Loading...
Please wait, while we are loading the content...
Similar Documents
On equivalence of discrete-discrete and continuum-discrete design sensitivity analysis
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Choi, Kyung K. Twu, Sung-Ling |
| Copyright Year | 1989 |
| Description | Developments in design sensitivity analysis (DSA) method have been made using two fundamentally different approaches as shown. In the first approach, a discretized structural finite element model is used to carry out DSA. There are three different methods in the discrete DSA approach: finite difference, semi-analytical, and analytical methods. The finite difference method is a popular one due to its simplicity, but a serious shortcoming of the method is the uncertainty in the choice of a perturbation step size of design variables. In the semi-analytical method, the derivatives of stiffness matrix is computed by finite differences, whereas in the analytical method, the derivatives are obtained analytically. For the shape design variable, computation of analytical derivative of stiffness matrix is quite costly. Because of this, the semi-analytical method is a popular choice in discrete shape DSA approach. However, recently, Barthelemy and Haftka presented that the semi-analytical method can have serious accuracy problems for shape design variables in structures modeled by beam, plate, truss, frame, and solid elements. They found that accuracy problems occur even for a simple cantilever beam. In the second approach, a continuum model of the structure is used to carry out DSA. |
| File Size | 845326 |
| Page Count | 20 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19890015810 |
| Archival Resource Key | ark:/13960/t53f9nq9m |
| Language | English |
| Publisher Date | 1989-04-01 |
| Access Restriction | Open |
| Subject Keyword | Structural Mechanics Finite Element Method Structural Design Finite Difference Theory Cantilever Beams Design Analysis Computer Aided Design Boundary Element Method Displacement Loads Forces Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
