PushMePullMe 3D is an interactive structural modeling application that has been developed to support the teaching of structural mechanics and design.
Design in practice is a multi-objective and iterative process, which involves several changes before converging to a solution accepted by all parties involved (architects, engineers, contractors, and clients). Although there are many sophisticated tools for accurate structural analysis, most of these are not suitable to be adopted for early-stage design because they require time-consuming setup and computation to carry out simulations. A lack of adequate assessment tools at early-stage design often results in expensive post-rationalization. In early-stage design, there is a need for an intuitive yet analytically informed approach to produce many what-if scenarios. This way, analysis feedback can be used as a generative means.
To meet this challenge, this research has developed a new formulation that combines computational techniques from computer graphics and established numerical methods for structural analysis This formulation is a vector-form finite element method that combines the Dynamic Relaxation (DR) method with the Co-Rotational formulation. Owing to the vector-form (i.e. no global stiffness matrix) rigid body motion and mechanisms can be simulated and structures can undergo arbitrarily large displacements (i.e. non-linear geometric behavior). Configurations that can be simulated with this method include reticular structures (e.g. cable nets, trusses, frames, tensegrity, and deployable) but also shells and solids. Benchmarks against analytical solutions and established commercial software have shown good accordance. Since convergence to equilibrium is iterative, both element and global buckling are considered and complex tasks such as shape optimization and form-finding can be carried out interactively.
PushMePullMe 3D enables structural forms to be manipulated to help build an understanding of how different types of structures respond under loading. The user can interact with structural models by pushing and pulling with the mouse or through a touch interface, while qualitative outcomes (such as stress and deformations) are visualized in real-time. The application has an intuitive interface that enables utilization by those with no prior knowledge of structural engineering. PushMePullMe 3D has been adopted by several educators worldwide.
Video demonstrations: https://vimeo.com/groups/pushmepullme
This work has been generously funded by the Engineering and Physical Sciences Research Council (EPSRC), Institution of Civil Engineers (ICE) and Expedition Engineering.
Research and Development Lead:
Contributions from Daniel Piker to the physics engine development and from Dr. Chris Williams to the mathematical model formulation are gratefully acknowledged.