Visualization of dynamic multibody simulation : with special reference to contacts

Sammanfattning: This thesis describes the requirements for creating a complete multibody visualization system. The complete visualization process includes everything from data storage to image rendering, and what is needed for a meaningful user-to-data interaction. Other topics covered in this thesis are 2D data packing for parallel simulation and remote simulation control.System modeling is an important aspect in multibody simulation and visualization. An object oriented approach is used for the multibody model, its basic simulation data structures, and for the visualization system. This gives well structured models and supports both efficient computation and visualization without additional transformations.The large amount of data and time steps require data compression. An compression algorithm specially designed for numerical data of varying step size is used for all time-varying data. All data is organized in blocks which allows fast selective data access during animation. The demands on a multibody simulation tool focusing on contact analysis represents a special challenge in the field of scientific visualization. This is especially true for multidimensional time-varying data, i.e. two dimensional surface related data.A surface data structure is presented which is designed for efficient data storage, contact calculation, and visualization. Its properties include an oriented multibody modeling approach, memory allocation on demand, fast data access, effective data compression, and support for interactive visualization.Contact stresses between two surfaces penetrate the material underneath the surface. These stresses need to be stored during simulation and visualized during animation. We classify this stresses as sub-surface stresses, thus a thin layer volume underneath the surface. A sub-surface data structure has been created. It has all the good properties of the surface data structure and additional capabilities for visualization of volumes.In many application fields the simulation process is computation intensive and fast remotely located computers, e.g. parallel computers or workstation clusters, are needed to obtain results in reasonable time. An application is presented which addresses all the major problems related to the data transfers over networks, unified access to different remote systems and administration across different organizational domains.