Use Of ADINA Research Articles

Rotordynamic Analysis for a Turbo‐Machine with Fluid‐Solid Interaction and Rotation Effects

The rotordynamics and fluid dynamics of a turbo‐machine considering the effect of fluid‐solid interaction (FSI) are numerically investigated using finite element software ADINA. The iterative method is adopted in computation of coupled fields of displacement and fluid. What distinguishes the present study from previous ones is the use of ADINA′s rotational meshes and the FSI interface that separates the rotor surface from its surrounding fluid. The rotor′s center orbit and frequency response as well as the transient fluid dynamics are obtained with various axial flow speeds. By including real rotating motion of the rotor, this paper presents a better way to solve complicated rotordynamic problems of turbo‐machines that are operated in FSI circumstances.

Some experiences in the use of ADINA in the Swedish Nuclear Industry

This paper presents a number of engineering analysis problems solved from 1990 to 1996 where ADINA was used in the analysis. The problems are in the following areas: natural frequencies, dynamic loading, fatigue, fracture mechanics and natural convection-driven fluid flow. For most of the problems, a comparison between calculations and measurements is also presented. Our experience is that good numerical results can be achieved for static linear problems even when the geometry is complex, but in dynamic analysis it can be difficult to establish models that accurately contain all frequencies, and, of course, in non-linear analysis, the representation of the non-linear material behaviour provides a limit to the modelling accuracy.

Effect of vertical contraction joints in concrete arch dams

The vertical joints between the blocks of concrete in arch dams allow for contraction as the concrete cools during construction. Linear analyses, which ignore the presence of these joints, indicate large horizontal tensile stresses near the joints particularly when seismic loading is included. The U.S. Bureau of Reclamation is studying the nonlinear behavior of these vertical joints by making comparisons between parallel linear and nonlinear analyses of East Canyon Dam. This paper reports on the use of ADINA's gap element to model the contraction joints. The nonlinear analysis shows decreased values of the horizontal tensile stress at the expense of larger compressive stresses and increasing values of vertical tensile stress.

Improving the traffic safety on bavarian highway through profiled marking with use of ADINA

To improve the traffic safety a profiled marking system is used on Bavarian highway. With the help of program ADINA the magnification factor and the comfort index of the vehicle as well as the optimal gaps and thicknesses of the profiles are studied. The experimental measurement is also demonstrated.

Use of ADINA to model large deformation of the earth's lithosphere

This paper develops a Lagrangian displacement-based approach to the large-scale deformation of the lithosphere, the earth's outermost rheological layer. The lithosphere is characterized by rapid vertical variation of mechanical properties and deformation mechanism. The latter is thought to range from strongly temperature-dependent dislocation creep at a depth of about 100 km, to elasto-plasticity at the surface. The discussion summarizes the use of the Updated Lagrangian Henky technique, available in ADINA 5, to model finite strain in a rheologically complex continuum resembling the lithosphere. Non-linear finite element models of lithospheric deformation are compared to analytic results based on linearized equations.

The use of adina to predict system response to shock loadings: the hm motor protector. A case study

The paper describes the use of the ADINA finite element program applied in conjunction with the PATRAN-II software system in the formulation and solution of linear and nonlinear dynamic response. Emphasis is placed on the solution of a practical engineering problem. With ADINA and PATRAN II, detailed descriptions of the effects of shock loadings on major components of manufactured motor protectors were achieved.

Nonlinear finite element analysis of ship and offshore structures

The use of ADINA in some complex applications related to ship and offshore structures is presented. The intent of the paper is to survey these applications and indicate how nonlinear analysis can be an important ingredient in the study and design of such structures.

Use of ADINA for design optimization of nonlinear structures

This paper describes procedures for design sensitivity analysis and optimization of nonlinear structural systems with the computer program ADINA. Formulation of the structural optimization problem, design sensitivity analysis with nonlinear response using incremental finite element procedures, and two strategies to use ADINA for design optimization are described. A database and a modem database management system are used to couple ADINA with design sensitivity analysis and optimization modules. Comparison of optimum designs with linear and nonlinear structural responses for trusses with material and geometric nonlincarities are given. More complex structures can be optimized with the developed procedures to fully exploit the capabilities of ADINA.

Use of ADINA for nonlinear, three-dimensional analysis of intersecting tunnels in a rock medium

The degree of damage sustained by underground tunnels when the ground surface is subjected to overpressure caused by detonation of a nuclear device is assessed using the ADINA program. A system of two intersecting circular tunnels in a rock medium is modeled in three dimensions, with the rock assumed to be a Drucker-Prager material. Use of mesh generation tools Geo-mod and Supertab to prepare the complex model geometry is discussed, and experience with ADINA on the Cray computer for the large (1408-element, 5322-degree-of-freedom) model is described.

Use of ADINA in soil mechanics with case studies for excavations

The reliability and the variety of mathematical procedures related to incremental solution strategies for the nonlinear analysis as well as the general availability of the ADINA code make this latter particularly well adapted for soil and rock mechanics. These materials, especially the soils, have indeed a marked nonlinear strain-stress behaviour. These qualities are somewhat counterbalanced by the relative lack of constitutive laws applicable to soil however. The first part of this paper deals with the general and practical use of ADINA in soil and rock mechanics. The second presents, as case study, an ADINA use for the evaluation of the deformations around excavations in clayey soils. With the classical methods of geomechanics, it is not possible to determine these deformations correctly. Only the use of the FEM with nonlinear constitutive laws for ground performance and possibly considering also the pore pressure allows for the good evaluation of these deformations. Two very large excavations have been analysed in this way and it was possible to compare the results of the computation with many in situ observations.

The use of ADINA for analysis of mines with explosive fills

The structural response of a U.S. M-15 and a Soviet TM-46 land mine with explosive fills subjected to an externally applied pressure wave has been analyzed with the ADINA finite element code. The finite element model of the two-dimensional axisymmetric configurations predicted response out to 2 msec of real time. Failure of the mine case was predicted, based on a comparison of the value of the three-dimensional second invariant of plastic strain with that of the one-dimensional value obtained from tensile tests.