Damage Simulation Tool For Composite Laminates
The simulation combines existing fracture mechanics based damage propagation techniques with a discrete approach to modeling discontinuities in finite elements. Additionally, the use of an advanced laminate theory recovers deformation and stress information that would normally require a high fidelity model. To accomplish this, the same theoretic and analytical concepts that a high fidelity numerical simulation tool utilizes for laminate damage simulation are placed in the context of a low fidelity finite element. In taking this approach, a laminate can be modeled as a single layer low fidelity shell mesh that has the ability to locally increase fidelity and represent a delamination based damage process but only if it is determined that one should occur. The numerical simulation tool's performance has been validated against numerical benchmarks as well as experimental data.
materials and coatings
Flexible Lightweight Radiation Shielding
The thin, lightweight radiation shielding is comprised of a low Z/high Z/low Z layered structure wherein the low Z layer is composed of titanium and the high Z layer is composed of either tantalum or antimony. Modelling of radiation shielding performance from a Cobalt 57 source shows a 10 times reduction in gamma radiation when using tantalum and a 25 times reduction when using antimony as compared with a single layer of lead. In addition, the Z-shielding is 25% lighter than a single lead layer with the same thickness (0.35-0.36 mm). The direct textile spraying innovation outlined by this invention enables the ability to shape this shielding into garments via the sewing of metal coated fibers. The refractory metal shielding can be added onto a variety of commodity-based fabrics including glass fabrics.