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Thermal performance of automotive lighting must be considered early in the design phase of any lighting program. Several techniques are used to determine if a new design will pass thermal requirements. Many automotive lamps are design from experience, where historical information is used to qualify a design. Quantitative methods for determining lamp thermal performance allow optimization of parameters, which can affect lighting cost. This paper will present a comparison between experimental based modeling and computational fluid dynamics (CFD) approaches for determining the viability of an automotive lamp design.

Design Sensitivity Analysis (DSA) is applied to a thermal data base for automotive lamps. The DSA predicts temperatures on lamps with dimensions and light sources different from those in the data base. Predicted temperatures closely agree with the measured temperatures. These predictions are done early in the design phase and allow use of a Cardinal thermal data base than a Conventional one. The DSA can also be used in designing lamps for thermal safety.

Recent years have witnessed several important developments in: analysis of structures with finite element method for linear and nonlinear responses, design sensitivity analysis for linear and nonlinear responses, and optimization techniques in nonlinear programming. Exploitation of these developments in creating an integrated structural optimization system is warranted. Conducive environment for development of such a system is provided by high speed computers, CAD/CAM/CAE, efficient database management systems, parallel processing, automated design processes, etc. Such capabilities have created an environment to combine available general purpose finite element softwares and design optimization techniques into an integrated set. STROPT, the structural optimization system is a program evolved through usage of these potential features. The paper presents problem formulation, methods of design sensitivity analysis, program architecture, capabilities, and useful features of STROPT.

SECOPT, a program developed especially to help designers of automobile, bus body, aircraft and other structures where non-standard geometrical shapes of beam sections are encountered is discussed. The program integrates optimization of beam section with automatic calculations and satisfaction of constraints on section properties. Coordinates of the points (nodes) on a beam cross section that define its geometry are necessary for computation of section properties. Transformation of design variables into nodal coordinates without changing the geometry of the section is a key to the integration of the two components of the program. Need for introducing generic beam element of any prescribed shape in structural optimization programs and SECOPT's role in developing such a program are also discussed.