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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.
9 v# J6 n& m9 ~: k5 f+ O; x5 ^In 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.& P1 }4 N9 ~  x4 i  Y4 `$ U- N
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Analysis (computational) times are much lower for shellsthan solid geometry.4 n: _9 N* L: |
Furthermore, laminar edges (coincident surfaces) aretreated as bonded, so there is no need to worry about knitting your surfacesbefore starting your analysis.$ h2 E6 `1 a( I: w& @( v
[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.
1 l0 s; [" E+ x1 `% yThe main forces applied to the bike are torsional andlateral forces. Therefore, we can limit our analysis to torsional and lateralstiffness.0 o4 O6 c! u) ^8 a: w1 J: k/ r
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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.! e/ k! j# G7 Z
First, 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).* u5 O7 f7 c) o( n) T# ]9 F
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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.
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Thank you for reading, stay tuned forthe next part!
Summary of results
    
Design Aspect
      
Change In Stiffness (%)
  
6 b) Z  h/ O2 W( d  u8 {" |     
Non-Circular Profile
      
37 (Torsional)
   % F/ [9 H+ c" G+ Y! A4 `: b
    
Tapered Head Tube
      
21.5 (Torsional)
   4 W3 J) H4 x/ Y1 Y& t" T
    
Non-Symmetric Chain Stay
      
11 (Lateral)
  
# N: v- P5 T7 Y2 @4 U/ ?     
Seat Stay (+/- 1 mm thickness)
      
<<1 (Torsional/Lateral)
   ! j+ ~, \3 K9 ^- u" P% a
    
Top Tube Taper (1 1/10)
      
3 (Torsional): k1 m8 E, a; f1 f' y) {9 E

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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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