How Moldex3D correlates fiber simulations and products strength 2015 CSMA Taipei Joe Wang Technical Research Content > Introduction > Problem and challenges > Numerical investigation – Theory and assumption – Investigation Model and Information > Result and discussion > Summary 2 Introduction Lightweight Driven by CAFE Standard （ The Corporate Average Fuel Economy ） The Obama administration ushered in a new era of fuel efficiency standards by announcing aggressive new regulations that will nearly double fuel economy by 2025 to 54.5 miles per gallon 1 Liter  23.17 Km 4 Lightweight Driven by CAFE Standard 5 How to Achieve? > It may sound difficult, the technology to meet 54.5 mpg is well known and affordable. > Four key technologies needed: > Lightweight, high strength materials > Enhancing turbocharged gasoline engine efficiency > Improved, lower-cost hybrids technologies called “parallel 2-clutch” systems > Plug-in hybrids and battery electrics with lower cost, advanced lithium batteries 6 Injection Molding Lightweight Technologies Foaming 7 Fiber Co-injection Gas-assisted Inhomogeneous microstructure Crystallinity 8 Fiber orientation Polymer stretching Why isn’t broken at center? > Process Induced Anisotropy Source: Oak Ridge National Laboratory 9 Molecular origins 400K, 666 chains of [CH2]100 10 Jeffery’s orbit https://www.youtube.com/watch?v=5mmFs5MkhRI 11 Features of Fiber Orientation Distribution skin layer skin layer core width shell height shell height extreme point 12 Fiber length effect 13 Fiber content effect 30 wt% 50 wt% 14 Fiber matrix Interaction model polymer matrix coupling agent cluster aligned fiber flow direction 15 Fiber orientation from thermodynamic aspect 16 iARD-RPR Model for LFRT • US Patent and Journal of Rheology, 2013, Tseng and coworkers (Moldex3D) developed the three-parameter iARD-RPR fiber orientation model > The iARD model means the improvement of the ARD model > The RPR model is indicative of Retarding Principal Rate to slow down the fast transient orientation rate.  A  HD  A  iARD (C , C )  A  RPR ( ) A I M  HD  (W  A  A  W)   (D  A  A  D  2A : D) A 4 Jeffery hydrodynamics slow response rotary diffusion Best-Paper Award • US Society of Plastics Engineers (SEP) – Automotive Composites Conference & Exhibition (ACCE) 2013 – Three dimensional predictions of fiber orientation for injection molding of long fiber reinforced thermoplastics http://speautomotive.wordpress.com/2013/08/24/spe-announces-2013-acce-best-paper-winners/ Benefit of iARD-RPR Model > A simple formula with linear superposition  A  HD  A  iARD (C , C )  A  RPR ( ) A I M > Only three fitting parameters with physical meaning > Using inlet condition is particularly NOT necessary. > Correspondingly, ARD-RSC Model with a lot of parameters is complicated  ARD-RSC  W  A  A  W   {D  A  A  D  2[ A  (1   )(L  M : A )] : D} A 4 4 4 4  γ{2[D r  (1   )M 4 : D r ]  2tr(D r ) A  5(D r  A  A  D r )  10[ A 4  (1   )(L 4  M 4 : A 4 )] : D r }. b5 2 b4 D r  b1I  b2 A  b3 A  D  2 D γ γ 2 20 Patented technology 21 Plate-like talc filler (AR<1) Source: Granlund, et. al, JOURNAL OF POLYMER SCIENCE, PART B: POLYMER PHYSICS 2014, 52, 1157 22 Youngs modulus in the part 23 Digimat is the gateway UI Embedded Seamless Neutral file Process induced defects/anisotropy 24 Moldex3D-Digimat-LS DYNA simulation 製品CAD 樹脂流動解析配向アウトプット構造解析用Mesh作成連成解析実行配向マッピング性能評価材料モデル作成 25 連成解析パラメータ設定 25 Orientation mapping TO P モジュールを利用したプロセス □マッピングの目的 Meshの分割に，「樹脂流動＝細かい，構造解析＝粗い」の違いがあるため ※細かいMesh分割では構造解析の計算コストが過大となります．流動解析におけるウェルドライン位置（参考）流動解析用Mesh （細かいMesh分割）構造解析用Mesh （粗いMesh分割） Digimat-MAPによるマッピング結果 26 26 Impact results き裂パターン（モデル１）計算時間モデル１：1h 6m 4s モデル２：4h20m4s TO P 拘束位置ウェルドライン解析全体像 Headform反力履歴き裂パターン（モデル２）ー：モデル１（等方性）ー：モデル２（連成解析）ウェルド部にき裂連成計算では反力が1/2程度に低下 27 27 Fiber orientation effect > 本事例は，実機とのValidationを行っていませんので，繊維配向を考慮することによる定量的な評価はできませんが，解析結果から以下のことが示唆されます． – ダンベル試験結果より作成した等方性材料での強度評価は，危険側（過大な）評価となる可能性が高いです． – 繊維配向を考慮することで，ウェルドラインなどの流動パターンの影響による強度低下を考慮出来ます． X方向の配向 Y方向の配向ウェルドライン等方性材料では段差形状のためき裂が進展しにくいき裂の発生位置はウェルドを境に，急激に繊維の配向が変化している． 28 28 Fiber structural features Orientation http://www.en.emi.fraunhofer.de Length Concentration 29 Length degradation during plastication Feed section 30 Transition Meeting section section nozzle part Detailed screw size simulation Original length = 10 mm 加工條件 31 Unit：mm 塑化完纖維長度 Plastication 25RPM 1.93 Plastication 60RPM 1.10 Fiber mixed during compression zone 2.28 Fiber mixed during mertering zone，enlarged nozzle 5.74 Predicting manufacturability at design stage 1mm rib 0.5 mm rib This high concentration region suggests longer fibers accumulate before entering the thinner rib region. The fiber content in the rib region is smaller. 32 Complete fiber reinforced process portfolio Hybrid Short fiber Molding Compound Long fiber Resin Transfer Molding Fiber Mat compression Multi-component molding 33