COMPUTER AIDED DESIGN SENSITIVITY OF LARGE SCALE SHIP STRUCTURE AND PREDICTION OF STATIC STRUCTURAL RESPONSE USING SENSITIVITY INFORMATION

In this paper, design sensitivity of large ship structures are computed based on the continuum approach. Once an FEM model of several thousand or more elements is analyzed by the established NASTRAN code, sensitivity of each design parameter of the element is computed by the continuum method and displayed by post- processor to indicate which parameters are more sensitive and which are not. Another use of sensitivity is the efficient re-analysis of responses, that is, new stress or displacement can be predicted using current sensitivity without FEM re-analysis. Sensitivity of stress of 2-D and 3-D ship structures is obtained and excessive initial stress on the transverse web is reduced below the yielding stress. In order to have an interactive procedure, a graphical user interface is developed using X-window and MOTIF. As a result of this sensitivity analysis, designers could analyze structural behaviour, predict new design performance, and synthesize efficiently in an interactive and visual environment.