TitleLoading and structural response models for transverse deflection of circular plates subjected to near field explosions
NameBorenstein, Elan (author), Benaroya, Haym (chair), Baruh, Haim (internal member), Dill, Ellis H (internal member), Najm, Husam (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectMechanical and Aerospace Engineering,
DescriptionThis dissertation develops loading and structural response models to estimate the elastic deformation of a circular plate due to near field explosions. The loading model generates the nonuniform loading characteristic of a near field explosion on a circular plate. This loading model is unique as it uses the TNT equivalence factors for pressure and impulse separately when deriving the pressure profile. Most loading models either average the two factors together or use only one of them. An analytical model and two finite element models were developed to capture the response of the circular plate due to this nonuniform loading. The analytical model utilizes the von Kármán thin plate equations with a new assumed deformation profile developed in this dissertation. The typical deformation profile for a circular plate uses two constants to satisfy the boundary conditions. By adding torsional springs to the boundary of the plate and equating the springs' moment to the plate's internal moment, as well as carrying through with the von Kármán model, a new assumed profile is derived which has one parameter representing the boundary. This allows for a sensitivity analysis to be performed on the boundary condition parameter. In addition, this parameter has physical meaning, as it represents the stiffness of the torsional springs. The two finite element models were created using ANSYS Workbench. One is a simplified model with a constant thickness, circular plate geometry while the other has the actual geometry of the plate used in the experiments. The finite element models were created in a way to allow for the spatial and time dependent pressure loadings to be applied to the proper surface. Four experimental deformation data sets were provided by the U.S. Department of Homeland Security via the Transportation Security Laboratory. Each data set was compared to the analytical model and the two finite element models. The plate center deflection for the three structural models was found to be in good agreement with the experimental data. The results show that the loading becomes less accurate at very small scaled distances. Using the analytical model, the sensitivity of the maximum plate center deflection to parameter changes was estimated. The maximum deflection was found to be most sensitive to plate thickness. In addition, the sensitivity of maximum deflection to parameter uncertainties was calculated for the loading parameters. Depending upon the loading configuration, the greatest sensitivity to maximum deflection was found to depend on the uncertainty of a different parameter. This can be attributed to the highly nonlinear nature of this model.
NoteIncludes bibliographical references
Noteby Elan Borenstein
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.