Mesoscale Numerical Modelling and Failure Prediction of Automated Fibre Placement Composites

Automated fibre placement (AFP) is an advanced and fully automated composites manufacturing technique and offers a huge design space for lightweight composite structures through flexible fibre distribution and orientation. Advanced placed ply (AP-Ply) and variable stiffness laminate (VSL) are typical examples and are called Advanced AFP Laminates in this thesis. However, due to the machine tolerance and novel tow path manipulation, a great variety of intrinsic mesoscale geometric features (gaps, overlaps, tow drops, tow crimping, etc.) can be produced, which may have a great impact on the laminate strength depending on specific applications. Despite the increasing awareness of the significance of these features, understanding the corresponding effect on part performance is still challenging due to the huge parameter space, particularly for advanced AFP laminates. This research has developed a finite element (FE) method to predict the mechanical properties of AFP composites at coupon or part scale while retaining the intrinsic geometric features. The AP-Ply is an example used to validate this technique due to the sophisticated fibre architecture. Thus, several experimental programs including short beam shear, low-velocity impact, and compression-after-impact were conducted to facilitate understanding the effect of these geometric features on the structural performance of AP-Ply. The finite element method provided in this thesis was developed at mesoscale, specifically at a length scale of tows rather than plies or laminates in conventional methods. This method significantly improves the geometric fidelity of the model with the potential of depicting each tow and geometric feature individually. To improve the efficiency of model generation, an automated tow-wise modelling (TWM) algorithm was developed, aiming to build the part virtually following the robotic kinematics. The downstream use of TWM in the prediction of different failures is achieved with the implementation of a novel cohesive network approach, which greatly eases the pre-processing effort of explicitly allocating cohesive elements or developing complex fracture criteria. This method allows greater mesh size to be used in the crack front compared to conventional methods. The feasibility and accuracy of TWM in the prediction of mechanical properties of AFP composites were validated with AP-Ply experiments, specifically the short beam shear and low-velocity impact tests

Humanoid Robot Soccer Locomotion and Kick Dynamics: Open Loop Walking, Kicking and Morphing into Special Motions on the Nao Robot

Striker speed and accuracy in the RoboCup (SPL) international robot soccer league is becoming increasingly important as the level of play rises. Competition around the ball is now decided in a matter of seconds. Therefore, eliminating any wasted actions or motions is crucial when attempting to kick the ball. It is common to see a discontinuity between walking and kicking where a robot will return to an initial pose in preparation for the kick action. In this thesis we explore the removal of this behaviour by developing a transition gait that morphs the walk directly into the kick back swing pose. The solution presented here is targeted towards the use of the Aldebaran walk for the Nao robot. The solution we develop involves the design of a central pattern generator to allow for controlled steps with realtime accuracy, and a phase locked loop method to synchronise with the Aldebaran walk so that precise step length control can be activated when required. An open loop trajectory mapping approach is taken to the walk that is stabilized statically through the use of a phase varying joint holding torque technique. We also examine the basic princples of open loop walking, focussing on the commonly overlooked frontal plane motion. The act of kicking itself is explored both analytically and empirically, and solutions are provided that are versatile and powerful. Included as an appendix, the broader matter of striker behaviour (process of goal scoring) is reviewed and we present a velocity control algorithm that is very accurate and efficient in terms of speed of execution

AutoGraff: towards a computational understanding of graffiti writing and related art forms.

The aim of this thesis is to develop a system that generates letters and pictures with a style that is immediately recognizable as graffiti art or calligraphy. The proposed system can be used similarly to, and in tight integration with, conventional computer-aided geometric design tools and can be used to generate synthetic graffiti content for urban environments in games and in movies, and to guide robotic or fabrication systems that can materialise the output of the system with physical drawing media. The thesis is divided into two main parts. The first part describes a set of stroke primitives, building blocks that can be combined to generate different designs that resemble graffiti or calligraphy. These primitives mimic the process typically used to design graffiti letters and exploit well known principles of motor control to model the way in which an artist moves when incrementally tracing stylised letter forms. The second part demonstrates how these stroke primitives can be automatically recovered from input geometry defined in vector form, such as the digitised traces of writing made by a user, or the glyph outlines in a font. This procedure converts the input geometry into a seed that can be transformed into a variety of calligraphic and graffiti stylisations, which depend on parametric variations of the strokes

The Third Digital Turn of Non-Standard Architecture

This thesis explores Non-Standard Architecture, a movement in Postmodern architecture on non-Euclidean parametric and algorithmic formalism, and suggests a series of inherent limits prevented its full realisation. The thesis answers how these limits might be overcome by formulating the Third Digital Turn of Non-Standard. The Third Digital Turn emerged from the Second Digital Turn, an architectural movement from 2012 that realised parametric architecture through novel methods of form finding and construction using parametric data models and robotics. Through the Third Digital Turn the thesis formulates the Statutes of Non-Standard Architecture that describe the process of legislation in terms of the invention of new practice for Non-Standard Architecture. The thesis traces the evolution of the Second Digital Turn through novel interpretations of geometric lineage across architectural epochs, and identifies parametrisation with the codified law of architecture beginning in the Renaissance. The thesis identifies a gap between the possibilities of digital technologies in architecture and the current capacities of the building industry to realise them. Persistent challenges to achieving these objectives of automation are the limits of the regulatory environment and conservative construction practices. The thesis argues that such inherent limits can be overcome by reconsidering the existing regulations that frame technology and by implementing a methodology for ecological governance in architecture. The thesis contributes to the field in two key areas. First, it evolves Non-Standard architectural codification and production processes to extend the capacity of existing skills and technologies. Second, it indicates opportunities for environmental sustainability with protocols for Non-Standard design and construction, functional grading of material and automation in architecture

HyperCell: A Bio-inspired Design Framework for Real-time Interactive Architectures

This pioneering research focuses on Biomimetic Interactive Architecture using “Computationâ€, “Embodimentâ€, and “Biology†to generate an intimate embodied convergence to propose a novel rule-based design framework for creating organic architectures composed of swarm-based intelligent components. Furthermore, the research boldly claims that Interactive Architecture should emerge as the next truly Organic Architecture. As the world and society are dynamically changing, especially in this digital era, the research dares to challenge the Utilitas, Firmitas, and Venustas of the traditional architectural Weltanschauung, and rejects them by adopting the novel notion that architecture should be dynamic, fluid, and interactive. This project reflects a trajectory from the 1960’s with the advent of the avant-garde architectural design group, Archigram, and its numerous intriguing and pioneering visionary projects. Archigram’s non-standard, mobile, and interactive projects profoundly influenced a new generation of architects to explore the connection between technology and their architectural projects. This research continues this trend of exploring novel design thinking and the framework of Interactive Architecture by discovering the interrelationship amongst three major topics: “Computationâ€, “Embodimentâ€, and “Biologyâ€. The project aims to elucidate pioneering research combining these three topics in one discourse: “Bio-inspired digital architectural designâ€. These three major topics will be introduced in this Summary. “Computationâ€, is any type of calculation that includes both arithmetical and nonarithmetical steps and follows a well-defined model understood and described as, for example, an algorithm. But, in this research, refers to the use of data storage, parametric design application, and physical computing for developing informed architectural designs. “Form†has always been the most critical focus in architectural design, and this focus has also been a major driver behind the application computational design in Architecture. Nonetheless, this research will interpret the term “Form†in architecture as a continual “information processor†rather than the result of information processing. In other words, “Form†should not be perceived only as an expressive appearance based computational outcome but rather as a real-time process of information processing, akin to organic “Formationâ€. Architecture embodying kinetic ability for adjusting or changing its shape with the ability to process the surroundings and feedback in accordance with its free will with an inherent interactive intelligent movement of a living body. Additionally, it is also crucial to address the question of whether computational technologies are being properly harnessed, if they are only used for form-generating purposes in architecture design, or should this be replaced with real-time information communication and control systems to produce interactive architectures, with embodied computation abilities? “Embodiment†in the context of this research is embedded in Umberto Eco’s vision on Semiotics, theories underlying media studies in Marshall McLuhan’s “Body Extension†(McLuhan, 1964), the contemporary philosophical thought of “Body Without Organs†(Gilles Deleuze and Félix Guattari, 1983), the computational Logic of ‘Swarm Behavior’ and the philosophical notion of “Monadology†proposed by Gottfried Leibniz (Leibniz, 1714). Embodied computation and design are predominant today within the wearable computing and smart living domains, which combine Virtual and Real worlds. Technical progress and prowess in VR development also contribute to advancing 3D smart architectural design and display solutions. The proposed ‘Organic body-like architectural spaces’ emphasize upon the realization of a body-like interactive space. Developing Interactive Architecture will imply eliciting the collective intelligence prevalent in nature and the virtual world of Big Data. Interactive Architecture shall thus embody integrated Information exchange protocols and decision-making systems in order to possess organic body-like qualities. “Biologyâ€, in this research explores biomimetic principles intended to create purposedriven kinetic and organic architecture. This involves a detailed study/critique of organic architecture, generating organic shapes, performance optimization based digital fabrication techniques and kinetic systems. A holistic bio-inspired architecture embodies multiple performance criteria akin to natural systems, which integrate structural, infrastructure performances throughout the growth of an organic body. Such a natural morphogenesis process of architectural design explores what Janine M. Benyus described as “learning the natural processâ€. Profoundly influenced by the processes behind morphogenesis, the research further explores Evolutionary Development Biology (Evo-Devo) explaining how embryological regulation strongly affect the resulting formations. Evo-Devo in interactive architecture implies the development of architecture based on three fundamental principles: “Simple to Complexâ€, “Geometric Information Distributionâ€, and “On/Off Switch and Trigger.†The research seeks to create a relatively intelligent architectural body, and the tactile interactive spatial environment by applying the extracted knowledge from the study of the aforementioned principles of Evo-Devo in the following fashion: A. Extract a Self-Similar Componential Systembased approach from the “Simple to Complex†principle of Evo-Devo B. Extract the idea of “Collective Intelligence†from “Geometric information Distribution†principle of Evo-Devo C. Extract the principle of “Assembly Regulation†from “On/Off switch and trigger†principle of Evo-Devo The “HyperCell†research, through an elaborate investigation on the three aforementioned topics, develops a design framework for developing real-time adaptive spatial systems. HyperCell does this, by developing a system of transformable cubic elements which can self-organize, adapt and interact in real-time. These Hypercells shall comprise an organic space which can adjust itself in relation to our human bodies. The furniture system is literally reified and embodied to develop an intra-active space that proactively provokes human movement. The space thus acquires an emotive dimension and can become your pet, partner, or even friend, and might also involve multiple usabilities of the same space. The research and its progression were also had actively connected with a 5-year collaborative European Culture project: “MetaBodyâ€. The research thus involves exploration of Interactive Architecture from the following perspectives: architectural design, digital architectural history trajectory, computational technology, philosophical discourse related to the embodiment, media and digital culture, current VR and body-related technology, and Evolutionary Developmental Biology. “HyperCell†will encourage young architects to pursue interdisciplinary design initiatives via the fusion of computational design, embodiment, and biology for developing bio-inspired organic architectures

HyperCell: A Bio-inspired Design Framework for Real-time Interactive Architectures

This pioneering research focuses on Biomimetic Interactive Architecture using “Computation”, “Embodiment”, and “Biology” to generate an intimate embodied convergence to propose a novel rule-based design framework for creating organic architectures composed of swarm-based intelligent components. Furthermore, the research boldly claims that Interactive Architecture should emerge as the next truly Organic Architecture. As the world and society are dynamically changing, especially in this digital era, the research dares to challenge the Utilitas, Firmitas, and Venustas of the traditional architectural Weltanschauung, and rejects them by adopting the novel notion that architecture should be dynamic, fluid, and interactive. This project reflects a trajectory from the 1960’s with the advent of the avant-garde architectural design group, Archigram, and its numerous intriguing and pioneering visionary projects. Archigram’s non-standard, mobile, and interactive projects profoundly influenced a new generation of architects to explore the connection between technology and their architectural projects. This research continues this trend of exploring novel design thinking and the framework of Interactive Architecture by discovering the interrelationship amongst three major topics: “Computation”, “Embodiment”, and “Biology”. The project aims to elucidate pioneering research combining these three topics in one discourse: “Bio-inspired digital architectural design”. These three major topics will be introduced in this Summary.   “Computation”, is any type of calculation that includes both arithmetical and nonarithmetical steps and follows a well-defined model understood and described as, for example, an algorithm. But, in this research, refers to the use of data storage, parametric design application, and physical computing for developing informed architectural designs. “Form” has always been the most critical focus in architectural design, and this focus has also been a major driver behind the application computational design in Architecture. Nonetheless, this research will interpret the term “Form” in architecture as a continual “information processor” rather than the result of information processing. In other words, “Form” should not be perceived only as an expressive appearance based computational outcome but rather as a real-time process of information processing, akin to organic “Formation”. Architecture embodying kinetic ability for adjusting or changing its shape with the ability to process the surroundings and feedback in accordance with its free will with an inherent interactive intelligent movement of a living body. Additionally, it is also crucial to address the question of whether computational technologies are being properly harnessed, if they are only used for form-generating purposes in architecture design, or should this be replaced with real-time information communication and control systems to produce interactive architectures, with embodied computation abilities?   “Embodiment” in the context of this research is embedded in Umberto Eco’s vision on Semiotics, theories underlying media studies in Marshall McLuhan’s “Body Extension” (McLuhan, 1964), the contemporary philosophical thought of “Body Without Organs” (Gilles Deleuze and Félix Guattari, 1983), the computational Logic of ‘Swarm Behavior’ and the philosophical notion of “Monadology” proposed by Gottfried Leibniz (Leibniz, 1714). Embodied computation and design are predominant today within the wearable computing and smart living domains, which combine Virtual and Real worlds. Technical progress and prowess in VR development also contribute to advancing 3D smart architectural design and display solutions. The proposed ‘Organic body-like architectural spaces’ emphasize upon the realization of a body-like interactive space. Developing Interactive Architecture will imply eliciting the collective intelligence prevalent in nature and the virtual world of Big Data. Interactive Architecture shall thus embody integrated Information exchange protocols and decision-making systems in order to possess organic body-like qualities.   “Biology”, in this research explores biomimetic principles intended to create purposedriven kinetic and organic architecture. This involves a detailed study/critique of organic architecture, generating organic shapes, performance optimization based digital fabrication techniques and kinetic systems. A holistic bio-inspired architecture embodies multiple performance criteria akin to natural systems, which integrate structural, infrastructure performances throughout the growth of an organic body. Such a natural morphogenesis process of architectural design explores what Janine M. Benyus described as “learning the natural process”. Profoundly influenced by the processes behind morphogenesis, the research further explores Evolutionary Development Biology (Evo-Devo) explaining how embryological regulation strongly affect the resulting formations. Evo-Devo in interactive architecture implies the development of architecture based on three fundamental principles: “Simple to Complex”, “Geometric Information Distribution”, and “On/Off Switch and Trigger.” The research seeks to create a relatively intelligent architectural body, and the tactile interactive spatial environment by applying the extracted knowledge from the study of the aforementioned principles of Evo-Devo in the following fashion: A. Extract a Self-Similar Componential System based approach from the “Simple to Complex” principle of Evo-Devo B. Extract the idea of “Collective Intelligence” from “Geometric information Distribution” principle of Evo-Devo C. Extract the principle of “Assembly Regulation” from “On/Off switch and trigger” principle of Evo-Devo The “HyperCell” research, through an elaborate investigation on the three aforementioned topics, develops a design framework for developing real-time adaptive spatial systems. HyperCell does this, by developing a system of transformable cubic elements which can self-organize, adapt and interact in real-time. These Hypercells shall comprise an organic space which can adjust itself in relation to our human bodies. The furniture system is literally reified and embodied to develop an intra-active space that proactively provokes human movement. The space thus acquires an emotive dimension and can become your pet, partner, or even friend, and might also involve multiple usabilities of the same space. The research and its progression were also had actively connected with a 5-year collaborative European Culture project: “MetaBody”. The research thus involves exploration of Interactive Architecture from the following perspectives: architectural design, digital architectural history trajectory, computational technology, philosophical discourse related to the embodiment, media and digital culture, current VR and body-related technology, and Evolutionary Developmental Biology. “HyperCell” will encourage young architects to pursue interdisciplinary design initiatives via the fusion of computational design, embodiment, and biology for developing bio-inspired organic architectures

Physically Based Forehead Modelling and Animation including Wrinkles

There has been a vast amount of research on the production of realistic facial models and animations, which is one of the most challenging areas of computer graphics. Recently, there has been an increased interest in the use of physically based approaches for facial animation, whereby the effects of muscle contractions are propagated through facial soft-tissue models to automatically deform them in a more realistic and anatomically accurate manner. Presented in this thesis is a fully physically based approach for efficiently producing realistic-looking animations of facial movement, including animation of expressive wrinkles, focussing on the forehead. This is done by modelling more physics-based behaviour than current computer graphics approaches. The presented research has two major components. The first is a novel model creation process to automatically create animatable non-conforming hexahedral finite element (FE) simulation models of facial soft tissue from any surface mesh that contains hole-free volumes. The generated multi-layered voxel-based models are immediately ready for simulation, with skin layers and element material properties, muscle properties, and boundary conditions being automatically computed. The second major component is an advanced optimised GPU-based process to simulate and visualise these models over time using the total Lagrangian explicit dynamic (TLED) formulation of the FE method. An anatomical muscle contraction model computes active and transversely isotropic passive muscle stresses, while advanced boundary conditions enable the sliding effect between the superficial and deep soft-tissue layers to be simulated. Soft-tissue models and animations with varying complexity are presented, from a simple soft-tissue-block model with uniform layers of skin and muscle, to a complex forehead model. These demonstrate the flexibility of the animation approach to produce detailed animations of realistic gross- and fine-scale soft-tissue movement, including wrinkles, with different muscle structures and material parameters, for example, to animate different-aged skin. Owing to the detail and accuracy of the models and simulations, the animation approach could also be used for applications outside of computer graphics, such as surgical applications. Furthermore, the animation approach can be used to animate any multi-layered soft body (not just soft tissue)

Digital Alchemy: Matter and Metamorphosis in Contemporary Digital Animation and Interface Design

The recent proliferation of special effects in Hollywood film has ushered in an era of digital transformation. Among scholars, digital technology is hailed as a revolutionary moment in the history of communication and representation. Nevertheless, media scholars and cultural historians have difficulty finding a language adequate to theorizing digital artifacts because they are not just texts to be deciphered. Rather, digital media artifacts also invite critiques about the status of reality because they resurrect ancient problems of embodiment and transcendence.In contrast to scholarly approaches to digital technology, computer engineers, interface designers, and special effects producers have invented a robust set of terms and phrases to describe the practice of digital animation. In order to address this disconnect between producers of new media and scholars of new media, I argue that the process of digital animation borrows extensively from a set of preexisting terms describing materiality that were prominent for centuries prior to the scientific revolution. Specifically, digital animators and interface designers make use of the ancient science, art, and technological craft of alchemy. Both alchemy and digital animation share several fundamental elements: both boast the power of being able to transform one material, substance, or thing into a different material, substance, or thing. Both seek to transcend the body and materiality but in the process, find that this elusive goal (realism and gold) is forever receding onto the horizon.The introduction begins with a literature review of the field of digital media studies. It identifies a gap in the field concerning disparate arguments about new media technology. On the one hand, scholars argue that new technologies like cyberspace and digital technology enable radical new forms of engagement with media on individual, social, and economic levels. At the same time that media scholars assert that our current epoch is marked by a historical rupture, many other researchers claim that new media are increasingly characterized by ancient metaphysical problems like embodiment and transcendence. In subsequent chapters I investigate this disparity

SOLID-SHELL FINITE ELEMENT MODELS FOR EXPLICIT SIMULATIONS OF CRACK PROPAGATION IN THIN STRUCTURES

Crack propagation in thin shell structures due to cutting is conveniently simulated using explicit finite element approaches, in view of the high nonlinearity of the problem. Solidshell elements are usually preferred for the discretization in the presence of complex material behavior and degradation phenomena such as delamination, since they allow for a correct representation of the thickness geometry. However, in solid-shell elements the small thickness leads to a very high maximum eigenfrequency, which imply very small stable time-steps. A new selective mass scaling technique is proposed to increase the time-step size without affecting accuracy. New ”directional” cohesive interface elements are used in conjunction with selective mass scaling to account for the interaction with a sharp blade in cutting processes of thin ductile shells