- 學位論文
利用陶瓷壓電振動激化複合材料表面螺紋印現象
The Study of Exciting Print-Through Phenomenon on the Surface of GFRP Materials by using Piezoelectric Vibration
摘要
真空輔助樹脂灌注成型法(Vacuum Assisted Resin Transfer Molding，簡稱VARTM)是纖維補強強化塑膠(Glass Fiber-Reinforced-Plastic，簡稱GFRP)的先進製程之一，而是用Seemann公司專利樹脂導流網(俗稱黑網)的VARTM則稱為Seemann Composite Resin Infusion Molding Process，簡稱為SCRIMP。Print-Through Phenomenon，簡稱 PTP，的產生的主要原因為樹脂硬化反應完成後的溫差作用，使不同熱膨脹係數的材料有不同的收縮量，造成樹脂體積收縮以及殘餘應力產生，而使膠殼產生PTP；此外，在SCRIMP製程中，所受到的大氣壓力亦會產生殘餘應力。 對於PTP的研究，本文以表面性質振幅參數中的平均粗糙度Ra的定量量測，客觀的判斷不同試片表面PTP的嚴重程度，另外，由實驗的結果亦可發現，PTP可由表面的拋光研磨而被消除，所以PTP是材料表面的微小局部變形的結果。 在探討PTP的過程中，利用壓電陶瓷對於驅動頻率的改變，可以提早將試片內部之殘餘應力釋放，加速PTP的產生。驅動頻率的選擇對於PTP的產生有很大的影響，本論文提出了三種頻率驅動並對於結果做定性的量測來觀察PTP。並且，利用ABAQUSTM有限元素軟體模擬試片經由驅動頻率令壓電陶瓷振動產生之模態和其對振動對試片內部釋放應力之主要變數。
並列摘要
Vacuum Assisted Resin Transfer Molding (abbr. VARTM) is one of the advanced molding processes of Glass Fiber-Reinforced-Plastic (abbr. GFRP). If the resin flow medium patented by Seemann Corp. is used in VARTM, the process will be called Seemann Composite Resin Infusion Molding Process (abbr. SCRIMP).The main reason that caused PTP is due to thermal shrinkage of the plastic matrix during cooling process. Furthermore, the atmospheric pressure during SCRIMP process is one of the main reason that produce residual stress. For the study of Print-Through Phenomenon (abbr.PTP), the amplitude parameter of the surface texture properties has been carried out, the average roughness (Ra) is measured to objectively determine the existence of PTP and its level. Besides that, the measuring results also revealed that PTP can be eliminated by polishing the surface of GFRP. Therefore, PTP is a visual problem of the tiny deformation of the surface. This paper presents three frequency levels by using piezoelectric to vibrate the GFRP specimens and discovered that it could accelerate the PTP reveal on the gel-coating surface effectively by using the average roughness (Ra) above to determine the existence of PTP and its level. Frequency remain an important factor that in accelerating the PTP. In this paper has further discussing on choosing the appropriate frequency and its results. By using ABAQUS to simulate the main variable that control residual stress relief in the GFRP specimen.