Modeling And Simulation Of a Continious Folding Process Of An Origami Pattern

The engineering applications of origami has gathered tremendous attention in recent years. Various aspects of origami have different characteristics based on its application. The shape changing aspect is used in areas where size is a constraint. The structural rigidity aspect is utilized where strength is needed with a minimal increase in weight. When polymer or metal sheets are processed to have origami creases, they exhibit an improvement in mechanical properties. The sheets which create a specific local texture by means of tessellated folds patterns are called folded textured sheets[1]. These sheets are utilized to create fold cores. These light-weight sandwiched structures are heavily used in the aerospace industry, due to its ability to prevent moisture accumulation on the aeronautical structures at higher altitudes. The objective of the current research is to explore a new method for the continuous production of these folded textured sheets. The method uses a laser etching setup to mark the sheet with the origami pattern. The pattern is then formed by dies and passes through a conveyor system which is specifically arranged like a funnel to complete the final stage of the forming process. A simulation approach is utilized to evaluate the method. Results show the feasibility of the process along with its limitations. The design is made to be feasible for scaling up for large scale manufactur

EXTENDING ORIGAMI TECHNIQUE TO FOLD FORMING OF SHEET METAL PRODUCTS

This dissertation presents a scientific based approach for the analysis of folded sheet metal products. Such analysis initializes the examination in terms of topological exploration using set of graph modeling and traversal algorithms. The geometrical validity and optimization are followed by utilizing boundary representation and overlapping detection during a geometrical analysis stage, in this phase the optimization metrics are established to evaluate the unfolded sheet metal design in terms of its manufacturability and cost parameters, such as nesting efficiency, total welding cost, bend lines orientation, and maximum part extent, which aides in handling purposes. The proposed approach evaluates the design in terms of the stressed-based behavior to indicate initial stress performance by utilizing a structural matrix analysis while developing modification factors for the stiffness matrix to cope with the stress-based differences of the diverse flat pattern designs. The outcome from the stressed-based ranking study is mainly the axial stresses as exerted on each element of folded geometry; this knowledge leads to initial optimizing the flat pattern in terms of its stress-based behavior. Furthermore, the sheet folding can also find application in composites manufacturing. Thus, this dissertation optimizes fiber orientation based on the elasticity theory principles, and the best fiber alignment for a flat pattern is determined under certain stresses along with the peel shear on adhesively bonded edges. This study also explores the implementation of the fold forming process within the automotive production lines. This is done using a tool that adopts Quality Function Deployment (QFD) principle and Analytical Hierarchy Process (AHP) methodology to structure the reasoning logic for design decisions. Moreover, the proposed tool accumulates all the knowledge for specific production line and parts design inside an interactive knowledge base. Thus, the system is knowledge-based oriented and exhibits the ability to address design problems as changes occur to the product or the manufacturing process options. Additionally, this technique offers two knowledge bases; the first holds the production requirements and their correlations to essential process attributes, while the second contains available manufacturing processes options and their characteristics to satisfy the needs to fabricate Body in White (BiW) panels. Lastly, the dissertation showcases the developed tools and mathematics using several case studies to verify the developed system\u27s functionality and merits. The results demonstrate the feasibility of the developed methodology in designing sheet metal products via folding

Industrial product design by using two-dimensional material in the context of origamic structure and integrity

Thesis (Master)--Izmir Institute of Technology, Izmir, 2004Includes bibliographical references (leaves: 115)Text in English; Abstract: Turkish and English.xiii, 118 leavesThroughout the history of industrial product design, there have always been attempts to shape everyday objects from a single piece of semi-finished industrial materials such as plywood, sheet metal, plastic sheet and paper-based sheet. One of the ways to form these two-dimensional materials into three-dimensional products is bending following cutting. Similar concepts of this spatial transformation are encountered in the origami form, which has a planar surface in unfolded state, then transforms to a three-dimensional state by folding or by folding following cutting. If so, conceptually it may be useful to think of one-axis bending, which is a manufacturing technique, is somewhat similar to folding paper.In this regard, the studies in the scope of computational origami, which light the way for real-world problems such as how sheets of material will behave under stress, have applications especially in .manufacturing phase. of industrial product design.Besides manufacturing phase, origami design is also used as a product design tool either in .concept creating phase. (in the context of its concepts) or in 'form creating phase' (in the context of its design principles).In this thesis, the designing of industrial products, which are made from sheet material, is presented in a framework that considers the origami design. In the theoretical framework, evolutionary progression of origami design is discussed briefly in order to comprehend the situation of origami design in distinct application fields.Moreover, the elements, principles, basics of origami design and origamic structures are generally introduced. The theoretical framework is completed with the descriptions of the concepts on origami design and origamic structures. In the practical framework, typical applications that have origamic structures in distinct industrial product fields are exemplified. Furthermore, sheet materials and their bending process are taken up separately. By means of its excessive advantages, sheet metal bending is particularly emphasized. The practical framework is completed with several case studies base on sheet metal bending. Finally, the study is concluded with the evaluation of the origamic-structured product in respect of good design principles. Furthermore, designing by considering origami design is recommended to designer to design a good industrial product

Origami and Kirigami Design Principles for Optical Tracking, Energy Harvesting, and Other Applications

Origami and kirigami (the folding and cutting of paper, respectively, to achieve a desired shape) have been used in engineering to develop airbags, optical components, deployable spaceborne solar arrays, reprogrammable metamaterials, and load-bearing metal structures. Despite these efforts however, little has been shown beyond the packaging and load-bearing advantages of these three-dimensional approaches to structural design. This dissertation describes the use of dynamic, three-dimensional design principles to develop multifunctional mechanical and optoelectronic devices with improved performance, decreased fabrication costs, and greater economic value. First, we introduce a novel method of integrated, low-profile solar tracking whereby a simple kirigami pattern in thin-film gallium-arsenide solar cells enables tracking at the substrate level simply by stretching the sheet. The new tracker is inherently lightweight and very low profile; it is less susceptible to wind loading, which greatly reduces tracking system complexity, size, and cost, while also enabling new applications. System performance is considered as a function of cut geometry, materials selection, and geographic location, and optimized trackers are shown to generate up to 40% more energy per solar cell area over the course of a day relative to a stationary, flat panel module. Electrical and mechanical robustness are also considered with implications towards long-term solar tracking applications (i.e. >10,000 actuation cycles). Subsequently, we discuss a multifunctional system that combines kirigami solar tracking and integrated concentration optics to further reduce the overall cost of solar electricity. Optical design, mechanical response, and materials selection are considered to maximize optical and power concentration factor while also maintaining a simple design philosophy. The final system is shown to provide ~60x solar concentration, and further modifications will enable power concentration factors greater than 100x. Finally, similar design principles are extended to develop new applications including textured surfaces for flow manipulation and drag steering, kirigami patterns for tunable antennas, and origami tessellations for novel forms of electrochemical energy storage.PHDMaterials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/136941/1/allamour_1.pd

Origami Reconfigurable Electromagnetic Systems

With the ever-increasing demand for wireless communications, there is a great need for efficient designs of electromagnetic systems. Reconfigurable electromagnetic systems are very useful because such designs can provide multi-functionality and support different services. The geometrical topology of an electromagnetic element is very important as it determines the element’s RF performance characteristics. Origami geometries have significant advantages for launch-and-carry electromagnetic devices where devices need to fold in order to miniaturize their size during launch and unfold in order to operate after the platform has reached orbit. This dissertation demonstrates a practical process for designing reconfigurable electromagnetic devices using origami structures. Four different origami structures are studied and the integrated Mathematical-Computational-Electromagnetic models of origami antennas, origami reflectors and origami antenna arrays are developed and analyzed. These devices provide many unique capabilities compared with the traditional designs, such as band-switching, frequency tuning, polarization adjustment and mode reconfigurability. Prototypes are also manufactured to validate the performances of the designs. These designs change their geometry naturally, and they can be compactly packaged into small volume, which make them very suitable for spaceborne and satellite communication. Origami antennas and origami electromagnetics are expected to impact a variety of applications related to communications, surveillance and sensing

A Framework and Process Library for Human-Robot Collaboration in Creative Design and Fabrication

In the last two decades, the increasing affordability of industrial robots, along with the growing maturity of computational design software, has led architects to integrate robots into their design process. Robots have exceptional capabilities that enable the fabrication of geometrically complicated components and assembly of complex structures. However, the robot control and motion programming tools currently being adopted by designers were all initially intended for engineering-based manufacturing industries. When using computer-controlled tools, designers cannot adapt their designs to the production process in real time. Current industrial robot control systems force the designer to envision and embed all of the required machining data in the digital model before the fabrication process begins. This requirement makes the process of design to fabrication a unidirectional workflow. In pursuit of a solution, a growing body of research is exploring various human-robot collaboration methods for architectural practices. However, many of these studies are project- based, targeting the ad hoc needs of a particular robotic application or fabrication process. Consequently, this dissertation investigates a generalizable framework for human-robot collaboration that is rooted in the principles of distributed cognition. As an essential part of the research argument, the role of the tools of production in the formation of a designer's cognitive system is considered. This framework, defined for a bi-directional design and fabrication workflow, relies on and integrates material and fabrication feedback into the design process. The framework has three main components: interactive design, adaptive control, and a design and fabrication library. While different aspects of these components have been studied to various extents by other researchers, this dissertation is the first to define them in an integrated manner. Next, the requirements for each of these elements are introduced and discussed in detail. This dissertation focuses in more detail on the library component of the framework because compared to the first two components, it is the least investigated solution to date. A structure for the library is proposed so that the tacit knowledge of makers could be structured, captured, and reused. At its core, the library is a process-centric database where each process is supported by a set of tools, instructions, materials, and geometries required for the transformation of a part into its final form. Finally, this study demonstrates the generalizability of the library concept through a series of experiments developed for different material systems and with various robotic operations.Ph.D

STUDIES ON THE WRINKLING OF THIN POLYMER FILMS FLOATING ON LIQUID

This dissertation aims to broaden our understanding on wrinkling instabilities occurring on floating polymeric sheets, and tries to establish innovative methods that exploit these patterns in studies on material behavior and interfacial phenomena. We will address three major topics in this thesis including, i) characterization of the conditions required to buckle an annular disc, ii) characterization of wrinkles occurring around a droplet/bubble placed on a membrane that is kept taut at the liquid-air interface, and iii) using wrinkling patterns as a probe to understand the interfacial behavior and dynamics of ultrathin films. The first project in this thesis is about a thin floating elastic disc wrinkled by a droplet cast at the center. First, we obtain a three dimensional map of the deformed surface using confocal fluorescent microscopy. Then, we study the identical films in an inverted geometry where an air bubble is in contact with the film from its underside. In this configuration, a high-resolution optical profilometer facilitated the topographical analysis, which provided the detailed elasto-capillary measures of the problem. Finally, we study the patterns as a function of boundary conditions and material properties, where physical properties of the sheet, such as molecular confinement and physical aging, also change the size and wavelength of the pattern. The wrinkle patterns are also characterized in response to the change in surface tension of the bath liquid with the aid of a Langmuir Trough. This experimental set-up also facilitates the pattern formation on annular elastic discs, when variable peripheral forces create contraction within the film. Here, planar capillary forces dictate the controlled boundary conditions and probe a regime of deformation where the wrinkle length and the wavelength are empirically related. We should emphasize that the wrinkling of an annulus does not merely mimic the original droplet experiment, also leading to several remarkable discoveries. First, we observe that, in the studied thickness regime (e.g.the scaled extent and wavelength of wrinkles) observed for a range of thicknesses can be superimposed on another by displacing the data towards the hypothetical threshold required to wrinkle the zero-thickness sheet. We observe another thickness invariant phenomenon when the conditions of fold formation are found similar for films of identical annular aspect ratios. Finally, we study the time-dependent change in wrinkles forming on viscoelastic membranes. The dynamic behaviors of wrinkles are related to the rheological characteristics of polymer molecules of linear architecture confined into thicknesses comparable to their melt radius of gyration. In this study, we have found that the normalized size of wrinkles could be a measure of the stress and strain exerted by a droplet. We also have demonstrated that confinement significantly influences the dynamics of PS films. We close this chapter demonstrating that the wrinkling dynamics is related to the kinematics of the film under the droplet, and generally compares to the stress relaxation experiments performed on bulk samples

Tailoring stiffness of deployable origami structures

Origami has gained popularity in science and engineering because a compactly stowed system can be folded into a transformable 3D structure with increased functionality. Origami can also be reconfigured and programmed to change shape, function, and mechanical properties. In this thesis, we explore origami from structural and stiffness perspectives, and in particular we study how geometry affects origami behavior and characteristics. Understanding origami from a structural standpoint can allow for conceptualizing and designing feasible applications in all scales and disciplines of engineering. We improve, verify, and test a bar and hinge model that can analyze the elastic stiffness, and estimate deformed shapes of origami. The model simulates three distinct behaviors: stretching and shearing of thin sheet panels; bending of the flat panels; and bending along prescribed fold lines. We explore the influence of panel geometry on origami stiffness, and provide a study on fold line stiffness characteristics. The model formulation incorporates material characteristics and provides scalable, and isotopic behavior. It is useful for practical problems such as optimization and parametrization of geometric origami variations. We explore the stiffness of tubular origami structures based on the Miura-ori folding pattern. A unique orientation for zipper coupling of rigidly foldable origami tubes substantially increases stiffness in higher order modes and permits only one flexible motion through which the structure can deploy. Deployment is permitted by localized bending along folds lines, however other deformations are over-constrained and engage the origami sheets in tension and compression. Furthermore, we couple compatible origami tubes into a variety of cellular assemblages that can enhance mechanical characteristics and geometric versatility. Practical applications such as deployable slabs, roofs, and arches are also explored. Finally, we introduce origami tubes with polygonal cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. From a global viewpoint, the tubes do not need to be straight, and can be constructed to follow a non-linear curved line when deployed. From a local viewpoint, their cross-sections and kinematics can be reprogrammed by changing the direction of folding at some folds