NEHRP Clearinghouse
- Title
- Dynamic Plastic Analysis Using Stress Resultant Finite Element Formulation.
- File
- PB275453.pdf
- Author(s)
- Lukkunaprasit, P.; Kelly, J. M.
- Source
- National Science Foundation, Washington, D.C., September 1977, 61 p.
- Identifying Number(s)
- UCB/EERC-77/21
- Abstract
- A stress resultant finite element formulation is developed for the dynamic plastic analysis of plates and shells of revolution undergoing moderate deformation. A nonlinear elastic-viscoplastic constitutive relation simulates the behavior of rate-sensitive and -insensitive materials. A local time step subdivision procedure is developed to stabilize the direct numerical integration of the system of nonlinear dynamic equations; satisfactory accuracy is obtained with large time steps. The simple nonlinear viscoplastic constitutive model approximates the nonlinear dynamic behavior of metals over a wide range of strain rates and has the advantage that the need to identify the state of the material during deformation is eliminated and the numerical algorithm thereby simplified. Direct step-by-step integration techniques are used to solve the system of equations governing the motion of a structure under dynamic loading. An implicit Runge-Kutta scheme in conjunction with a Newton-Raphson iteration technique is used in solving systems of first order ordinary differential equations.
- Keywords
- Nonlinear differential equations; Dynamic loads; Numerical integration; Clamped plates; Spherical shells; Earthquake engineering; Finite element analysis; Runge-Kutta method; Stress analysis; Metal plates; Plastic analysis; Plates; Dynamic structural analysis