize a specified origami final shape, but don’t provide computational solutions to actually developing a shape that meets some design performance criteria. This paper presents a design method that includes the computational design of the finished shape as well as the crease pattern. The origami shape will be designed to satisfy geometric, functional, and foldability requirements. This design method is named computational evolutionary embryogeny for optimal origami design (CEEFOOD), which is an extension of the genetic algorithm (GA) and an original computational evolutionary embryogeny (CEE). Unlike existing origami crease pattern design methods that adopt deductive logic, CEEFOOD implements an abductive approach to progressively evolve an optimal design. This paper presents how CEEFOOD — as a member of the GA family — determines the genetic representation (genotype) of candidate solutions, the formulation of the objective function, and the design of evolutionary operators. This paper gives an origami design problem, which has requirements on the folded-state profile, position of center of mass, and number of creases. Several solutions derived by CEEFOOD are listed and compared to highlight the effectiveness of this abductive design method.


Author(s):  
Anand P. Deshmukh ◽  
Danny J. Lohan ◽  
James T. Allison

Physical testing as a technique for validation of engineering design methods can be a valuable source of insights not available through simulation alone. Physical testing also helps to ensure that design methods are suitable for design problems with a practical level of detail, and can reveal issues related to interactions not captured by physics-based computer models. Construction of physical and testing of physical prototypes, however, is costly and time consuming so it is not often used when investigating new design methods for complex systems. This gap is addressed through an innovative testbed presented here that can be reconfigured to achieve a range of different prototype design properties, including kinematic behavior and different control system architectures. Thus, a single testbed can be used for validation of numerous design geometries and control system architectures. The testbed presented here is a mechanically and electronically reconfigurable quarter-car suspension testbed with nonlinear elements that is capable of testing a wide range of both optimal and sub-optimal design prototypes using a single piece of equipment. Kinematic suspension properties can be changed in an automated way to reflect different suspension linkage designs, spring and damper properties can be adjusted in real time, and control system design can be changed easily through streamlined software modifications. While the specific case study is focused on development of a reconfigurable system for validation of co-design methods, the concept extends to physical validation using reconfigurable systems for other classes of design methods.


Author(s):  
William R. Binder ◽  
Christiaan J. J. Paredis

In this paper, we introduce a research method for comparing computational design methods. This research method addresses the challenge of measuring the difference in performance of different design methods in a way that is fair and unbiased with respect to differences in modeling abstraction, accuracy and uncertainty representation. The method can be used to identify the conditions under which each design method is most beneficial. To illustrate the research method, we compare two design methods for the design of a pressure vessel: 1) an algebraic approach, based on the ASME pressure vessel code, which accounts for uncertainty implicitly through safety factors, and 2) an optimization-based, expected-utility maximization approach which accounts for uncertainty explicitly. The computational experiments initially show that under some conditions the algebraic heuristic surprisingly outperforms the optimization-based approach. Further analysis reveals that an optimization-based approach does perform best as long as the designer applies good judgment during uncertainty elicitation. An ignorant or overly confident designer is better off using safety factors.


2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Karen Scarlette Sanhueza ◽  
Christopher Nikulin

Purpose The purpose of this paper is to address the emerging need to map knowledge and information with a novel classification, suitable to have a clear and integrated overview of the design method, models and techniques from both the sides of product and process. The proposed classification allows to understand main relevance of different design methods, models and techniques according their characteristic and also level in where company usually applied. Design/methodology/approach The authors decided to structure the research into three steps: from the analysis of background literature, in order to draw the main evidences for the development of a novel classification, to their application. First, the papers search related to collect the different methods used in literature. Second, paper characterization which aims to understand main traits and usefulness of design methods, models and tools. Third, the assessment of design methods, models and tools according proposed classification. Findings Each method, model or technique would be more useful according to the context in which is applied. Most of methods and modes can be continuously improving, considering different sub-classification or complement each other, striving to compensate to the extent possible for weakness in any one of the approaches. Research limitations/implications The proposed classification did not deliver absolute results in every analyzed model or techniques, it delivered a wide range of possibilities in every sub-classification, thus the engineers get multiple options to choose depending on its main goal or the available resources. Originality/value The author’s proposal aims at filling a classification gap in the design method literature, which has to plausible in use. The different alternatives can be represented according to a scalable and hierarchical logic embedding also a more structured evaluation of the methods and tools in practice.


Author(s):  
Wentai Zhang ◽  
Zhangsihao Yang ◽  
Haoliang Jiang ◽  
Suyash Nigam ◽  
Soji Yamakawa ◽  
...  

Abstract We propose a data-driven 3D shape design method that can learn a generative model from a corpus of existing designs, and use this model to produce a wide range of new designs. The approach learns an encoding of the samples in the training corpus using an unsupervised variational autoencoder-decoder architecture, without the need for an explicit parametric representation of the original designs. To facilitate the generation of smooth final surfaces, we develop a 3D shape representation based on a distance transformation of the original 3D data, rather than using the commonly utilized binary voxel representation. Once established, the generator maps the latent space representations to the high-dimensional distance transformation fields, which are then automatically surfaced to produce 3D representations amenable to physics simulations or other objective function evaluation modules. We demonstrate our approach for the computational design of gliders that are optimized to attain prescribed performance scores. Our results show that when combined with genetic optimization, the proposed approach can generate a rich set of candidate concept designs that achieve prescribed functional goals, even when the original dataset has only a few or no solutions that achieve these goals.


Author(s):  
Cosima du Pasquier ◽  
Pascal Koller ◽  
Tino Stankovic ◽  
Kristina Shea

Abstract With advances in 3D printing and digital fabrication an opportunity is presented to realize highly customized designs whose shape can change and adapt to facilitate their functionality. A computational design method to determine the configuration of 2D pneumatic shape morphing lattices using a direct search method is implemented and assessed. The method is tested using a Kagome unit cell lattice structure, which is particularly well suited for shape morphing. To achieve shape change, beams are replaced by linear actuators such as those found in pneumatic 4D printing, whose number and placement are optimized to replicate a given target shape. The actuator placement and deformation accuracy are given for four main curvature changes: linear, convex, concave and the transition from one to the other. The results are assessed in terms accuracy of deformation and computational effort. It is shown that the method proposed produces structures that can replicate complex shape changes within 1% of the desired shape. Reducing the number of actuators for robustness purposes is shown to affect the results minimally.


Author(s):  
Sarah Oman ◽  
Michael Koch ◽  
Irem Y. Tumer ◽  
Matt Bohm

In the early stages of the design process, there is a need to provide designers with tools to assess risks and possible failures so as to avoid costly redesigns, comply with established safety measures and to promote innovation throughout the design process. Recently, various methods have been proposed in research to accomplish such tasks, including the Risk in Early Design (RED) and the Function Failure Design Method (FFDM). This paper proposes a method for examining the utility of such failure-based computational design methods. Validation is accomplished by analyzing products with a known history of failure, decomposing these products into functional representations and performing both RED and FFDM analyses on these models to see how closely such methods are able to correctly identify the real-world failures. The goal of this work is to determine the effectiveness of both the RED and FFDM methods in order to suggest improvements for both methods. The results provide insight on the verification methodology in addition providing to prescriptive methods to increase the usefulness of early stage failure and risk assessment techniques.


2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Shamanth Hampali ◽  
Anoosha Pai S ◽  
G. K. Ananthasuresh

Abstract This paper is concerned with a compliant-hinge mechanism that can provide a wide range of torque-angle profiles. The mechanism consists of thin-walled open-section shells that are subjected to combined twisting and bending. A pair of open-section shells is so arranged as to get a large rotation about a virtual axis with high stiffness along other axes. A replaceable cam-like guideway regulates the bending of the open-section shells as they twist, thereby generating the desired torque profile. An energy-based, graphical, and computational design method is formulated to obtain the guideway profile for a specified torque profile. A physical prototype is constructed for an assistive chair for the elderly to demonstrate the variable-torque output and the efficacy of the hinge.


Author(s):  
Wei Li ◽  
Daniel A. McAdams

As the advantages of foldable or deployable structures are being discovered, research into origami engineering has attracted more focus from both artists and engineers. With the aid of modern computer techniques, some computational origami design methods have been developed. Most of these methods focus on the problem of origami crease pattern design—the problem of determining a crease pattern to realize a specified origami final shape, but do not provide computational solutions to actually developing a shape that meets some design performance criteria. This paper presents a design method that includes the computational design of the finished shape as well as the crease pattern. The origami shape will be designed to satisfy geometric, functional, and foldability requirements. This design method is named computational evolutionary embryogeny for optimal origami design (CEEFOOD), which is an extension of the genetic algorithm (GA) and an original CEE. Unlike existing origami crease pattern design methods that adopt deductive logic, CEEFOOD implements an abductive approach to progressively evolve an optimal design. This paper presents how CEEFOOD—as a member of the GA family—determines the genetic representation (genotype) of candidate solutions, the formulation of the objective function, and the design of evolutionary operators. This paper gives an origami design problem, which has requirements on the folded-state profile, position of center of mass, and number of creases. Several solutions derived by CEEFOOD are listed and compared to highlight the effectiveness of this abductive design method.


Author(s):  
Warren Brown

This paper details further progress made in the PVRC project “Development of Improved Flange Design Method for the ASME VIII, Div.2 Rewrite Project” presented during the panel session on flange design at the 2006 PVP conference in Vancouver. The major areas of flange design improvement indicated by that project are examined and the suggested solutions for implementing the improved methods into the Code are discussed. Further analysis on aspects such as gasket creep and the use of leakage-based design has been conducted. Shortcomings in the proposed ASME flange design method (ASME BFJ) and current CEN flange design methods (EN-1591) are highlighted and methods for resolution of these issues are suggested.


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