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標(biāo)題: Solidworks smulation 設(shè)計(jì)分析自行車車架 [打印本頁]
作者: 寂靜天花板 時(shí)間: 2015-9-24 19:05
標(biāo)題: Solidworks smulation 設(shè)計(jì)分析自行車車架
Part 1: Frame Geometry Optimization – Using 3D Sketches, Weldments, and StaticAnalysis to optimize the frame geometry
Part 2: Tube Shape Optimization 1 – UsingSurfacing and Static Analysis to define the shape of the tubes
Part 3: Tube Shape Optimization 2 – UsingCFD analysis to optimize the aerodynamic efficiency of the tube shapes
Part 4: Components and Details – Finishingup the rest of the bike. Because why not?
用3D草圖、焊件和靜態(tài)算例，優(yōu)化車架幾何結(jié)構(gòu)，再用CFD分析，從空氣動(dòng)力學(xué)角度優(yōu)化管形狀。
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上圖吧。
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When we want to incorporate FEA techniques in ouranalysis, we should consider ways to simplify our model. A bike frame has avery small thickness relative to its surface area. Therefore, we can analyzethe geometry using shells.
) G5 }: Q4 I8 {/ sIn SOLIDWORKS, shells are very easy to set up. With thehelp of the Shell Manager,surfaces can be given a thickness, material, offset type, and more within oneconvenient table.# O- m3 w3 i" K' x+ K: y) N
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Analysis (computational) times are much lower for shellsthan solid geometry.0 |4 w7 p; c, e% _
Furthermore, laminar edges (coincident surfaces) aretreated as bonded, so there is no need to worry about knitting your surfacesbefore starting your analysis.' i* Q$ j m: l$ P0 f
[attach]365869[/attach]Tapered vs. Non-Tapered Head TubeThere is quite a lot of hype about ‘tapered head tubes’ inthe performance cycling world [where the bottom profile of the head tube tapersout], but how much of a difference does it actually make? To find out, I ran astatic analysis to see if there was any noticeable effect on the frame’sstiffness.
9 `7 n. V& U- |4 N& L! T- gThe main forces applied to the bike are torsional andlateral forces. Therefore, we can limit our analysis to torsional and lateralstiffness.4 \# _6 J7 x3 X- m" _) c
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These are simplified definitions for a body with onedegree of freedom. This can be applied to our case by analyzing the resultantdeflection in the direction of the applied force as long as one force isapplied at a time for each analysis.
, X! x/ ?" D- g6 pFirst, let’s look at the torsional stiffness. In order tocalculate torsional stiffness (for the Head Tube) we can create a resultantplot of the circumferential deflection about the Head Tube Axis (HT AXIS).
7 V# U [( ]) \! g[attach]365866[/attach][attach]365867[/attach]
By taking advantage of the extra spaceon the non-drive side, I was able to increase the lateral stiffness of theframe by 11%.
In the next part, I will furtherimprove the performance of the frame design by using CFD (computational fluiddynamics) analysis to optimize for aerodynamic performance.
[attach]365868[/attach]Thank you for reading, stay tuned forthe next part!
Summary of results
Design Aspect
Change In Stiffness (%)
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Non-Circular Profile
37 (Torsional)
( a; n, l& ]! ~+ `( {/ ` Tapered Head Tube
21.5 (Torsional)
& w. W2 K0 s; w9 f* }
Non-Symmetric Chain Stay
11 (Lateral)
7 w3 H. b. D0 Q3 {6 K Seat Stay (+/- 1 mm thickness)
<<1 (Torsional/Lateral)
: x& a m' K6 \ ]( y2 ] Top Tube Taper (1 1/10)
3 (Torsional)
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2 ~% Z ]8 z2 o# M% P, A這篇文章給人印象深刻的不是分析，而是自行車架的3D草圖。不要抱怨軟件如何如何，還是多檢討自己吧。
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