GEM has expertise in several research areas of engineering importance.
Fire Damage Evaluation
Global Engineering and Materials, Inc. (GEM) has developed an Abaqus Fire Interface Simulator Toolkit (AFIST) for both composite and aluminum structures by packaging and integrating solution modules in fire simulation, thermal decomposition, non-linear viscoelastic damage state evolution, thermal-mechanical response prediction, and hybrid damage and failure prediction. A fully coupled fire-structure interaction module is implemented within GEM’s AFIST for fire response prediction of aluminum ship structures. A direct forcing immersed boundary method (IBM) is generalized and integrated with the current Fire Dynamics Simulator (FDS). With the developed fluid-structure coupling schedule, the AFIST is able to characterize a 3D complex geometry where its topology is not in conformation to a rectilinear FDS grid and capable of simulating moving complex geometries immersed in 3D fire flows. A thermal decomposition model is developed and implemented for AFIST for composite structures while a viscoplasticity material model is implemented in AFIST to capture the time-, stress-, and temperature-dependent constitutive behavior of aluminum structures.
Overview of AFIST application areas and key capabilities:
- Capable of coupled fire structure interaction simulation
- User-defined viscoplasticity model to characterize the time-, stress-, and temperature-dependent material response of aluminum alloys
- High speed FDS for large scale fire simulation
- Comprehensive material libraries for composite damage/decomposition prediction
- Simulation of fire dynamic of a moving boundary via an immersed boundary method
- Customized CAE using Abaqus’ model tree concept
- Automatic generation of input files for coupled fire and structure simulation
- Performance of heat and mass transfer coupling at multiple interfaces
- Display of coupling results via the Visualization Toolkit (VTK)
The AFIST toolkit has been applied for the fire response and thermal-mechanical damage prediction of both composite and metallic structures. As shown below, a simulation is performed for a full scale laminated plate subjected to a room fire using AFIST. Both the simulated mass flux and temperature distribution is shown below along with the display of the fire and structure interaction results viewed in ParaView. A slice view of room temperature and the thermal mechanical response of the laminated plate can be displayed together during the time evolution.
A two-way coupling in AFIST between Abaqus and FDS has been implemented and tested using an example of an arch beam in fire. The arch shaped metallic beam is placed above a pool fire in the center of a room. An image of the temperature result is shown in the figure. Due to the heat convection, the lower half of the center arch is heated up. The surface temperature of the beam and the temperature sliced at the x = 0 plane are presented in the figure.