「Automatic processing of LS-DYNA models according to EuroNCAP and other protocols」 Arup, Advanced Technology & Research Richard Taylor 様
For crash safety consumer tests (NCAP, IIHS, etc), there are complex protocols for calculating and presenting results. To post-process LS-DYNA results into the format required is very time-consuming for the analyst. Arup Software Version 12 includes out-of-the-box templates for automatically post-processing LS-DYNA results according to these protocols, and generating reports in the correct style. In this presentation, we will show the reporting process for frontal ODB impact (EuroNCAP , IIHS and CNCAP); frontal FFB impact (EuroNCAP); frontal Small Offset Barrier (IIHS); side impact (EuroNCAP Side MDB and Side Pole); and pedestrian analysis (EuroNCAP). Additionally, we show an example of a fully automated process for pedestrian analysis, including pre-processing as well as post-processing.
「Metal flow line predictions and its application to metal forming process design」 MFRC Corporation Mechanical Engineering ManSoo Joun 様
Metal flow lines formed during metal forming have deep influence on the product quality of forged products. A new approach to predicting the three-dimensional metal flow lines is introduced. Some typical predictions of metal flow lines in forging and plate forging obtained using the new approach to predicting them are presented.
「Opportunities for innovation in metal forming simulation through hierarchical multi-scale material modelling」 KU Leuven (University of Leuven), Materials Engineering (MTM) Philip Eyckens 様
The concept of multi-scale material modeling has proven to drive innovation in manufacturing, at least for certain materials such as fiber-reinforced composites. Including microstructural aspects in CAE design enables further optimization of part performance and reduction in development cost. For metal alloys however, multi-scale design solutions are currently not yet widely applied in industry.
This lecture discusses multi-scale material modelling research for metal forming with focus on industrial applicability. An overview is given of the state-of-the-art multi-scale modeling approach. The macroscopic anisotropy is captured by including relevant microstructural aspects such as crystallographic texture and crystal substructure.
Three examples of formable steel illustrate the performance of the multi-scale model:
(i) the prediction of yield locus without any calibration needed from mechanical test data,
(ii) the prediction of differential hardening between different monotonic loading conditions on the basis of a single experimental stress-strain curve, and
(iii) the prediction of strain hardening stagnation or softening after strain path change through incorporation of the anisotropic dislocation substructure in the model.
Next, the applicability of such multi-scale material model to industrial (i.e. large-scale) forming processes is considered. The computational effort in FE analysis can be kept to acceptable level through the concept of the hierarchical multi-scale (HMS) material model. The HMS automatically evaluates the local deformation-induced changes in microstructure and provides the FE code with the corresponding evolution in properties of anisotropy and hardening. The coupling of HMS to FE simulation is automatic and has a manageable increase in overall computation time. The HMS concept is illustrated with FE simulations of a 2-stage industrial forming process that locally triggers Bauschinger and cross effects in the material, affecting final geometry and forming forces.
人体FEモデルTHUMSは交通事故時の傷害をコンピュータ上で再現・解析するために開発された。THUMS Version 4では人体骨格だけでなく脳・内臓の構造まで詳細に表現され、様々な事故形態における傷害発生メカニズムについて考察できるようになった。例えば、前面衝突時のシートベルトやエアバッグ荷重と胸部傷害リスクとの関係を調査、側面衝突時の肩を保持するエアバッグの効果、歩行者衝突時の衝突速度と頭部傷害リスクとの関係など。これらの調査結果は、傷害低減の一助となるような保護装置の開発や、傷害リスクの評価基準の改定に役立てるべく、国内外の研究開発活動の中で活用されている。
「シミュレーションベース手法エアバッグ折り畳みシステムJFOLD Version 2 - 新機能と折り畳み事例の紹介」 株式会社JSOL 林 信哉
CAEによる乗員安全解析においてエアバッグ展開解析の高精度化が求められていますが、複雑に折り畳まれたエアバッグモデルの作成が困難でした。このため、JSOLはLS-DYNA解析によりエアバッグの折り畳みを行うシミュレーションベース手法エアバッグ折り畳みシステムJFOLDを開発しました。JFOLDでは複雑な折り畳み工程をフローチャートで管理することにより、様々な折り畳みパターンのエアバッグモデルを作成することができます。本セッションではJFOLD Version 2の新機能とエアバッグの折り畳み事例を紹介します。
人体への安全性の向上をコンピューター上で再現するために開発されている人体傷害解析モデルTHUMS(Total Human Model for Safety)は、国内外で多くの技術者、研究者に活用されております。JSOLではTHUMSの販売代理店としてお客様にモデルをお届けするとともに、情報交換・共有のためユーザーコミュニティーの活性化の推進をしてまいりました。今回実施するTHUMSセッションをはじめ、国内、海外での活動状況をご報告します。