Search NASA⌕ Search

Engineering topics

Stricklin, J. A.

Publications and source records attributed to Stricklin, J. A..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Displacement incrementation in non-linear structural analysis by the self-correcting method

The prediction of nonlinear structural behavior by the finite element method wherein buckling does not occur has received considerable attention and, with it, reasonable success has been achieved. However, the post-buckling problem has been less actively pursued probably because of the inherent numerical difficulties encountered. This note reviews very briefly the numerical methods currently being used for pre- and post-buckling analysis and presents a self-correcting approach based on load and displacement incrementation which is shown to be efficient, reliable, and easy to program. Numerical solutions are presented which demonstrate the effectiveness of the method.

Haisler, W. E.↗
NASA NTRS1976

Symmetric stiffness matrix for incompressible hyperelastic materials

Symmetric structure matrices are derived for solving plane strain and axisymmetric problems involving incompressible hyperelastic materials. An infinite hollow cylinder subjected to internal pressure is considered as an example. Displacement and hydrostatic pressure profiles are calculated using the Newton-Raphson iteration technique. The results are in good agreement with the exact curves.

Takamatsu, T.↗
NASA NTRS1976

On the use of two hardening rules of plasticity in incremental and pseudo force analysis

The tangent stiffness and pseudo force forms of the equations of motion are first derived within the context of a total Lagrangian formulation. After a brief discussion of available incremental theory plasticity models, the small strain formulations and computational procedures of the mechanical sublayer model and combined kinematic-isotropic hardening as used in the general purpose structural analysis program AGGIE I are presented. Several sample problems are then presented along with recommended guidelines for use of the two plasticity models.

Hunsaker, B., Jr.↗
NASA NTRS1974

Large deflection elastic-plastic dynamic response of stiffened shells of revolution

This paper presents the formulation and check-out problems for a computer code DYNAPLAS, which analyzes the large deflection elastic-plastic dynamic response of stiffened shells of revolution. The formulation for spacial discretization is by the finite element method with finite differences being used for the evaluation of the pseudo forces due to material and geometric nonlinearities. Time integration is by the Houbolt method or central differences. The stiffeners may be due to concentrated or distributed eccentric rings and spring supports at arbitrary angles around the circumference of the elements. Check-out problems include the comparison of solutions from DYNAPLAS with experimental and other computer solutions for rings and conical and cylindrical shells. A hypothetical submarine including stiffeners and missile tube is studied under a combination of hydrostatic and dynamically applied asymmetrical pressure loadings.

Stricklin, J. A.↗
NASA NTRS1974

The static nonlinear analysis of shells of revolution (SNASOR II)

Utilizing stiffness matrices and supplying as input the loading and boundary conditions, program generates equilibrium equations for structure. Nonlinear strain energy terms result in pseudogeneralized forces which are combined with applied generalized forces. Resulting set of nonlinear algebraic equilibrium equations is solved by one of several methods.

Stricklin, J. A.↗
NASA NTRS1972

Large deflection elastic-plastic dynamic response of stiffened shells of revolution

The formulation and check out porblems for a computer code DYNAPLAS, which analyzes the large deflection elastic-plastic dynamic response of stiffened shells of revolution, are presented. The formulation for special discretization is by the finite element method with finite differences being used for the evaluation of the pseudo forces due to material and geometric nonlinearities. Time integration is by the Houbolt method. The stiffeners may be due to concentrated or distributed eccentric rings and spring supports at arbitrary angles around the circumference of the elements. Check out porblems include the comparison of solutions from DYNAPLAS with experimental and other computer solutions for rings, conical and cylindrical shells and a curved panel. A hypothetical submarine including stiffeners and missile tube is studied under a combination of hydrostatic and dynamically applied asymmetrical pressure loadings.

Stricklin, J. A.↗
NASA NTRS1972

Evaluation of solution procedures for material and/or geometrically nonlinear structural analysis by the direct stiffness method.

This paper presents an assessment of the solution procedures available for the analysis of inelastic and/or large deflection structural behavior. A literature survey is given which summarized the contribution of other researchers in the analysis of structural problems exhibiting material nonlinearities and combined geometric-material nonlinearities. Attention is focused at evaluating the available computation and solution techniques. Each of the solution techniques is developed from a common equation of equilibrium in terms of pseudo forces. The solution procedures are applied to circular plates and shells of revolution in an attempt to compare and evaluate each with respect to computational accuracy, economy, and efficiency. Based on the numerical studies, observations and comments are made with regard to the accuracy and economy of each solution technique.

Stricklin, J. A.↗
NASA NTRS1972

Static geometric and material nonlinear analysis.

This paper presents a survey of four aspects of nonlinear analysis - basic formulation, plasticity relations, computational procedures, and methods of solution. This survey is for the most part limited to static geometric and material nonlinear analysis under the assumption of small strains. The two formulations covered are the total Lagrangian and the incremental moving coordinate formulations. A comparison of the two formulations is presented and an attempt is made to clarify the underlying basis of each formulation. The survey of computational procedures reveals that most researchers are now using some form of numerical integration to evaluate nonlinear contributions.

Stricklin, J. A.↗
NASA NTRS1971

Self-correcting incremental approach in nonlinear structural mechanics.

A self-correcting, incremental-solution procedure has been developed which seems to be promising in solving geometrically highly nonlinear problems. The procedure is also applicable to systems with many degrees of freedom where the bandwidth of the stiffness matrix is large compared with the narrow bandwidth for the shell of revolution.

Massett, D. A.↗