注塑模具-3DCAE篇.pdf

真實三維CAE模擬 綱要 簡介簡介 為何需要為何需要3D CAE 模擬模擬 3D流動模擬材料性質流動模擬材料性質 數學模型與公式數學模型與公式 數值方法數值方法 3D流動模擬特殊議題流動模擬特殊議題 分析案例分析案例 3DCAE 模擬需求性模擬需求性 The Usefulness of Computer Aided Engineering CAE Simulation for Injection Molding Powerful and cost effective analysis tool virtual molding Insightful information for part mold and process designs Efficient search for optimal design and process set up Facilitate concurrent engineering by involving all parties As the computer performance and speed increase CAE simulations based on 3D approach will be more popular The later in time a product mold needs to be reworked the costlier that change becomes Cost Effective Analysis Tool cost of change manufacturing process part designmold design part manufacturing product delivery Insightful Information using CAE Velocity profile Temperature and pressure distributions Source Moldflow 設計與製程最適化設計與製程最適化 An integrated computer aided engineering CAE optimization tool that uses process simulation program to intelligently identify the optimal design and processing parameters Design and Processing Parameters Predictions Objective Function Computer Simulation Tool Optimization Scheme Tool CAE融滲的同步工程融滲的同步工程 Product Design Product Design Product Engineering Product Engineering Mold Design and Tooling Mold Design and Tooling Molding Molding Resin Supplier Resin Supplier CAECAECAE 為何需要為何需要3DCAE模擬模擬 Hele Shaw 流動模式的本質限制流動模式的本質限制 Creeping flows low Reynolds number Inertia force is negligible in polymer melt Velocity in gap wise direction is neglected Heat conduction in flow direction is negligible Wall thickness Overall part thickness Difficulty in constructing mid plane in 3D geometry 導致射出成型導致射出成型3D效應分析的限制效應分析的限制 3D 效應流動區域效應流動區域 Thick sections Fountain flows Sudden part thickness change Junctions i e ribs bosses and corners Inserts and special geometries i e grills Micro features and micro parts3D effects in the injection molding Source Michaeli W et al Kunststoffe 87 1997 4 三維厚件與複雜幾何三維厚件與複雜幾何 Source Moldflow 流道系統的流道系統的 3D 效應效應 The flow imbalance in the naturally balanced runner system PBT Flow rate 100 cc s Note that the inner cavities on the sprue sides are filled faster Source Costa F S et al Moldflow 慣性效應慣性效應 Fill patterns at a gate with flow rates of 970 cc s Re 4 0 using MPI FLOW3DTM Source Costa F S et al Moldflow w o inertia effect w inertia effect 微晶片的封裝微晶片的封裝 3D FE model Source Han R Poly Eng Sci March 2000 Vol 40 No 3 Hele Shaw model Cavity with leadframe and paddle is modeled by two sub cavities with a connector Source C MOLD 99 Online Books Modeler Visualizer Ch 3 黏度模型黏度模型 Source Chiang H H Cornell Injection Molding Program Technical Report No 62 Aug 1989 Commonly Used Viscosity Models Power law Bird Carreau Modified Cross 狀態方程式狀態方程式 pvT 模型 Schematic pvT diagrams for amorphous and crystalline polymers Source C MOLD 99 Online Books Reference Manual Ch 2 比熱模式比熱模式 AmorphousSemi Crystalline Schematic specific heat diagrams for amorphous and crystalline polymers Source C MOLD Reference Manual Ch 2 熱傳導係數模式熱傳導係數模式 Amorphous PC Semi Crystalline PP Schematic thermal conductivity diagrams for amorphous and crystalline polymers Source C MOLD Reference Manual Ch 2 統御方程式統御方程式 質量質量 動量動量 能量守恆能量守恆 0 u t g u p Dt D S T p T Dt DT c v p u uq 流 動 波 前 追 蹤流 動 波 前 追 蹤 Volume Tracking Methods based on Fixed Meshes The Marker and Cell MAC Method The Flow Analysis Network FAN Method The Volume of Fluid VOF Method The Pseudo Concentration Method A Volume Fraction Function F Filled cells F 1 Empty cells F 0 Surface cells 0 F t 0 t inlet x A typical volume fraction field Source Ashgriz N et al J of Computational Physics 93 1991 數值方法的應用數值方法的應用 1 Finite Difference Method 有限差分法 有限差分法 Relatively efficient and simple numerical method Difficulty in applying to irregular and complex domains 2 Finite Element Method 有限元素法 有限元素法 Excellent flexibility to treat complex geometry A large and sparse global system matrix 3 Boundary Element Method 邊界元素法 邊界元素法 Reduced dimensionality of solution by one i e 3D Solid 2D Surface More involved formulation than FEM and FDM 4 Control Volume Method 控制體積法 控制體積法 The integration domain is divided into control volumes Balance principles are applied to control volumes 厚度方向的解析度厚度方向的解析度 Elements with poor aspect ratio Excessive number of elements Meshed model with poor resolution 試 範 案 例試 範 案 例 Examples of 3D filling simulation using MPI FLOW3DTM Source Moldflow Melt front advancementShort shots 2 5D和和3D預測的流動圖案預測的流動圖案 The flow fronts by Hele Shaw model left and 3D model right Source Hetu J F et al Poly Eng Sci Feb 1998 Vol 38 No 2 2 5D預測齒輪產品的充填圖案預測齒輪產品的充填圖案 Fill patterns by Hele Shaw model with TPI Thermoplastic Polyimide using PLANETS3D Source Inoyama T Plamedia Research Corp 3D預測齒輪產品的充填圖案預測齒輪產品的充填圖案 More reasonable results in melt front advancement patterns by 3D model using PLANETS3D Source Inoyama T Plamedia Research Corp 肋骨氣道在肋骨氣道在2 5D氣輔成型的模型氣輔成型的模型 A rib model by meshing it as a series of 2 5D slices of varying thickness Source Potente H et al International Polymer Processing VIII 4 1993 肋骨氣道在肋骨氣道在3D氣輔成型的模型氣輔成型的模型 Source Haagh G A A V et al Poly Eng Sci March 2001 Vol 41 No 3 One half of meshed geometry and comparison of simulation left and experimental right results y 60mm 不平衡流道系統的溫度分佈不平衡流道系統的溫度分佈 3D simulation in a runner system Source Fluent Inc 自然平衡流道系統的溫度分佈自然平衡流道系統的溫度分佈 As the hotter material goes to the inner tertiary runners the inner cavities are filled faster Source Costa F S et al Moldflow 含角度澆口的流動慣性效應含角度澆口的流動慣性效應 Fill patterns for an angled gate with a flow rate of 37 cc s Re 15 4 using MPI FLOW3DTM Source Costa F S et al Moldflow w o inertia effect w inertia effect 3D CAE軟體發展面臨的挑戰軟體發展面臨的挑戰 Numerical Solution for Multiphase Compressible Flow Model is not Easy Numerical Solution for Elongation Flow Effe