Timeline for Why do new engines have a case with a triangular tiling pattern?
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| Nov 24, 2020 at 22:20 | comment | added | Jpe61 | Yes. Antoni Gaudí modelled the structure of Sagrada Familia with strings and bags of sand almost 150 years ago. All kinds of modelling has been done for eons, modern computing has taken the optimization of structures to a whole new level. | |
| Nov 24, 2020 at 21:08 | comment | added | Kuba hasn't forgotten Monica | @Jpe61 Stress analysis has been "done" long ago using scaled models, manufactured from materials that are easier to work with. As long as the model is kept in the linear elastic region, and as long as there's no localized material anisotropy, then whatever you measure on the model applies (with proper scaling) to the full size structure. Some machined designs of this sort required dozens (sometimes >100) manually machined models as the optimization progressed. In some cases the models were machined wax, then investment cast, instrumented, loaded, measured, rinse and repeat. | |
| Nov 23, 2020 at 15:01 | comment | added | Jpe61 | Regardless of the pattern, if someone is aiming to optimize weight, strength, vibration etc, it will require computing power, which was not available at competitive cost, say, 50 years ago. The sizzling hot generative design patterns that are filling the newsfeed of anyone interested in this subject are a whole different question. But yes, the simplier lattices do not require ludicrous investments form R&D departments nowadays, hence they are more and more common these days. | |
| S Nov 23, 2020 at 14:14 | history | suggested | X X | CC BY-SA 4.0 |
Fix typo (chance -> change) and other minor mistakes
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| Nov 23, 2020 at 13:47 | comment | added | TooTea | Not sure what you're referring to regarding the required advanced computing capabilities, but note that the main reason for using equilateral triangles for the mesh (true "isogrid") is that it simplifies the design calculations a whole lot by making the properties of the whole lattice isotropic. A "waffle grid" (rectangular lattice) is much easier to manufacture but much harder to design. "advanced computing" actually enables more intricate and tailored lattice patterns than these two simple examples, so weird lattices have become a hot topic recently. | |
| Nov 23, 2020 at 13:47 | review | Suggested edits | |||
| S Nov 23, 2020 at 14:14 | |||||
| Nov 23, 2020 at 3:01 | comment | added | alephzero | It might seem that the wimpy little ribs would not add much stiffness. What is invisible in the pictures is that the outside of each triangular facet is flat, but the inside is curved to form a continuous smooth circular cylinder. Therefore the middle of each facet is very thin, but the ribs surrounding the triangle prevent any impact damage from an internal failure in the engine from spreading across the whole casing. (In fact, I remember one "accident" where the company making a prototype casing actually cut right through some of the thinnest sections while attempting to machine it!) | |
| Nov 22, 2020 at 20:29 | comment | added | Jpe61 | The structures you mention are somewhat different. The engine casings or shells in the pictures are are inseparable uniform solids, where as in the case of the airships and the V-A the skin and the grid were separate. Maybe glued or riveted together, dunno, but still separate "entities". | |
| Nov 22, 2020 at 18:07 | comment | added | Mark | You need to get fairly ancient: the Schütte-Lanz SL-1 utilized it in 1909, and Vickers-Armstrong used geodetic airframes in the 1930s. The calculations are complicated, though, which is why use of the technique only became common recently. | |
| Nov 22, 2020 at 17:47 | comment | added | jamesqf | I wouldn't say that it was at all uncommon in older times (depending on your definition of "more ancient". Consider the common I-beam, for example, or structures build using tubing rather than solid rods, e.g. the tube and fabric structure of older airplanes. | |
| Nov 22, 2020 at 17:19 | history | edited | Jpe61 | CC BY-SA 4.0 |
Typoooo
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| Nov 22, 2020 at 7:38 | history | answered | Jpe61 | CC BY-SA 4.0 |