Free-form Building Research Articles

Direct-write of free-form building blocks for artificial magnetic 3D lattices

By the fabrication of periodically arranged nanomagnetic systems it is possible to engineer novel physical properties by realizing artificial lattice geometries that are not accessible via natural crystallization or chemical synthesis. This has been accomplished with great success in two dimensions in the fields of artificial spin ice and magnetic logic devices, to name just two. Although first proposals have been made to advance into three dimensions (3D), established nanofabrication pathways based on electron beam lithography have not been adapted to obtain free-form 3D nanostructures. Here we demonstrate the direct-write fabrication of freestanding ferromagnetic 3D nano-architectures. By employing micro-Hall sensing, we have determined the magnetic stray field generated by our free-form structures in an externally applied magnetic field and we have performed micromagnetic and macro-spin simulations to deduce the spatial magnetization profiles in the structures and analyze their switching behavior. Furthermore we show that the magnetic 3D elements can be combined with other 3D elements of different chemical composition and intrinsic material properties.

Freeform additive manufacturing by vari-directional vari-dimensional material deposition

PurposeThe purpose of this paper is to propose and demonstrate a new additive manufacturing approach that breaks the layer-based point scanning limitations to increase fabrication speed, obtain better surface finish, achieve material flexibility and reduce equipment costs.Design/methodology/approachThe freeform additive manufacturing approach conceptually views a 3D article as an assembly of freeform elements distributed spatially following a flexible 3D assembly structure, which conforms to the surface of the article and physically builds the article by sequentially forming the freeform elements by a vari-directional vari-dimensional capable material deposition mechanism. Vari-directional building along tangential directions of part surface gives surface smoothness. Vari-dimensional deposition maximizes material output to increase build rate wherever allowed and minimizes deposition sizes for resolution whenever needed.FindingsProcess steps based on geometric and data processing considerations were described. Dispensing and forming of basic vari-directional and vari-dimensional freeform elements and basic operations of joining them were developed using thermoplastics. Forming of 3D articles at build rates of 2-5 times the fused deposition modeling (FDM) rate was demonstrated and improvement over ten times was shown to be feasible. FDM compatible operations using 0.7 mm wire depositions from a variable exit-dispensing unit were demonstrated. Preliminary tests of a surface finishing process showed a result of 0.8-1.9 um Ra. Initial results of dispensing wax, tin alloy and steel were also shown.Originality/valueThis is the first time that both vari-directional and vari-dimensional material depositions are combined in a new freeform building method, which has potential impact on the FDM and other additive manufacturing methods.

Magnetic Characterization of Direct-Write Free-Form Building Blocks for Artificial Magnetic 3D Lattices.

Three-dimensional (3D) nanomagnetism, where spin configurations extend into the vertical direction of a substrate plane allow for more complex, hierarchical systems and the design of novel magnetic effects. As an important step towards this goal, we have recently demonstrated the direct-write fabrication of freestanding ferromagnetic 3D nano-architectures of ferromagnetic CoFe in shapes of nano-tree and nano-cube structures by means of focused electron beam induced deposition. Here, we present a comprehensive characterization of the magnetic properties of these structures by local stray-field measurements using a high-resolution micro-Hall magnetometer. Measurements in a wide range of temperatures and different angles of the externally applied magnetic field with respect to the surface plane of the sensor are supported by corresponding micromagnetic simulations, which explain the overall switching behavior of in part rather complex magnetization configurations remarkably well. In particular, the simulations yield coercive and switching fields that are in good quantitative correspondence with the measured coercive and switching fields assuming a bulk metal content of 100 at % consisting of bcc CoFe. We show that thermally-unstable magnetization states can be repetitively prepared and their lifetime controlled at will, a prerequisite to realizing dynamic and thermally-active magnetic configurations if the building blocks are to be used in lattice structures.

A Development of Pre and Post Processor for Design of Surface System of Free Form Building

A Development of Pre and Post Processor for Design of Surface System of Free Form Building

Automatic Construction by Contour Crafting Technology

Contour Crafting is a novel technology in construction industry based on 3D printing that uses robotics to construct free form building structures by repeatedly laying down layers of material such as concrete. It is actually an approach to scale up automatic fabrication from building small industrial parts to constructing buildings. However, there are little information about contour crafting (CC) in current use; present paper aims to describe the operational steps of creating a whole building by the machine reviewing relevant literature. Furthermore, it will represent the advantages of CC usage compared to traditional construction methods, as well as its applicability in construction industry.

비정형 파라메트릭 건축부재형성 및 BIM 데이터 변환 프로세스 모델에 관한 연구

국내 AEC 산업 분야에 2000 년대 중반부터 그 적극적인 도입이 시작된 BIM 기술은 최첨단 건축, 초대형 건축, 비정형 건축 등을 중심으로 그 도입이 가속화 되어 왔다. 건물 구축 기술의 부족으로 의해 완공률이 낮았던 비정형 건축물들이 BIM 기술의 도입으로 많은 구축 성공 사례가 생기면서 건축가들이 비정형 건축 설계에 활발히 도전하고 있다. 그러나 비정형 설계가 가능한 모델러들은 설계, 시공, 유지관리 등에서의 데이터 관리가 효율적인 BIM 데이터의 구축이 어렵다. 그러므로 본 연구에서는 비정형 모델러에서 생성된 건축 부재 데이터의 BIM 데이터로의 변환 프로세스를 제안하였다. 제안된 프로세스 모델은 비정형 건축 부재를 형성하기 위한 형성 조건 수신부, 건축부재 생성부, 그리고 BIM 데이터 생성부 세가지 부분으로 구성된다. 구체적으로는 NURBS 기반 모델러에서 비정형 슬라브, 기둥, 보 파라메트릭 건축 부재 형성과 BIM 도구로의 데이터 전이 및 BIM 건축 부재 데이터 형성을 위한 프로세스 모델을 제안하며, 이를 실현하기 위한 프로토타입 시스템이 구현되었다. BIM technology has been used in the domestic AEC field since the middle 2000s. BIM has proved its worth in cutting-edge buildings, mega-buildings and freeform buildings in particular. Many freeform buildings could not be completed due to the low level of construction technique. However, many successful cases emerged after adopting digital technology, including BIM which encouraged architects to challenge freeform designs. The modeling software that can generate the freeform shape are not usually able to build the efficient BIM data type in the AEC industry. In this study a process model of the parametric freeform construction member generation and conversion to BIM data is shown and the prototype system is demonstrated.

LEGO® Friends: Leveraging Competitive Advantage

In December 2011 the Lego Group (TLG) announced the launch of Lego Friends, the company’s sixth attempt to market a product to girls. Lego Friends, which was supported by a $40 million global marketing campaign, was designed to introduce the fun of building with Lego bricks to girls, who represented less than 10 percent of Lego’s audience.The company’s poorly executed brand extensions and move from free-form building sets to story-driven kits had nearly cost it its independence in 2004, so the launch of Lego Friends was strategically important. However, within hours of the product’s appearance it was heavily criticized for reinforcing gender stereotypes and damaging the valuable Lego brand.Jørgen Vig Knudstorp, CEO since 2004, had saved TLG and ushered in an era of sales growth with a series of successful strategic initiatives. Would Lego Friends be another addition to TLG’s graveyard of failed products for girls, or would it prove popular and finally enable the company to double its sales and profits by reaching this segment?After analyzing the case, students should be able to: Understand the connection between a firm’s assets and its activities Identify new resources and capabilities required for a change in strategic focus Recognize the consequences of poorly matched assets and market opportunities

비정형 건축물의 외장 패널의 선제작과 시공을 위한 역설계 프로세스와 사례 분석을 통한 시사점 도출

3차원 이미지 스캐닝 기술은 복잡한 비정형 건축물의 외피의 정확한 형상과 위치 데이터를 확보하는데 효과적이다. 3차원 이미지 스캐닝 기술의 세부 과정인 점 군집화, 메쉬표면 분리, 넙스 표면 생성, 파라메트릭 솔리드 모델을 통하여 비정형 건축물의 형상을 구축할 수 있다. 이에 본 연구는 비정형 건축물의 외장재 제작과 시공을 위한 3차원 이미지 스캐닝에 의한 역설계 프로세스와 사례 분석을 통하여 시사점을 도출한다. 본 연구의 결과는 역설계 기술을 사용한 3차원 형상 기술과 설계 요소화 방법을 다양한 건설 프로젝트에 활용할 수 있을 것으로 판단된다. 3D laser scanning can be used for scanning the freeform surface and building a model from which the measurements could be taken, in order to solve the difficulty with getting access to the exact freeform shape and position data of the complex building envelope. The shape making process using 3D scanning is as follows: point cloud, mesh surface segmentation, NURBS(Non-Uniform Rational B-spline) surface generation, and parametric solid model generation. In this research, we review previous studies, reverse engineering notion, importance of reverse engineering usage for freeform envelope, and previous cases in order to identify the detail reverse engineering process for prefabrication and construction of freeform panels using 3D laser scanning technology. Therefore, the purpose of this research is to present a basic information which should be considered during design and construction phase and improve quality and constructibility of freeform building by analyzing the reverse engineering process and case study for prefabrication and construction of freeform panels using 3D laser scanning. The research results will enable 3D shape engineering and design parameterization using reverse engineering to be used in various construction projects.

Diagrid Systems for Structural Design of Complex-Shaped Tall Buildings

Today's architectural design trend based on the recognition of pluralism has led to multiple design directions for all building types including tall buildings. This contemporary design trend has produced many complex-shaped tall buildings, such as twisted, tilted, tapered and freeform towers. Among many different structural systems developed for tall buildings, the diagrid system, with its powerful structural rationale and distinguished aesthetic potential, is one of the most widely used systems for today's tall buildings. This paper studies structural performance of diagrid systems employed for complex-shaped tall buildings. Twisted, tilted, tapered and freeform tall buildings are designed with diagrid structures, and their structural performances are investigated. For the twisted diagrid study, the buildings are twisted up to 3 degrees per floor. In the tilted diagrid study, the angles of tilting range from 0 to 13 degrees. The impact of eccentricity is investigated for gravity as well as lateral loads in tilted towers. In the study of tapered diagrid structures, the angles of tapering range from 0 to 3 degrees. In the study of freeform diagrid structures, lateral stiffness of freeform diagrids is evaluated depending on the degree of fluctuation of free form. The freeform floor plans fluctuate from plus/minus 1.5 meter to plus/minus 4.5 meter boundaries of the original square floor plan. Parametric structural models are generated using appropriate computer programs and the models are exported to structural engineering software for design, analyses and comparative studies.

Integrated Design in Case of Digital Fabricated Buildings

The importance of the detailed BIM for buildings like the free-form building in our case cannot be emphasized enough in case of automated and especially additive manufacturing. Integral design of all building accessories like internal heating, ventilation, and air conditioning (HVAC), water supply, and drainage network installations is essential when applying additive manufacturing. In such a building it is impossible to build the ventilation network with traditional vertical and horizontal canals. Important benefit of digitally fabricated building can be internal topological optimization of building elements like walls and slabs for thermal insulation and structural capabilities. Application of large-scale additive manufacturing systems in the AECO industry is in early research phase. Future research directions are further parameterization of the interoperability demand function, BIM maturity, automation of workflow models, and new approaches for engineering of embedded building elements.

Shape optimization of free-form buildings based on solar radiation gain and space efficiency using a multi-objective genetic algorithm in the severe cold zones of China

In the severe cold zones of China, solar radiation is one of the most important issues in architectural design. The design seeks to make buildings receive more direct sunlight within the limits of the user’s comfort and simultaneously save energy and space. So far in China, the design of solar radiation has usually been qualitative, not quantitative, and it is often implemented by architects with experience or those following convention. This rough and rigid design approach is not accurate or efficient, particularly in the design of free-form buildings, which comprise a class of irregular-form buildings popular in current architectural design. Moreover, solar radiation is not the only thing that needs to be considered; shape coefficient and space efficiency should also be considered in free-form building design.This study proposes a method for a free-form building that receives more solar radiation though shape optimization and takes into account the other two objectives mentioned above.This paper provides a method with a “Modeling–Simulation–Optimization” framework. In the process of applying this method, parametric modeling with Rhinoceros and Grasshopper is used to build up the free-form building model, and the shape optimization of the building is processed by using the multi-objective genetic algorithm to make sure the three objectives—i.e., to maximize solar radiation gain, to maximize space efficiency, and to minimize the shape coefficient—are all achieved. Finally, a Pareto frontier is generated to show the optimal solutions and to assist designers in making final decisions.The case study shows that compared with the cube-shaped reference building, the total solar radiation gain of the optimized free-form shape building is 30–53% higher, and the shape coefficient value is reduced by 15–20%, with a decrease of less than 5% of the space-efficiency values.The proposed method, according to the basic process of architecture design, uses a performance-driven approach to find solutions that satisfy the requirements. It can be used in real architectural design to solve practical optimization problems.

Development of Process for Interoperability Improvement of BIM Data for Free-form Buildings Design using the IFC Standard

The introduction of BIM into complex buildings is essential and open BIM environment for communication between different kinds of work is an important element with the increasing demand for freeform buildings considering the value as being landmarks. IFC which is a standard integration model in the construction industry has been developed in buildingSMART International aiming for the interoperation of different information model tools. IFC is not only compatible for geometry information but also compatible for property information of the construction, and the standard protocol for data exchange in CAD tool representing BIM has been established for IFC. However, extensive time and costs have been spent since the geometry information is separately established and utilized in the certain software due to poor communication regarding precise geometry information in free-from projects of large scale. Information delivery has been insufficient because of not using BIM authoring tools but CAD-tools. The purpose of this study was to propose the process allowing the conversion of free-from shape into IFC file and the conversion with BIM software by coding the information regarding complex shape of free-from buildings. For this, the improvement in compatibility for geometry information and property information of free-form buildings is expected and improvement in communication and reduction in work duration and costs in different works in each area of the construction industry handling complex shape and property information are ultimately expected.

Building Structures Roofed with Multi-Segment Corrugated Hyperbolic Paraboloid Steel Shells

An innovative method of shaping free form buildings composed of many original complete parts roofed with profiled steel sheets transformed effectively into hyperbolic paraboloid strips is proposed in the paper. The method uses tetrahedral compositions of various kinds connected one to another with their relevant faces contained in planes of a spatial network called control structure. The control structures enable: a) controlling structural systems and architectural forms of the complex buildings as well as their morphological systems, b) arranging regularly the roof shells in three-dimensional space, c) integrating the roof and elevation forms as well as their consistent composition into the natural and built environments. The effectiveness of the transformations consists in the fact that displacements of adjacent folds in the sheeting are big, whereas strain is small. The effective transformations affect the fold's shape in such a way that the folds are contracted in the middle on their length and stretched at their crosswise ends depending on supporting conditions produced by curvature and a mutual location of skew directrices. The supporting conditions are diversified along each directrix, so the diversified arrangement of the supporting points of the shell folds to the skew directrices has to be calculated. For this purpose, an innovative computer program was created. Because of the diversified fold shape changes, two individual shell sheeting's cannot be connected one to another with their transversal borders to obtain a smooth shell. However, many shells can be set together with their transversal edges to achieve a compound ribbed roof of medium or large span. Thus, the resultant shell roof has to be characterized by edges disturbing its smoothness.

자유형상 보요소 해석을 위한 NURBS기반의 전·후처리 모듈 개발

Recently, the free form buildings are constructed frequently. Exterior and interior components of these buildings have the free cross-section and a curved shape. So, There are many usages of classical finite element having tapered section and free-style shape. Some general commercial applications like ETABS, SAP2000, MIDAS are usually used for the safety evaluation of the free form structures. However, there are some limits in the accuracy of structural analysis and the length of analysis time because a very complicated finite element mesh have to be used. Therefore, In this study, a pre and post program module was developed to take advantage of general 3-D curved beam element which has a free-style curved shape and mathematical backgrounds. Pre-post processing module has been developed in this study was developed to control the curvature of the curved members by the NURBS control points. As a result, fast geometric modeling than was possible commercial applications. In addition, realistic depiction of the shape and behavior patterns were possible because of the free-form building allows visual check of the free form.

Panelizing Algorithms for Free-Form Concrete Panels Considering Esthetic Surfaces

For free-form buildings to have a landmark image, their exterior design should be esthetic. Although the overall design of free-form buildings is significant, whether the shape, size, curvature and joint of members that compose the buildings make them esthetic or not should be taken into consideration. The free-form buildings designed are mostly panelized for the esthetic aspect of buildings and convenience of design works, so the models designed by architects should be newly panelized considering production. Thus, the purpose of this study is to develop Panelizing Algorithms for Free-form Concrete Panels considering Esthetic surfaces (design aspect). The developed algorithms panelize the buildings already designed, so as to verify the usefulness of algorithms. Further studies are required on panelizing members that can be produced by CNC machines and FCP panelizing algorithms using parametric designs.

Automated Costruction by Contour Crafting

Contour crafting (CC) is a advanced building printing technology being researched by Behrokh Khoshnevis of the University of Southern California's in the Viterbi School of Engineering that uses a computer-controlled crane to build homes rapidly and efficiently with substantially less manual labor. It was originally designed as a method to construct molds for industrial parts. Khoshnevis decided to adapt the technology for rapid home construction as a way to rebuild homes after natural disasters, like the devastating earthquakes. Using a quicksetting, concrete-like material, contour crafting forms the walls of houses layer by layer until floors and ceilings are set in place by the crane. This great concept calls for the insertion of structural components, air conditioning, plumbing, wiring, utilities, and even consumer devices like audiovisual systems as the layers are built. Automation has been very advanced technology in manufacturing sector but the growth of automation in construction sector has been quite slow. Conventional methods of manufacturing automation cannot construct the giant structures with all internal features. This is the reason behind the slow rate of growth in construction automation. Contour Crafting has a great potential in automated construction of whole structures as well as its sub-components. Using this process, a single house or a colony of houses, each with possibly different designs may be automatically constructed in a single run. This research paper also deals with the application of CC in building habitats on other planets. CC will most probably be one of the very few feasible approaches for building structures on other planets, such as Moon and Mars, which are being targeted for human colonization. Contour Crafting is an emerging technology that uses robotics to construct free form building structures. The research paper aimed at providing a systematic solution for improving the overall Contour Crafting system efficiency in custom-designed buildings. The paper also deals with some practical construction issues.

A Study on Freeform Optimization using BIM Technology

Freeform buildings are now designed and constructed globally because of digital design trend, advance construction technology, and landmark value. However, due to the lack of freeform building engineering and construction management experience, it has become a high risk project for construction companies. During construction stage; many design changes, fabrication defects and construction quality issues are being raise, which results project cost increase and schedule delays. This study proposes freeform optimization process to mitigate the risk from happening at construction stage. Using BIM, visualization, parametric model and automation functions, various design alternatives are made to apply curvature analysis, panelization, panelization evaluation, and panel optimization for most efficient solution.

Flexible Manufacturing of Double-Curved Sheet Metal Panels for the Realization of Self-Supporting Freeform Structures

Product development is complex due to the manifold requirements resulting from various perspectives, such as design, production, safety and sales. A concurrent engineering (CE) approach permits to respect all perspectives in the early development stage. However, in the architecture and construction sector for example, CE is particularly difficult to realize, because the central steering for this collaboration process is missing. Thus, the application of CE in the research sector can promote technical progress and cost reduction. In the specific field of freeform architecture, in most cases an individual shape of single components is unavoidable and the use of standard components impossible. Due to missing universal and mature construction concepts for freeform buildings, they are mostly realized with customized solutions often including material-consuming substructures, while the visible skin has only limited structural and functional properties.In this context the present paper proposes a novel universal panel system made of double-curved sheet metal layers enabling the assembly of self-supporting lightweight structures for the realization of freeform surfaces. The panel system has been developed in cooperation of architects, construction and production engineers, successfully applying an interdisciplinary CE approach. As a result, the concept allows for material and cost efficient solutions applicable for a wide range of freeform applications. The detailed development of the panel system is still in progress.Besides the general panel concept, the paper presents in particular the corresponding manufacturing chain and the tooling concept. Accounting for the varying part geometries in this application a flexible manufacturing chain based on the combination of stretch forming and incremental sheet forming has been developed. The entire production process is implemented in a single machine setup and successfully tested on a small-scale prototype.

Developing the preliminary cost estimate for the free-form building facade in conjunction with the panel optimization process

The exterior surfaces of the free form buildings contain the panels with very complex curvature. While the panels incarnate a symbolic and remarkable building facade in the urban environment, constructing the panels is extremely complex. Because the bigger the curvatures of the panels, the more expensive the construction cost, a free-form building designer needs to perform the process to mitigate the curvatures of the panels at the early design stage without damaging the features of the free-form façade in parallel with estimating the cost to construct the panels (i.e., panel optimization). However, at the upfront design phase, estimating cost of design alternatives and finding a good one that meets both design intention and budget limit is very difficult. Most designers lack understanding, technology, and data on panel optimization. This study suggests how to optimize the panels for free-form facade by using Grasshopper, a widely-used application that a building designer can easily approach as well as how to calculate the construction cost change in conjunction with the optimization process. The panel optimization is mainly carried out by connecting Grasshopper's continuity analysis function with curvature analysis function. A case study is performed on a recently completed free-form building project in Korea to verify the applicability of the study result.

Optimization of a free-form building shape to minimize external thermal load using genetic algorithm

This study aimed to propose an optimization process for a free-form building shape in terms of the thermal load characteristic in the early design stage. Geometric modeling of a model free-form building was performed using a parametric design method with Rhinoceros. The model free-form building's surface was divided into finite elements by generating a mesh using Grasshopper, which is an add-in program of Rhinoceros. Geometric information was extracted from each finite element and used to estimate the heat gain and loss characteristics of the whole free-form building. A free-form building shape optimization process was proposed based on the genetic algorithm (GA). Its applicability was demonstrated by deriving the optimized shape of the model free-form building for various climate zones. Established models that returned the thermal characteristics of a free-form building were used as objective functions, which are critical in the GA optimization process. The results showed that the proposed process could rapidly predict and optimize the variation of the heat gain and loss characteristics that was caused by changing the building shape.