A new approach to quantitative evaluation of a design for brazed structures

Brazement design is a critically important characteristic of a brazed joint structure. The design is responsible for reliability and proper service behavior of brazed products. According to the state of the art, a good design provides not only required properties of the brazed structure, but also a very high technological suitability. The latter is necessary in order to fabricate a product using the most economical manufacturing processes. Therefore, a rigorous approach to the assessment of the design beyond intuitive tools of the brazing art is necessary. However, many design variables should be considered during the development of a brazing task to reach the correct design solution. This variety of factors significantly complicates quantitatively assessing design. This paper offers such a rigorous methodology for achieving this goal. A system of quantitative characteristics inherent to a good design is proposed. Subsequently, a figure of merit called "design effectiveness" is defined to facilitate the related assessment procedure. This is accomplished by evaluating the final design solution in terms of design effectiveness. Subsequently, a comparison between multiple designs (the proposed vs. all the other options for similar brazed structures available in practice) should be performed. Almost 100 design criteria levels and corresponding weighing coefficients are included in the analysis and their impact is evaluated. Ultimately, the design figure of merit is defined. The result of such an analysis leads to a single value of the design effectiveness magnitude. This value ranges between 0 (worst design) and 1 (ideal design), with an actual value between 0 and 1 as a carrier of a very complex assessment effort. The application of this approach is illustrated by two examples extracted from the engineering practice. The design evaluations were made for a brazed aircraft structure and a computer hardware component.