September 1, 2009
'FEAsy' analyzes designs from raw sketches to speed parts creationWEST LAFAYETTE, Ind. - Going back to the drawing board is much easier now that researchers have developed a new type of design program called FEAsy.
The program allows the designer to sketch a rough concept of the part and then analyze the part's characteristics while it is still only a drawing, said Karthik Ramani, a professor of mechanical engineering at Purdue University.
The concept represents a departure from conventional design methods, in which engineers use a painstaking procedure called finite-element analysis to test designs, he said.
"Ordinarily, the designer creates the component and then it has to go to other engineers who use specialized analysis software to test the design," Ramani said. "So the analysis gets done after many parts and systems are already designed, and it's too late to make major improvements or change design concepts at this stage."
The new approach represents a shortcut from the rough sketch to analysis.
"The idea is to bring analysis into the sketching stage of the design process," Ramani said.
Doctoral student Sundar Murugappan calls the new design program FEAsy, for finite element analysis made easy.
Findings were detailed in a paper presented Tuesday (Sept. 1) during the American Society of Mechanical Engineers Design Engineering Technical Conference in San Diego. The researchers received a 2009 Prakash Krishnaswami CAPPD Best Paper Award from the society.
"This is the first research paper that shows the feasibility of the program," Murugappan said.
One major challenge is endowing the software code with the ability to distinguish the difference between lines, circles and arcs, as well as symbols such as arrows drawn by users to describe a part.
"Say I'm a design engineer working for an automotive company and I want to find out how much stress my conceptual part can withstand," Ramani said. "I want to know where to drill the holes, and what kind of materials to use. I might have hundreds of ideas on shapes and so on."
The program automatically carries out steps including "geometric constraint solving" and "primitive beautification" to clean up the rough sketch.
"The computer has to do what we call sketch understanding," Ramani said. "If I don't close a circle completely, the computer knows I mean to draw a circle and completes it. If I don't draw lines exactly horizontal or perpendicular, the program recognizes these flaws and corrects them."
FEAsy then displays a formal version of the sketch and several alternatives for the designer to choose from, and it also saves the original rough sketch.
"Unlike other drawing programs on the market, you don't have to use specific tools to draw circles and squares and lines," Ramani said. "You just draw, and the computer understands what you are doing."
FEAsy also is "domain independent," meaning it does not assume the part being drawn is for a specific end use, such as an electrical circuit or a bookshelf bracket.
The ongoing research is funded by the National Science Foundation through the NSF's Computer and Information Science and Engineering Directorate.
Writer: Emil Venere, 765-494-4709, email@example.com
Source: Karthik Ramani, 765-427-7945, firstname.lastname@example.org
Purdue News Service: (765) 494-2096; email@example.com
Note to Journalists: An electronic copy of the research paper is available from Emil Venere, 765-494-4709, firstname.lastname@example.org. Demonstration videos are available on YouTube at is available at http://www.youtube.com/watch?v=sbKOrFF2EzU and http://www.youtube.com/watch?v=Y6_n326igw4
FEAsy: A Sketch-Based Interface Integrating Structural Analysis in Early Design
Sundar Murugappan, School of Mechanical Engineering
Karthik Ramani*, School of Mechanical Engineering, Purdue University
* Professor and author of correspondence, Phone: (765) 427-7945, Email: email@example.com
The potential advantages of freehand sketches have been widely recognized and exploited in many fields especially in engineering design and analysis. This is mainly because the freehand sketches are an efficient and natural way for users to visually communicate ideas. However, due to a lack of fundamental techniques for understanding them, sketch-based interfaces have not yet evolved as the preferred computing platform over traditional menu-based tools. In this paper, we address the specific challenge of transforming informal and ambiguous freehand inputs to more formalized and structured representations. We present a domain- independent, multi-stroke, multi-primitive beautification method that detects and uses the spatial relationships implied in the sketches. Spatial relationships are represented as geometric constraints and satisfied by a geometric constraint solver. To demonstrate the utility of this technique and also to build a natural working environment for structural analysis in early design, we have developed FEAsy (acronym for Finite Element Analysis made easy) as shown in Fig. 1. This tool allows the users to transform, simulate and analyze their finite element models quickly and easily through freehand sketching, just as they would draw on paper. Further, we have also developed simple, domain specific rules-based algorithms for recognizing the commonly used symbols and for understanding the different contexts in finite element modeling. Finally, we illustrate the proposed approach with a few examples.
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