# NASA Technical Reports Server (NTRS) 19760009731: Three-dimensional structural analysis using interactive graphics

The application of computer interactive graphics to three-dimensional structural analysis was described, with emphasis on the following aspects: (1) structural analysis, and (2) generation and checking of input data and examination of the large volume of output data (stresses, displacements, velocities, accelerations). Handling of three-dimensional

Author: NASA Technical Reports Server (NTRS)

Source: https://archive.org/

## Teaser

THREE-DIMENSIONAL STRUCTURAL ANALYSIS USING INTERACTIVE GRAPHICS- Johnny H.
Biffle and Hugh A.
Surnlin Sandia Laboratories INTRODUCTION The design process for a structure consists of three phases: (1) the conception, from which a design drawing is produced; (2) the analysis, from which the integrity of the structure is determined; and (3) the redesign, if it is deemed necessary.
When a three-dimensional analysis is needed, the time required to complete the analysis phase can be greatly reduced by the use of interactive graphics.
The first area which requires a large amount of time is describing the structure geometrically to the analysis computer program when given a design drawing.
When redesign is necessary, it becomes extremely important to be able to effectively redescribe the geometry of the structure for the analysis program.
The second time-consuming area is the inter^retation of the output from the analysis program. When using the finite element analysis technique, the structure is subdivided into a finite number of distorted brick type elements or blocks; this results in the generation of a large amount of data which must be checked. The use of interactive graphics is an effective means by which to generate and check input data and to correctly and completely examine the large volume of output data.
For a static analysis, the output data consist of the values of pertinent variables, such as stresses and displacements at each of the nodes (i.e., the corners of the elements) which are.
associated with the structure.
For a dynamic analysis, velocities and accelerations are also output and a set of data exists for several times during the dynamic process. If the structure is simple, without much curvature, batch processing is convenient and can be used effectively.
However, for a complex structure, interactive graphics is a valuable tool.
The analyst is provided the capability of not having to preselect the plots he wishes to see to examine the structure, as in...