本研究係利用有限元素法模型，導入引擎的各主軸承之負載入力，透過MSC. Nastran求解引擎於中高轉速下(3200與4400 rpm)之振動，接著將引擎表面之振動速度匯入引擎之邊界元素法模型，經由VL Acoustics求得各轉速下之聲功率與聲壓分佈。結果顯示，油底殼元件之噪音量較大，故應對其進行結構強化，以降低其噪音量。在油底殼之模型上，運用應變分佈圖判斷肋條應佈建之部位，得以增加油底殼之剛性，提升該模態之自然頻率並避開其他模態，即可降低其振動量。
　　
運用上述技術，將油底殼原於底殼處之半月型與三角型肋條卸除，經改良後之剛性明顯增強，其自然頻率為1368 Hz，經與未卸除前之原頻率(1220 Hz)比較，頻率上升148 Hz。而新增之肋條總重為170克，較原半月型與三角型肋條高出110克，但此上升之幅度僅佔油底殼重量的2.5%，因此其增重尚可接受。

This study adopted the finite element model and imported the loading input force of each major engine bearings. The authors had MSC. Nastran's solving engine vibrated at medium to high rotation speed (3200 and 4400 rpm) and then imported the vibration speed of the engine surface to the engine’s boundary element model. Acoustic power and acoustic pressure distribution of each rotation speed were obtained from VL Acoustics. Our results suggest that the noise volume of oil pan component is higher, and thus its structure should be stiffened to reduce the noise volume. For the oil pan model, the study adopted strain distribution to determine the placement of ribs for stiffening the oil pan, elevating the natural frequency of the model, and keeping it away from other modes. These measures should be cable of reducing the vibration effectively.

According to the above-mentioned techniques, the authors removed the half-moon and the triangle ribs that are originally located at the bottom of the oil pan. After the modification, the stiffness was improved significantly and the natural frequency was increased to 1368 Hz, i.e., a 148 Hz increase from the original frequency (1220 Hz). The total weight of the newly added ribs was 170 g, which is 110 g heavier than the original half-moon and triangle ribs, yet this increase is only 2.5% of the total weight of the oil pan. In other words, this increase in weight is acceptable.

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