Rigid Plastic Dynamics
The problem of rigid-plastic framed structures subjected to load pulses of arbitrary form, and of intensity such that substantial plastic deformation takes place, is treated by approximate means. The investigation is restricted to the range of low intensity excitation which induces a global dynamic response.
Mesh and nodal descriptions of the kinetic and kinematic laws are given for a structure with discrete masses under the restriction of small displacements, while the structural material is assumed rigid, perfectly plastic and strain-rate insensitive.
The vectorial relations of the finite element representation of the structure are integrated numerically by means of Newmark’s method. For each increment of time, there emerges a linear complementarity problem (LCP) which can be solved by a variant of Wolfe’s algorithm.
It proves essential to incorporate a numerical procedure which can identify and properly account for the unstressing that may occur within any particular increment of time. Such unstressing is undoubtedly a major feature of rigid-plastic dynamics.
KeywordsPlastic Hinge Linear Complementarity Problem Critical Section Discrete Mass Plasticity Relation
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- 2.Symonds, P. S., Survey of methods of analysis for plastic deformation of structures under dynamic loading, Brown University Report BU/NSRDC/1–67, 1967.Google Scholar
- 3.Jones, N., Response of structures to dynamic loading, Inst. Phys. Conf. Ser., No. 47 Chapter 3 (1979) 254–276.Google Scholar
- 4.Kaliszky, S., Dynamic plastic response of structures, In: Plasticity Today: Modelling, Methods and Applications, (Eds. A. Sawczuk and G. Bianchi) Elsevier Applied Science Publishers, London 1986, 787–820.Google Scholar
- 7.Lloyd Smith, D., Plastic limit analysis and synthesis of structures by linear programming, PhD Thesis, University of London 1974.Google Scholar
- 8.Al-Samara, M. A., Elastoplastic dynamics of skeletal structures by mathematical programming, PhD Thesis, University of London 1986.Google Scholar
- 9.Hodge, P. G., Jr., Plastic Analysis of Structures, McGraw-Hill 1959.Google Scholar