Interactive Thin Elastic Materials

Despite great strides in past years are being made to generate motions of elastic 1 materials such as cloth and biological skin in virtual world, unfortunately, the computational cost of realistic high-resolution simulations currently precludes their use in interactive applications. Thin elastic materials such as cloth and biological skin often exhibit complex nonlinear elastic behaviors. However, modeling elastic nonlinearity can be computationally expensive and numerically unstable, imposing significant challenges for their use in interactive applications. This paper presents a novel simulation framework for simulating realistic material behaviours with interactive frame rate. Central to the framework is the use of a constraint-based multi-resolution solver for efficient and robust modelling of the material nonlinearity. We extend a strain limiting method to work on deformation gradients of triangulated surface models in three dimensional space with a novel data structure. The simulation framework utilises an iterative nonlinear Gauss-Seidel procedure and a multilevel hierarchy structure to achieve computational speed ups. As material non-linearity are generated by enforcing strain limiting constraints at a multilevel hierarchy, our simulation system can rapidly accelerate the convergence of the large constraint system with simultaneous enforcement of boundary conditions. The simplicity and efficiency of the framework makes simulations of highly realistic thin elastic materials substantially fast and is applicable of simulations for interactive applications

Post-buckling behaviour of prestressed steel stayed columns

Imperial Users onl

The Inuence of Cross-Section Shape of the Car Roof Rail on the Quqsi-Dynamic Buckling Modes

This paper presents the results of numerical analysis of the aluminium profiles subjected to dynamic, of different time duration impulse loading. The analysis includes the change in cross–section of the roof rail, ranging from the open ”C profile”, through closed ”Rectangular” to hybrid ”Tandem with brackets”. The main aim of this study is to model the dynamic response of the car roof rail to impulse loading, which may appear in case of collision

Cellular buckling in stiffened plates

An analytical model based on variational principles for a thin-walled stiffened plate subjected to axial compression is presented. A system of nonlinear differential and integral equations is derived and solved using numerical continuation. The results show that the system is susceptible to highly unstable local--global mode interaction after an initial instability is triggered. Moreover, snap-backs in the response showing sequential destabilization and restabilization, known as cellular buckling or snaking, arise. The analytical model is compared to static finite element models for joint conditions between the stiffener and the main plate that have significant rotational restraint. However, it is known from previous studies that the behaviour, where the same joint is insignificantly restrained rotationally, is captured better by an analytical approach than by standard finite element methods; the latter being unable to capture cellular buckling behaviour even though the phenomenon is clearly observed in laboratory experiments.Comment: 22 pages, 9 figures, 1 table, accepted for publication. Proceedings of the Royal Society A, 201

Stretchable electronics for artificial skin

Postprint (published version

Frontiers of Adaptive Design, Synthetic Biology and Growing Skins for Ephemeral Hybrid Structures

The history of membranes is one of adaptation, from the development in living organisms to man-made versions, with a great variety of uses in temporary design: clothing, building, packaging, etc. Being versatile and simple to integrate, membranes have a strong sustainability potential, through an essential use of material resources and multifunctional design, representing one of the purest cases where “design follows function.” The introduction of new engineered materials and techniques, combined with a growing interest for Nature-inspired technologies are progressively merging man-made artifacts and biological processes with a high potential for innovation. This chapter introduces, through a number of examples, the broad variety of hybrid membranes in the contest of experimental Design, Art and Architecture, categorized following two different stages of biology-inspired approach with the aim of identifying potential developments. Biomimicry, is founded on the adoption of practices from nature in architecture though imitation: solutions are observed on a morphological, structural or procedural level and copied to design everything from nanoscale materials to building technologies. Synthetic biology relies on hybrid procedures mixing natural and synthetic materials and processes