| 摘要 |
摘要
隨著全球暖化加劇，以先進高強度鋼作為汽車結構件的材料已逐漸成為主流，相較於傳統的鋼板，先進高強度鋼板可以較薄的厚度達到相同之強度，在輕量化車體的同時也兼顧安全性。然而隨著板材強度提升，成形模具受到的力量負載也隨之提升，為了確保沖壓過程中時模具的結構強度，模具尺寸也跟著增加，除了增加材料的成本外，模具尺寸也受限於沖壓機台的沖程，並造成沖壓時的能耗更多。因此本研究嘗試應用拓樸優化於汽車板金件之成型模具的輕量化設計。
本研究首先利用專業的板金沖壓分析軟體PAM-STAMP
進行板材之沖壓模擬，得到模具在沖壓過程中受力的歷程。接著以結構分析軟體ABAQUS
進行模具的結構應力分析與拓樸優化設計，把模具沖壓模擬中的受力狀態作為邊界條件，並比較實心模具、考慮最大受力(單一工況)模具與多工況模具的三種結構表現，結果顯示考量多工況模具結構於沖壓歷程中之最大應力曲線較為平緩且最大位移曲線優於僅考量單工況之模具結構。
本研究比較業界實際載具汽車引擎蓋板傳統設計與拓樸優化設計的結構表現與減重效果，結果顯示拓樸優化結構在使用比傳統結構少7%的材料下，在沖壓歷程中最大應力曲線較為平緩，位移表現上優於傳統設計結構。由於汽車引擎蓋板對於精度要求高，因此必須盡量降低沖壓過程中之模面位移，本研究藉由局部結構優化提供一種不必整體重新設計，僅需局部修改結構之方法，可有效降低模面於受力最惡劣之狀況下的之位移。
關鍵字：先進高強度鋼、有限元素分析、輕量化、結構拓樸優化
Abstract
As global warming
becomes a serious issue, AHSS has been widely used as the
material of automobile structural parts. The strength of thinner
AHSS is as strong as traditional mild steel; therefore, AHSS
materials make automobile lighter but still safe. As the
strength of steels increases, more materials are used to produce
stamping die to ensure the strength of die structural can
sustain during metal sheet forming. However, it costs and
consumes more energy during stamping and transportation. This
study applies the topology optimization on sheet metal forming
die of automotive parts to achieve a lightweight design.
In order to proceed
topology optimization analysis, sheet metal forming simulation
is needed to extract the working condition of stamping die.
First, we used software, PAMSTAMP, to simulate the forming
process. Second, by taking advantage of software, ABAQUS, we
executed a structural stress analysis and topology optimization
with extracted critical working condition. Third, we compared
the optimized results of different boundary conditions, single
and multiple working conditions, and set geometric restriction
to ensure the final design was feasible. The result showed that
36% of the volume of material in s-rail case was saved compared
to solid structure; moreover, in hood case, 7% more material was
saved than traditional structure.
Besides lightweight
design, this study refers to the application of topology
optimization on structural enhancement methods to make stamping
die achieve better stiffness, and to secure the quality of the
product.
Key words: advanced high strength
steel, finite element analysis, lightweight design, topology
optimization
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