Blast Mitigation Studies for All Metal Plate and Honeycomb Sandwich Panels
Open Access
- Author:
- Singh, Anand Kumar
- Graduate Program:
- Mechanical Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Ashok D Belegundu, Thesis Advisor/Co-Advisor
Ashok D Belegundu, Thesis Advisor/Co-Advisor - Keywords:
- Blast
design
optimization
plate
shape
honeycomb sandwich
validation - Abstract:
- This thesis investigates the optimization of a solid all-metal plate and a honeycomb sandwich panel to mitigate the effect of air blast loading, which consists of a short duration pressure pulse. With respect to the all-metal aluminum plate, the focus is on studying convergence of shape with regard to increasing number of velocity fields, well-posedness of the problem and effects of the different boundary conditions and off-center charge locations. The plates are modeled using LS-DYNA with 3-D hexahedral elements. The goal is to minimize the peak dynamic displacement of the back-face while monitoring plastic strain values, mass, and envelope constraints. Robust convergence of the numerical procedure is shown, as also the well-posedness of the problem formulation. A study with different boundary conditions along the edge has also been performed. The change in the optimized shape of the plate as the charge migrates away from the center is also studied. With respect to the honeycomb sandwich panel, the focus is to validate the homogenized stress-strain curve obtained via virtual testing of the unit cell. To this end, a large scale virtual crush test is performed on a detailed finite element model of the honeycomb to obtain a stress-strain curve. This curve shows good agreement with the parameterized curve used in homogenization. As the honeycomb core in sandwich panel flexes under the blast load, virtual three-point bending tests are also performed on the detailed finite element model of the sandwich panel. Deflection response, stiffness values and energy captured by the sandwich are then compared with corresponding values for the homogenized model.