Mechanical System Design/Analysis Tool (MSAT) is a user-friendly software system that facilitates and accelerates the processes of synthesizing and analyzing designs of mechanical systems. MSAT is particularly well suited for designing aircraft engines. MSAT can be used in the preliminary-design stage as well as in the detailed-design stage of a product-development process.

MSAT is a multicomponent, multidisciplinary program with a modular architecture that organizes design-analysis tasks around object-oriented representations of (1) components of the engine or other system that one seeks to design, (2) analysis programs, and (3) data-transfer links among the constructs listed in (1) and (2). The modular architecture enables the rapid generation of input data streams for trade-off studies of various configurations of the system to be designed. Once the user has set up a sequence of computations, the data-transfer links automatically transport output from one analysis/design program for use as input in the next analysis/design program in the sequence. The computations are managed via constraint propagation - that is, by reference to constraints provided by the user as part of the design definition.

An Icon-Based Library-Browser subprogram in MSAT can be used in creating a mathematical model quickly and easily by performing pick-and-drop operations on the relevant icon(s). Here the icons represent components of an aircraft turbine engine.

MSAT provides a global perspective on system design. Building from subcomponents and components, the user sets detailed requirements for performances of components and of the system to be designed. The plug-and-play software framework of MSAT enables the user to add new analysis/design programs and/or components of the system to be designed and to perform trade-off studies rapidly; this capability helps to increase the quality of the ultimate design.

The plug-and-play feature of MSAT can also be utilized to make MSAT itself more versatile: New optimization and robust design software modules can be plugged in without extensive effort. As advanced computer programs are developed, the user can plug them in quickly, without having to delete older programs. This building-block application to the extension and improvement of MSAT is expected to reduce both the cost of further development of MSAT itself and cost of designing engineering systems by use of MSAT.

MSAT offers advantages of accuracy, efficiency, and speed. MSAT promotes accuracy by detecting errors in data entered by the user. A mathematical model of an engineering system can be built quickly and easily (see figure), and once the model has been built, the user does not have to rebuild the model for subsequent analysis. MSAT manages an optimization program and other analysis/design programs in performing multiple iterations without interaction with the user. In a typical case in which five iterations would be needed to arrive at a reasonable product design by conventional means, MSAT can perform the same analysis in one run, thereby saving about 80 percent in time and cost.

MSAT is expected to be integrated with NASA's Numerical Propulsion System Simulation (NPSS) computer program, which is used for coupling computer codes for the design and analysis of propulsion and propulsion/airframe systems.

MSAT has already been integrated with Monte Carlo, design-of-experiments, response-surfaces, and optimization software modules to provide a capability for robust preliminary design and uncertainty analysis. This capability can be exploited to determine whether a product is underdesigned (poses an excessive risk) or overdesigned (costs more than necessary).

This work was done by Charles Lawrence ofGlenn Research Center and HuaHua Lee, Mark Kolb, and Jack Madelone of General Electric Co.LEW-16710