Optimization of Plastic Parts. 3:00 pm – Arrival & introductions 3:20 pm – Department overview & tour (Robert Malloy) 3:40 pm – Toyota questions & discussion (all) 4:40 pm – Simulation technology (Francis Lai) 5:00 pm – Optimization, simulation , and control (David Kazmer)
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Optimization of Plastic Parts • 3:00 pm – Arrival & introductions • 3:20 pm – Department overview & tour (Robert Malloy) • 3:40 pm – Toyota questions & discussion (all) • 4:40 pm – Simulation technology (Francis Lai) • 5:00 pm – Optimization, simulation , and control (David Kazmer) • 6:15 pm – Depart Univ. Mass. Lowell • 6:30 pm – Dinner at Cobblestones
INTRODUCTION HOSTS John Ting, Univ. Mass. Lowell Dean, College of Engineering Former Chair of Department of Civil Engineering. Specialist in computer modeling and development ofmaterials and structures. Robert Malloy, Univ. Mass. Lowell Chair, Department of Plastics Engineering Specialist in molded part design, plastics recycling,and injection molding. Author of Introduction to Plastic Part Design. Fang (Francis) Lai, Univ. Mass. Lowell Professor, Department of Plastics Engineering Specialist in plastics processing, process control and instrumentation, CAE in plastics processing, powder technology, SQC/SPC, and statistical methods. David Kazmer, Univ. Mass. Lowell Associate Professor, Department of Plastics Engineering Specialist in integrated product-process design using concurrent simulation, optimization, and control systemdevelopment. Chair of ASME DFM Committee, PPS MoldingTechnology Symposium.
INTRODUCTION VISITORS Tadayoshi TAKAHARA, Toyota Motor Co. General Assembly Plastics Engineering Div. Group Manager. In the field of plastic parts, responsible for the application and management of CAE and injection molding process. Makoto YOSHINAGA, Toyota Motor Co. General Assembly Plastics Engineering Div. Engineer. Specialized on CAE and product development in the field of plastic parts. Hiroshi FURUHASHI, DENSO Co. Production Engineering R&D Dept. Senior Manager. In the field of parts processing, responsible for the application and management of digital technology and electronic packaging and assembly technology
INTRODUCTION VISITORS Kazumichi YAMADA, Toyoda Gosei Co.,LTD Technical Planning Dept. Group Manager. Responsible for the application and management of digital technology, mainly composed of CAE, in the field of plastic parts. Hiroshi KOYAMA, Toyota Boshoku Co. Filter & Power Train Components Production Engineering Div. Manager. Responsible for the development and management of polymer processing technology for automobile filters and power train components. Ikuo IMAIZUMI, Kanto Auto Works, Ltd. Production EngineeringⅡ Div. Assistant Manager. Specialized on CAE in the field of plastic parts.
1. Now a day, there is a movement to use optimization for product development. We are anxious about technical level and knowledge of the engineer in our company decrease. Could you tell us the countermeasure?昨今、最適化を定常業務に取り込む動きがある中、技術員の能力、知見の低下が問題になることが予想される。良い対策が有りましたら教えて下さい。
Background • Perfect product does not exist – can always improve • Optimization is a powerful tool, but often underutilized • Real products have many constraints and objectives. • Uncertainty is a critical issue • Constraints, objectives, and behavior • Example: instrument panel • Objectives: Shrinkage, warpage, weight, stiffness, … • Constraints: pressure, tonnage, cycle time, … • Performance roughly known
Suggestions • Three-level approach: • First, develop and validate analysis capability to know error bounds (confidence intervals) • May need to minimize the number of different materials or geometries to ensure high fidelity results • Second, develop an optimization process with standard specifications but tight manufacturing constraints • Third, use flexibility of manufacturing processes to adjust the quality of the manufactured products, and thereby avoid costly redevelopment • If the analysis and optimization in steps (1) and (2) were accurate, then step (3) may be used to reduce cost.
2. Could you tell us the level of optimization analysis and robust analysis in Automotive maker, Aircraft maker and electronic maker in the world?世間の自動車メーカー、航空機メーカー、家電メーカーでの最適化解析、ロバスト解析のレベルをご存知の範囲で教えて下さい。
Background • Consider Boeing, General Motors Research, Delphi, AMP • Optimization on component level • Finite element simulation • Constrained optimization of stress, temperature, … • Little system-level optimization • Organizational and functional interface issues • Best: stochastic tolerancing in assemblies • Need to consider variations in manufacturing & end-use
3. Could you tell us the direction of CAE technology development for the optimization analysis and the efficient tool? 今後の最適化ソフト、効率化ソフトの開発の方向性を教えて下さい。
Background • Simulation moving from 2D to 3D • More CPU and easier meshing • Not always more accurate • Better material modeling • Elongational & viscoelastic flows • Most important: Application Programming Interface • API provides direct access between CAD, simulation, and optimization • API allows modeling of complex boundary conditions • Multi-material assemblies, complex molds, …
Suggestions • Simulation and optimization should be conducted for the injection mold assembly • Incorporate coupled field analyses for: • deflection of mold plates • true 3D heat transfer • much better part stress/shrinkage/warpage • Better analysis accuracy and mold design. • Later, CAE should be performed at the press to predict part quality based on real time feedback from molding sensors. • Process conditions and quality issues given back to development team.
4. We are studying the mold specification (product thickness, gate position) by using optimization method(L81+RSM). It takes 2.5days to obtain the result because there are many caluculations of flow analysis. Could you tell us the countermeasure? We would like to obtain the result by minimum sampling. 射出成形部品の型仕様（板厚分布、ゲート配置）の検討（Ｌ８１＋ＲＳＭ）を試行中。計算回数が多く、２.５日かかる。少ないサンプリングから的確な解を出す手法があれば、可能性を含めて教えて下さい。
Background • L81 is quite a design! • Second order effects (both square and linear interactions) are important and should be analyzed. • Higher order effects are probably not reasonable to look at, and might imply a false level of simulation fidelity. • Important to reduce the optimization time
Suggestions • Reduce the number of factors by assuming standard or conservative conditions. • Decomposing the L81 into two or three uncoupled DOEs • Consider a parallel cluster of CPUs to run the analyses in parallel. • The good news is that analysis time will likely drop by 50% in the next year with X64, multiple cores, and increased memory bandwidth.
5. In the future, we would like to consider the deviation of molding process(injection pressure, resin temperature, mold tempereture etc) and to study the strongly robustic design of mold. Could you tell us how to incorporate the idea? 今後、成形バラツキ（射出圧力、樹脂温度、型温度）を考慮し、ロバストに強い型仕様を検討したい。考え方をどう組み込めば良いですか？
Background • Very good idea • Reduce failure rates • Improve yields and reduce costs
Suggestions • Four step approach • Use Taguchi inner/outer array to characterize the dependence across a broad range of conditions, with linear main effects. • Use the moment matching method to estimate the expected part quality variations. • Adjust the design specifications for optimization. • Improve manufacturing processes • Identify & improve inconsistent process parameters • Use manufacturing flexibility to improve quality
6. Could you tell us how to confirm the accuracy of analysis for optimization? We have just started to study optimization and had a few idea. 最適化に関する解析や分析の精度確認の考え方を教えて下さい。
Background & Suggestions • Knowing analysis accuracy is important • Conservative assumption: added expense or no feasibility • No conservative assumption: high failure rates & rework • Two issues regarding accuracy • First, simulation may not reflect reality • Perform extensive validation program… 30%+ errors • Second, the response surfaces may not reflect simulation • Use RSM analysis to provide confidence intervals • Validate with a few unfit simulation results
7. Could you tell us your available software or your recommend software for optimization? 使用しているソフト、或いは推奨の最適化ソフトがあれば教えて下さい。
Background • An optimization package should • Handle multiple constraints & objectives • Converge consistently & quickly • Handle complex functions • Provide sensitivity functions at optima • Have an Application Program Interface or source code
Suggestions • Programmable • Numerical Recipes in C • Matlab: Programmable, I/O files, graphics • Many many others • Global optimization, linear and nonlinear optimization, unconstrained, constrained, least squares, MCP (multi-complementarity problem), multi-objective optimization, discrete optimization, approximation • Two sites • http://plato.asu.edu/topics/problems.html • http://www.numerical.rl.ac.uk/external/optimization.shtml