Hi all,
I am a student learning Mechanical Design. I would like to use Topology Optimization early in my design process. My problem is mainly how to determine a design space when you start from nothing. Indeed, it is quite easier when you use Topology Optimization for re-designing a product: you can take the geometry of the past product (to be re-designed), removing some features and building an envelope of the past product which you can use as a design space. But when you “start from a blank page”, designing a totally new (innovative) mechanical component, the question I ask myself is how to estimate a good preliminary (rough) design space? I think maybe to find an answer to this question it is necessary to understand the “traditional” embodiment design phase (preliminary design phase) in the mechanical design process. That is why I am writing to you today hoping you will be able to give me some advices, references to book/publications, or maybe some lines of thought so I can further my studies.
I found the least practical learning materials with methodologies (or guidelines) about the preliminary design process at the assembly and part level (structures and mechanisms). I am particularly looking for methodologies (or guidelines) for configuration design and shape/form design.
By “configuration design” I think to:
* the synthesis of the architecture of the mechanical product (structure or mechanism),
* the arrangement of the individual components,
* the determination of interfaces (when to decide for an interface? where there will be interfaces? what they will look like? preliminary sizing of connections? etc…),
* the space allocation (volume, envelope, …) for each component and weight allocation also. Understanding how (System) Engineers/Architects allocate space for each mechanical part could help me a lot for determining a preliminary design space.
By “shape/form design”, I mean determining a rough preliminary geometry/topology (synthesis) of a mechanical part from the expected loads and all requirements (functional, interfaces, etc.). How was this done when we didn’t have topology optimization technique?
I think David G. Ullman in his book The Mechanical Design Process provides us with an interesting breakdown for “Form Generation” process (part of the embodiment design): “understanding Constraints and developing Configuration, Connections and components”.
I am looking since a long time for a case study which would present the design of a mechanical system from preliminary hand sketches to final design, showing all the iterations in details done on the digital mock-up from the first CAD models to final models. I think it would be very instructive to understand the mechanical design process.
I have also studied Systems Engineering a little, and I don’t really understand why it seems one stops the systems engineering process/engine at the sub-system level or for example at the component level. Can’t a mechanical component be seen as a system itself? Actually, what I am looking for are methodologies (or methods, processes, guidelines, etc…) for what could be called “mechanical(or mechatronical) (sub-)systems engineering”. For example, Functional analysis is widely taught in mechanical design courses here in France, but there is a big gap between functional analysis, functional architecture and mechanical architecture. For now, it seems nobody has been able to write methodologies (or guidelines) which would address that issue (is that even possible…?).
I lack insight and hindsight on these subjects but I hope my questions are still comprehensible.
Here is a short list of the learning materials I own on the subject:
* The Mechanical Design Process (Book) by David G. Ullman. Interesting but the chapter “Form Generation” is too succinct (it’s a pity because I think it is one of the rare texts dealing with the subject).
* About systematic design, the famous Engineering Design, A Systematic Approach (Book) by Pahl&Beitz. Very interesting also, deals a little with preliminary design (steps briefly described, some rules, principles and guidelines) but there is not in my opinion a detailed procedure/methodology for preliminary design phase.
* Mechanical Design of Machine Elements and Machines: A Failure Prevention Perspective (Book) by Jack A. Collins. It has a chapter “Basic Principles And Guidelines For Creating Shape And Size” (you can read it partially with Google Books: (link towards the correct chapter). It seems to be an interesting list of advices but still no methodology.
Thank you in advance.
PS: I have created the same thread in “Optistruct” forum section (Link) as my questions are related to both Optistruct and Inspire.
Best Regards,
Florent
