Immersive 3D visualization laboratory concept
In the paper an advanced concept for a Virtual Reality (VR) CAVE installation is presented, which should allow for human immersion in a spatially unlimited virtual world. The CAVE will be completed by the end of 2013 in a special building designed and constructed for the purpose. The unit will simulate an autonomous movement of a human inside a computer generated scenery. The person immersed in VR space will be placed in a transparent sphere with a large diameter supported on rollers and equipped with a motion tracking system. Walking motion of the person will inflict the revolution of the ball and trigger changes in the computer generated images on screens surrounding the sphere thus creating an illusion of motion. The projection system will be equipped with a 3D simulation capability and supplemented with a spatial sound generation system.
Powered shoes
Powered Shoes is a locomotion interface using roller skates actuated by two motors with flexible shafts. The device is light-weighted and wearable. It enables the user to walk in virtual environment while his/her position is maintained. The user can walk in arbitrary direction in virtual environment.
Damage initiation and propagation in composite shells subjected to impact
Abstract The paper investigates the impact-induced damage initiation and propagation for laminated composite shells under low-velocity impact. A three-dimensional eight-node non-conforming element is described to analyze interlaminar stress distribution, and progressive failure. The damage analysis is performed by using Tsai–Wu quadratic failure criterion, Tsai’s damage modes and an additional delamination formula at all Gaussian points. The damage modes considered are matrix cracking, fiber breakage and delamination. The progressive failure is expressed by reducing stiffness of the material at all failed Gaussian points. Special attention is centered on curved laminates. Impact energy threshold for the onset of damage and transient damage size are predicted for composite shells. The analyses of the flat and curved laminates are compared for discussing their different damage mechanism. In addition, the influence of the stacking sequence, the thickness and the radius of curvature on damage behavior of composite shells are studied.