Response of thin circular plates to central blast loading

• Main Author: Bimha, Richard Ernest
• Other Authors: Nurick, Gerald N
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2014
• Subjects: Mechanical Engineering
• Online Access: http://hdl.handle.net/11427/8488

Includes bibliographical references. === The large ductile deformation response and rupture of thin circular metal plates subjected to central blast loading is investigated using the ABAQUS general purpose finite element code. The finite element code incorporates non-linear geometry and material effects as well as strain rate sensitivity. A material failure model is also incorporated. The SA.XI axisymmetric sheet elements are used to model the plate. The shell element uses a theory that includes shear deformation effects but degenerates to the Kirchoff classical thin shell theory for thin shell elements. An explicit time integration scheme is considered more suitable than an implicit scheme for the analysis. A uniform mesh with 1000 elements is used in modelling the experiments. The mesh size is chosen to satisfy the conditions for numerical stability in the explicit analysis scheme. Two boundary conditions are considered; a plate clamped to its supports by bolts and a plate fully built-in. The pressure loading from the explosive charge is assumed to be uniform over the loaded area and decaying exponentially to the plate boundary. The pressure pulse is assumed to be rectangular. Material parameters are obtained from uniaxial quasi-static material tensile test results. The predicted plate responses; mid-plate permanent deflections, permanent deformation shape, strain rate dependence, strain predictions, response time and rupture are compared to experimental data and/or analytical and other numerical solutions. The predicted responses compare reasonably well with measured experimental results and/or with reported analytical and other numerical predictions.